Adding upstream version 2.4.1.upstream/2.4.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

28 files changed, 14817 insertions, 0 deletions

diff --git a/src/share/database/scripts/pgsql/Makefile.am b/src/share/database/scripts/pgsql/Makefile.am
new file mode 100644
index 0000000..b38c380
--- /dev/null
+++ b/src/share/database/scripts/pgsql/Makefile.am
@@ -0,0 +1,39 @@
+SUBDIRS = .
+
+pgsqldir = ${datarootdir}/${PACKAGE_NAME}/scripts/pgsql
+
+# non-executable
+pgsql_DATA  =
+pgsql_DATA += dhcpdb_create.pgsql
+pgsql_DATA += dhcpdb_drop.pgsql
+
+# executable
+pgsql_SCRIPTS  =
+pgsql_SCRIPTS += upgrade_001.0_to_002.0.sh
+pgsql_SCRIPTS += upgrade_002.0_to_003.0.sh
+pgsql_SCRIPTS += upgrade_003.0_to_003.1.sh
+pgsql_SCRIPTS += upgrade_003.1_to_003.2.sh
+pgsql_SCRIPTS += upgrade_003.2_to_003.3.sh
+pgsql_SCRIPTS += upgrade_003.3_to_004.0.sh
+pgsql_SCRIPTS += upgrade_004.0_to_005.0.sh
+pgsql_SCRIPTS += upgrade_005.0_to_005.1.sh
+pgsql_SCRIPTS += upgrade_005.1_to_006.0.sh
+pgsql_SCRIPTS += upgrade_006.0_to_006.1.sh
+pgsql_SCRIPTS += upgrade_006.1_to_006.2.sh
+pgsql_SCRIPTS += upgrade_006.2_to_007.0.sh
+pgsql_SCRIPTS += upgrade_007_to_008.sh
+pgsql_SCRIPTS += upgrade_008_to_009.sh
+pgsql_SCRIPTS += upgrade_009_to_010.sh
+pgsql_SCRIPTS += upgrade_010_to_011.sh
+pgsql_SCRIPTS += upgrade_011_to_012.sh
+pgsql_SCRIPTS += upgrade_012_to_013.sh
+pgsql_SCRIPTS += upgrade_013_to_014.sh
+pgsql_SCRIPTS += upgrade_014_to_015.sh
+pgsql_SCRIPTS += upgrade_015_to_016.sh
+pgsql_SCRIPTS += upgrade_016_to_017.sh
+pgsql_SCRIPTS += upgrade_017_to_018.sh
+pgsql_SCRIPTS += wipe_data.sh
+
+DISTCLEANFILES = ${pgsql_SCRIPTS}
+
+EXTRA_DIST = ${pgsql_DATA}
diff --git a/src/share/database/scripts/pgsql/Makefile.in b/src/share/database/scripts/pgsql/Makefile.in
new file mode 100644
index 0000000..14bd659
--- /dev/null
+++ b/src/share/database/scripts/pgsql/Makefile.in
@@ -0,0 +1,924 @@
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+ac_ct_CC = @ac_ct_CC@
+ac_ct_CXX = @ac_ct_CXX@
+ac_ct_DUMPBIN = @ac_ct_DUMPBIN@
+am__include = @am__include@
+am__leading_dot = @am__leading_dot@
+am__quote = @am__quote@
+am__tar = @am__tar@
+am__untar = @am__untar@
+bindir = @bindir@
+build = @build@
+build_alias = @build_alias@
+build_cpu = @build_cpu@
+build_os = @build_os@
+build_vendor = @build_vendor@
+builddir = @builddir@
+datadir = @datadir@
+datarootdir = @datarootdir@
+docdir = @docdir@
+dvidir = @dvidir@
+exec_prefix = @exec_prefix@
+host = @host@
+host_alias = @host_alias@
+host_cpu = @host_cpu@
+host_os = @host_os@
+host_vendor = @host_vendor@
+htmldir = @htmldir@
+includedir = @includedir@
+infodir = @infodir@
+install_sh = @install_sh@
+libdir = @libdir@
+libexecdir = @libexecdir@
+localedir = @localedir@
+localstatedir = @localstatedir@
+mandir = @mandir@
+mkdir_p = @mkdir_p@
+oldincludedir = @oldincludedir@
+pdfdir = @pdfdir@
+pkgpyexecdir = @pkgpyexecdir@
+pkgpythondir = @pkgpythondir@
+prefix = @prefix@
+program_transform_name = @program_transform_name@
+psdir = @psdir@
+pyexecdir = @pyexecdir@
+pythondir = @pythondir@
+runstatedir = @runstatedir@
+sbindir = @sbindir@
+sharedstatedir = @sharedstatedir@
+srcdir = @srcdir@
+sysconfdir = @sysconfdir@
+target_alias = @target_alias@
+top_build_prefix = @top_build_prefix@
+top_builddir = @top_builddir@
+top_srcdir = @top_srcdir@
+SUBDIRS = .
+pgsqldir = ${datarootdir}/${PACKAGE_NAME}/scripts/pgsql
+
+# non-executable
+pgsql_DATA = dhcpdb_create.pgsql dhcpdb_drop.pgsql
+
+# executable
+pgsql_SCRIPTS = upgrade_001.0_to_002.0.sh upgrade_002.0_to_003.0.sh \
+	upgrade_003.0_to_003.1.sh upgrade_003.1_to_003.2.sh \
+	upgrade_003.2_to_003.3.sh upgrade_003.3_to_004.0.sh \
+	upgrade_004.0_to_005.0.sh upgrade_005.0_to_005.1.sh \
+	upgrade_005.1_to_006.0.sh upgrade_006.0_to_006.1.sh \
+	upgrade_006.1_to_006.2.sh upgrade_006.2_to_007.0.sh \
+	upgrade_007_to_008.sh upgrade_008_to_009.sh \
+	upgrade_009_to_010.sh upgrade_010_to_011.sh \
+	upgrade_011_to_012.sh upgrade_012_to_013.sh \
+	upgrade_013_to_014.sh upgrade_014_to_015.sh \
+	upgrade_015_to_016.sh upgrade_016_to_017.sh \
+	upgrade_017_to_018.sh wipe_data.sh
+DISTCLEANFILES = ${pgsql_SCRIPTS}
+EXTRA_DIST = ${pgsql_DATA}
+all: all-recursive
+
+.SUFFIXES:
+$(srcdir)/Makefile.in:  $(srcdir)/Makefile.am  $(am__configure_deps)
+	@for dep in $?; do \
+	  case '$(am__configure_deps)' in \
+	    *$$dep*) \
+	      ( cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh ) \
+	        && { if test -f $@; then exit 0; else break; fi; }; \
+	      exit 1;; \
+	  esac; \
+	done; \
+	echo ' cd $(top_srcdir) && $(AUTOMAKE) --foreign src/share/database/scripts/pgsql/Makefile'; \
+	$(am__cd) $(top_srcdir) && \
+	  $(AUTOMAKE) --foreign src/share/database/scripts/pgsql/Makefile
+Makefile: $(srcdir)/Makefile.in $(top_builddir)/config.status
+	@case '$?' in \
+	  *config.status*) \
+	    cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh;; \
+	  *) \
+	    echo ' cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__maybe_remake_depfiles)'; \
+	    cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__maybe_remake_depfiles);; \
+	esac;
+
+$(top_builddir)/config.status: $(top_srcdir)/configure $(CONFIG_STATUS_DEPENDENCIES)
+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
+
+$(top_srcdir)/configure:  $(am__configure_deps)
+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
+$(ACLOCAL_M4):  $(am__aclocal_m4_deps)
+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
+$(am__aclocal_m4_deps):
+upgrade_001.0_to_002.0.sh: $(top_builddir)/config.status $(srcdir)/upgrade_001.0_to_002.0.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_002.0_to_003.0.sh: $(top_builddir)/config.status $(srcdir)/upgrade_002.0_to_003.0.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_003.0_to_003.1.sh: $(top_builddir)/config.status $(srcdir)/upgrade_003.0_to_003.1.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_003.1_to_003.2.sh: $(top_builddir)/config.status $(srcdir)/upgrade_003.1_to_003.2.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_003.2_to_003.3.sh: $(top_builddir)/config.status $(srcdir)/upgrade_003.2_to_003.3.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_003.3_to_004.0.sh: $(top_builddir)/config.status $(srcdir)/upgrade_003.3_to_004.0.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_004.0_to_005.0.sh: $(top_builddir)/config.status $(srcdir)/upgrade_004.0_to_005.0.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_005.0_to_005.1.sh: $(top_builddir)/config.status $(srcdir)/upgrade_005.0_to_005.1.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_005.1_to_006.0.sh: $(top_builddir)/config.status $(srcdir)/upgrade_005.1_to_006.0.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_006.0_to_006.1.sh: $(top_builddir)/config.status $(srcdir)/upgrade_006.0_to_006.1.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_006.1_to_006.2.sh: $(top_builddir)/config.status $(srcdir)/upgrade_006.1_to_006.2.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_006.2_to_007.0.sh: $(top_builddir)/config.status $(srcdir)/upgrade_006.2_to_007.0.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_007_to_008.sh: $(top_builddir)/config.status $(srcdir)/upgrade_007_to_008.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_008_to_009.sh: $(top_builddir)/config.status $(srcdir)/upgrade_008_to_009.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_009_to_010.sh: $(top_builddir)/config.status $(srcdir)/upgrade_009_to_010.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_010_to_011.sh: $(top_builddir)/config.status $(srcdir)/upgrade_010_to_011.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_011_to_012.sh: $(top_builddir)/config.status $(srcdir)/upgrade_011_to_012.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_012_to_013.sh: $(top_builddir)/config.status $(srcdir)/upgrade_012_to_013.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_013_to_014.sh: $(top_builddir)/config.status $(srcdir)/upgrade_013_to_014.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_014_to_015.sh: $(top_builddir)/config.status $(srcdir)/upgrade_014_to_015.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_015_to_016.sh: $(top_builddir)/config.status $(srcdir)/upgrade_015_to_016.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_016_to_017.sh: $(top_builddir)/config.status $(srcdir)/upgrade_016_to_017.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+upgrade_017_to_018.sh: $(top_builddir)/config.status $(srcdir)/upgrade_017_to_018.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+wipe_data.sh: $(top_builddir)/config.status $(srcdir)/wipe_data.sh.in
+	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
+install-pgsqlSCRIPTS: $(pgsql_SCRIPTS)
+	@$(NORMAL_INSTALL)
+	@list='$(pgsql_SCRIPTS)'; test -n "$(pgsqldir)" || list=; \
+	if test -n "$$list"; then \
+	  echo " $(MKDIR_P) '$(DESTDIR)$(pgsqldir)'"; \
+	  $(MKDIR_P) "$(DESTDIR)$(pgsqldir)" || exit 1; \
+	fi; \
+	for p in $$list; do \
+	  if test -f "$$p"; then d=; else d="$(srcdir)/"; fi; \
+	  if test -f "$$d$$p"; then echo "$$d$$p"; echo "$$p"; else :; fi; \
+	done | \
+	sed -e 'p;s,.*/,,;n' \
+	    -e 'h;s|.*|.|' \
+	    -e 'p;x;s,.*/,,;$(transform)' | sed 'N;N;N;s,\n, ,g' | \
+	$(AWK) 'BEGIN { files["."] = ""; dirs["."] = 1; } \
+	  { d=$$3; if (dirs[d] != 1) { print "d", d; dirs[d] = 1 } \
+	    if ($$2 == $$4) { files[d] = files[d] " " $$1; \
+	      if (++n[d] == $(am__install_max)) { \
+		print "f", d, files[d]; n[d] = 0; files[d] = "" } } \
+	    else { print "f", d "/" $$4, $$1 } } \
+	  END { for (d in files) print "f", d, files[d] }' | \
+	while read type dir files; do \
+	     if test "$$dir" = .; then dir=; else dir=/$$dir; fi; \
+	     test -z "$$files" || { \
+	       echo " $(INSTALL_SCRIPT) $$files '$(DESTDIR)$(pgsqldir)$$dir'"; \
+	       $(INSTALL_SCRIPT) $$files "$(DESTDIR)$(pgsqldir)$$dir" || exit $$?; \
+	     } \
+	; done
+
+uninstall-pgsqlSCRIPTS:
+	@$(NORMAL_UNINSTALL)
+	@list='$(pgsql_SCRIPTS)'; test -n "$(pgsqldir)" || exit 0; \
+	files=`for p in $$list; do echo "$$p"; done | \
+	       sed -e 's,.*/,,;$(transform)'`; \
+	dir='$(DESTDIR)$(pgsqldir)'; $(am__uninstall_files_from_dir)
+
+mostlyclean-libtool:
+	-rm -f *.lo
+
+clean-libtool:
+	-rm -rf .libs _libs
+install-pgsqlDATA: $(pgsql_DATA)
+	@$(NORMAL_INSTALL)
+	@list='$(pgsql_DATA)'; test -n "$(pgsqldir)" || list=; \
+	if test -n "$$list"; then \
+	  echo " $(MKDIR_P) '$(DESTDIR)$(pgsqldir)'"; \
+	  $(MKDIR_P) "$(DESTDIR)$(pgsqldir)" || exit 1; \
+	fi; \
+	for p in $$list; do \
+	  if test -f "$$p"; then d=; else d="$(srcdir)/"; fi; \
+	  echo "$$d$$p"; \
+	done | $(am__base_list) | \
+	while read files; do \
+	  echo " $(INSTALL_DATA) $$files '$(DESTDIR)$(pgsqldir)'"; \
+	  $(INSTALL_DATA) $$files "$(DESTDIR)$(pgsqldir)" || exit $$?; \
+	done
+
+uninstall-pgsqlDATA:
+	@$(NORMAL_UNINSTALL)
+	@list='$(pgsql_DATA)'; test -n "$(pgsqldir)" || list=; \
+	files=`for p in $$list; do echo $$p; done | sed -e 's|^.*/||'`; \
+	dir='$(DESTDIR)$(pgsqldir)'; $(am__uninstall_files_from_dir)
+
+# This directory's subdirectories are mostly independent; you can cd
+# into them and run 'make' without going through this Makefile.
+# To change the values of 'make' variables: instead of editing Makefiles,
+# (1) if the variable is set in 'config.status', edit 'config.status'
+#     (which will cause the Makefiles to be regenerated when you run 'make');
+# (2) otherwise, pass the desired values on the 'make' command line.
+$(am__recursive_targets):
+	@fail=; \
+	if $(am__make_keepgoing); then \
+	  failcom='fail=yes'; \
+	else \
+	  failcom='exit 1'; \
+	fi; \
+	dot_seen=no; \
+	target=`echo $@ | sed s/-recursive//`; \
+	case "$@" in \
+	  distclean-* | maintainer-clean-*) list='$(DIST_SUBDIRS)' ;; \
+	  *) list='$(SUBDIRS)' ;; \
+	esac; \
+	for subdir in $$list; do \
+	  echo "Making $$target in $$subdir"; \
+	  if test "$$subdir" = "."; then \
+	    dot_seen=yes; \
+	    local_target="$$target-am"; \
+	  else \
+	    local_target="$$target"; \
+	  fi; \
+	  ($(am__cd) $$subdir && $(MAKE) $(AM_MAKEFLAGS) $$local_target) \
+	  || eval $$failcom; \
+	done; \
+	if test "$$dot_seen" = "no"; then \
+	  $(MAKE) $(AM_MAKEFLAGS) "$$target-am" || exit 1; \
+	fi; test -z "$$fail"
+
+ID: $(am__tagged_files)
+	$(am__define_uniq_tagged_files); mkid -fID $$unique
+tags: tags-recursive
+TAGS: tags
+
+tags-am: $(TAGS_DEPENDENCIES) $(am__tagged_files)
+	set x; \
+	here=`pwd`; \
+	if ($(ETAGS) --etags-include --version) >/dev/null 2>&1; then \
+	  include_option=--etags-include; \
+	  empty_fix=.; \
+	else \
+	  include_option=--include; \
+	  empty_fix=; \
+	fi; \
+	list='$(SUBDIRS)'; for subdir in $$list; do \
+	  if test "$$subdir" = .; then :; else \
+	    test ! -f $$subdir/TAGS || \
+	      set "$$@" "$$include_option=$$here/$$subdir/TAGS"; \
+	  fi; \
+	done; \
+	$(am__define_uniq_tagged_files); \
+	shift; \
+	if test -z "$(ETAGS_ARGS)$$*$$unique"; then :; else \
+	  test -n "$$unique" || unique=$$empty_fix; \
+	  if test $$# -gt 0; then \
+	    $(ETAGS) $(ETAGSFLAGS) $(AM_ETAGSFLAGS) $(ETAGS_ARGS) \
+	      "$$@" $$unique; \
+	  else \
+	    $(ETAGS) $(ETAGSFLAGS) $(AM_ETAGSFLAGS) $(ETAGS_ARGS) \
+	      $$unique; \
+	  fi; \
+	fi
+ctags: ctags-recursive
+
+CTAGS: ctags
+ctags-am: $(TAGS_DEPENDENCIES) $(am__tagged_files)
+	$(am__define_uniq_tagged_files); \
+	test -z "$(CTAGS_ARGS)$$unique" \
+	  || $(CTAGS) $(CTAGSFLAGS) $(AM_CTAGSFLAGS) $(CTAGS_ARGS) \
+	     $$unique
+
+GTAGS:
+	here=`$(am__cd) $(top_builddir) && pwd` \
+	  && $(am__cd) $(top_srcdir) \
+	  && gtags -i $(GTAGS_ARGS) "$$here"
+cscopelist: cscopelist-recursive
+
+cscopelist-am: $(am__tagged_files)
+	list='$(am__tagged_files)'; \
+	case "$(srcdir)" in \
+	  [\\/]* | ?:[\\/]*) sdir="$(srcdir)" ;; \
+	  *) sdir=$(subdir)/$(srcdir) ;; \
+	esac; \
+	for i in $$list; do \
+	  if test -f "$$i"; then \
+	    echo "$(subdir)/$$i"; \
+	  else \
+	    echo "$$sdir/$$i"; \
+	  fi; \
+	done >> $(top_builddir)/cscope.files
+
+distclean-tags:
+	-rm -f TAGS ID GTAGS GRTAGS GSYMS GPATH tags
+
+distdir: $(BUILT_SOURCES)
+	$(MAKE) $(AM_MAKEFLAGS) distdir-am
+
+distdir-am: $(DISTFILES)
+	@srcdirstrip=`echo "$(srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
+	topsrcdirstrip=`echo "$(top_srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
+	list='$(DISTFILES)'; \
+	  dist_files=`for file in $$list; do echo $$file; done | \
+	  sed -e "s|^$$srcdirstrip/||;t" \
+	      -e "s|^$$topsrcdirstrip/|$(top_builddir)/|;t"`; \
+	case $$dist_files in \
+	  */*) $(MKDIR_P) `echo "$$dist_files" | \
+			   sed '/\//!d;s|^|$(distdir)/|;s,/[^/]*$$,,' | \
+			   sort -u` ;; \
+	esac; \
+	for file in $$dist_files; do \
+	  if test -f $$file || test -d $$file; then d=.; else d=$(srcdir); fi; \
+	  if test -d $$d/$$file; then \
+	    dir=`echo "/$$file" | sed -e 's,/[^/]*$$,,'`; \
+	    if test -d "$(distdir)/$$file"; then \
+	      find "$(distdir)/$$file" -type d ! -perm -700 -exec chmod u+rwx {} \;; \
+	    fi; \
+	    if test -d $(srcdir)/$$file && test $$d != $(srcdir); then \
+	      cp -fpR $(srcdir)/$$file "$(distdir)$$dir" || exit 1; \
+	      find "$(distdir)/$$file" -type d ! -perm -700 -exec chmod u+rwx {} \;; \
+	    fi; \
+	    cp -fpR $$d/$$file "$(distdir)$$dir" || exit 1; \
+	  else \
+	    test -f "$(distdir)/$$file" \
+	    || cp -p $$d/$$file "$(distdir)/$$file" \
+	    || exit 1; \
+	  fi; \
+	done
+	@list='$(DIST_SUBDIRS)'; for subdir in $$list; do \
+	  if test "$$subdir" = .; then :; else \
+	    $(am__make_dryrun) \
+	      || test -d "$(distdir)/$$subdir" \
+	      || $(MKDIR_P) "$(distdir)/$$subdir" \
+	      || exit 1; \
+	    dir1=$$subdir; dir2="$(distdir)/$$subdir"; \
+	    $(am__relativize); \
+	    new_distdir=$$reldir; \
+	    dir1=$$subdir; dir2="$(top_distdir)"; \
+	    $(am__relativize); \
+	    new_top_distdir=$$reldir; \
+	    echo " (cd $$subdir && $(MAKE) $(AM_MAKEFLAGS) top_distdir="$$new_top_distdir" distdir="$$new_distdir" \\"; \
+	    echo "     am__remove_distdir=: am__skip_length_check=: am__skip_mode_fix=: distdir)"; \
+	    ($(am__cd) $$subdir && \
+	      $(MAKE) $(AM_MAKEFLAGS) \
+	        top_distdir="$$new_top_distdir" \
+	        distdir="$$new_distdir" \
+		am__remove_distdir=: \
+		am__skip_length_check=: \
+		am__skip_mode_fix=: \
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+	      || exit 1; \
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+check-am: all-am
+check: check-recursive
+all-am: Makefile $(SCRIPTS) $(DATA)
+installdirs: installdirs-recursive
+installdirs-am:
+	for dir in "$(DESTDIR)$(pgsqldir)" "$(DESTDIR)$(pgsqldir)"; do \
+	  test -z "$$dir" || $(MKDIR_P) "$$dir"; \
+	done
+install: install-recursive
+install-exec: install-exec-recursive
+install-data: install-data-recursive
+uninstall: uninstall-recursive
+
+install-am: all-am
+	@$(MAKE) $(AM_MAKEFLAGS) install-exec-am install-data-am
+
+installcheck: installcheck-recursive
+install-strip:
+	if test -z '$(STRIP)'; then \
+	  $(MAKE) $(AM_MAKEFLAGS) INSTALL_PROGRAM="$(INSTALL_STRIP_PROGRAM)" \
+	    install_sh_PROGRAM="$(INSTALL_STRIP_PROGRAM)" INSTALL_STRIP_FLAG=-s \
+	      install; \
+	else \
+	  $(MAKE) $(AM_MAKEFLAGS) INSTALL_PROGRAM="$(INSTALL_STRIP_PROGRAM)" \
+	    install_sh_PROGRAM="$(INSTALL_STRIP_PROGRAM)" INSTALL_STRIP_FLAG=-s \
+	    "INSTALL_PROGRAM_ENV=STRIPPROG='$(STRIP)'" install; \
+	fi
+mostlyclean-generic:
+
+clean-generic:
+
+distclean-generic:
+	-test -z "$(CONFIG_CLEAN_FILES)" || rm -f $(CONFIG_CLEAN_FILES)
+	-test . = "$(srcdir)" || test -z "$(CONFIG_CLEAN_VPATH_FILES)" || rm -f $(CONFIG_CLEAN_VPATH_FILES)
+	-test -z "$(DISTCLEANFILES)" || rm -f $(DISTCLEANFILES)
+
+maintainer-clean-generic:
+	@echo "This command is intended for maintainers to use"
+	@echo "it deletes files that may require special tools to rebuild."
+clean: clean-recursive
+
+clean-am: clean-generic clean-libtool mostlyclean-am
+
+distclean: distclean-recursive
+	-rm -f Makefile
+distclean-am: clean-am distclean-generic distclean-tags
+
+dvi: dvi-recursive
+
+dvi-am:
+
+html: html-recursive
+
+html-am:
+
+info: info-recursive
+
+info-am:
+
+install-data-am: install-pgsqlDATA install-pgsqlSCRIPTS
+
+install-dvi: install-dvi-recursive
+
+install-dvi-am:
+
+install-exec-am:
+
+install-html: install-html-recursive
+
+install-html-am:
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+install-info: install-info-recursive
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+install-info-am:
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+install-pdf: install-pdf-recursive
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+install-pdf-am:
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+install-ps: install-ps-recursive
+
+install-ps-am:
+
+installcheck-am:
+
+maintainer-clean: maintainer-clean-recursive
+	-rm -f Makefile
+maintainer-clean-am: distclean-am maintainer-clean-generic
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+mostlyclean: mostlyclean-recursive
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+mostlyclean-am: mostlyclean-generic mostlyclean-libtool
+
+pdf: pdf-recursive
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+ps: ps-recursive
+
+ps-am:
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+uninstall-am: uninstall-pgsqlDATA uninstall-pgsqlSCRIPTS
+
+.MAKE: $(am__recursive_targets) install-am install-strip
+
+.PHONY: $(am__recursive_targets) CTAGS GTAGS TAGS all all-am check \
+	check-am clean clean-generic clean-libtool cscopelist-am ctags \
+	ctags-am distclean distclean-generic distclean-libtool \
+	distclean-tags distdir dvi dvi-am html html-am info info-am \
+	install install-am install-data install-data-am install-dvi \
+	install-dvi-am install-exec install-exec-am install-html \
+	install-html-am install-info install-info-am install-man \
+	install-pdf install-pdf-am install-pgsqlDATA \
+	install-pgsqlSCRIPTS install-ps install-ps-am install-strip \
+	installcheck installcheck-am installdirs installdirs-am \
+	maintainer-clean maintainer-clean-generic mostlyclean \
+	mostlyclean-generic mostlyclean-libtool pdf pdf-am ps ps-am \
+	tags tags-am uninstall uninstall-am uninstall-pgsqlDATA \
+	uninstall-pgsqlSCRIPTS
+
+.PRECIOUS: Makefile
+
+
+# Tell versions [3.59,3.63) of GNU make to not export all variables.
+# Otherwise a system limit (for SysV at least) may be exceeded.
+.NOEXPORT:
diff --git a/src/share/database/scripts/pgsql/dhcpdb_create.pgsql b/src/share/database/scripts/pgsql/dhcpdb_create.pgsql
new file mode 100644
index 0000000..93708a1
--- /dev/null
+++ b/src/share/database/scripts/pgsql/dhcpdb_create.pgsql
@@ -0,0 +1,6296 @@
+-- Copyright (C) 2012-2023 Internet Systems Consortium, Inc. ("ISC")
+
+-- This Source Code Form is subject to the terms of the Mozilla Public
+-- License, v. 2.0. If a copy of the MPL was not distributed with this
+-- file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+-- This is the Kea DHCP schema specification for PostgreSQL.
+
+-- The schema is reasonably portable (with the exception of some field types
+-- specification, which are PostgreSQL-specific).  Minor changes might be needed
+-- for other databases.
+
+-- To create the schema, either type the command:
+
+-- psql -U <user> -W <password> <database> < dhcpdb_create.pgsql
+
+-- ... at the command prompt, or log in to the PostgreSQL database and at the "postgres=#"
+-- prompt, issue the command:
+
+-- @dhcpdb_create.pgsql
+
+-- Start a single transaction for the entire script.
+START TRANSACTION;
+
+-- Holds the IPv4 leases.
+CREATE TABLE lease4 (
+    address BIGINT PRIMARY KEY NOT NULL,        -- IPv4 address
+    hwaddr BYTEA,                               -- Hardware address
+    client_id BYTEA,                            -- Client ID
+    valid_lifetime BIGINT,                      -- Length of the lease (seconds)
+    expire TIMESTAMP WITH TIME ZONE,            -- Expiration time of the lease
+    subnet_id BIGINT,                           -- Subnet identification
+    fqdn_fwd BOOLEAN,                           -- Has forward DNS update been performed by a server
+    fqdn_rev BOOLEAN,                           -- Has reverse DNS update been performed by a server
+    hostname VARCHAR(255)                       -- The FQDN of the client
+    );
+
+-- Create search indexes for lease4 table
+-- index by hwaddr and subnet_id
+CREATE INDEX lease4_by_hwaddr_subnet_id ON lease4 (hwaddr, subnet_id);
+
+-- index by client_id and subnet_id
+CREATE INDEX lease4_by_client_id_subnet_id ON lease4 (client_id, subnet_id);
+
+-- Holds the IPv6 leases.
+-- N.B. The use of a VARCHAR for the address is temporary for development:
+-- it will eventually be replaced by BINARY(16).
+CREATE TABLE lease6 (
+    address VARCHAR(39) PRIMARY KEY NOT NULL,   -- IPv6 address
+    duid BYTEA,                                 -- DUID
+    valid_lifetime BIGINT,                      -- Length of the lease (seconds)
+    expire TIMESTAMP WITH TIME ZONE,            -- Expiration time of the lease
+    subnet_id BIGINT,                           -- Subnet identification
+    pref_lifetime BIGINT,                       -- Preferred lifetime
+    lease_type SMALLINT,                        -- Lease type (see lease6_types
+                                                --    table for possible values)
+    iaid INT,                                   -- See Section 12 of RFC 8415
+    prefix_len SMALLINT,                        -- For IA_PD only
+    fqdn_fwd BOOLEAN,                           -- Has forward DNS update been performed by a server
+    fqdn_rev BOOLEAN,                           -- Has reverse DNS update been performed by a server
+    hostname VARCHAR(255)                       -- The FQDN of the client
+    );
+
+-- Create search indexes for lease6 table
+-- index by iaid, subnet_id, and duid
+CREATE INDEX lease6_by_iaid_subnet_id_duid ON lease6 (iaid, subnet_id, duid);
+
+-- ... and a definition of lease6 types.  This table is a convenience for
+-- users of the database - if they want to view the lease table and use the
+-- type names, they can join this table with the lease6 table
+CREATE TABLE lease6_types (
+    lease_type SMALLINT PRIMARY KEY NOT NULL,   -- Lease type code.
+    name VARCHAR(5)                             -- Name of the lease type
+    );
+
+INSERT INTO lease6_types VALUES (0, 'IA_NA');   -- Non-temporary v6 addresses
+INSERT INTO lease6_types VALUES (1, 'IA_TA');   -- Temporary v6 addresses
+INSERT INTO lease6_types VALUES (2, 'IA_PD');   -- Prefix delegations
+
+-- Finally, the version of the schema.  We start at 0.1 during development.
+-- This table is only modified during schema upgrades.  For historical reasons
+-- (related to the names of the columns in the BIND 10 DNS database file), the
+-- first column is called "version" and not "major".
+CREATE TABLE schema_version (
+    version INT PRIMARY KEY NOT NULL,       -- Major version number
+    minor INT                               -- Minor version number
+    );
+
+INSERT INTO schema_version VALUES (1, 0);
+
+-- This line starts the schema upgrade to version 2.0.
+
+-- Add state column to the lease4 table.
+ALTER TABLE lease4
+    ADD COLUMN state INT8 DEFAULT 0;
+
+-- Add state column to the lease6 table.
+ALTER TABLE lease6
+    ADD COLUMN state INT8 DEFAULT 0;
+
+-- Create indexes for querying leases in a given state and segregated
+-- by the expiration time. One of the applications is to retrieve all
+-- expired leases. However, these indexes can be also used to retrieve
+-- leases in a given state regardless of the expiration time.
+CREATE INDEX lease4_by_state_expire ON lease4 (state ASC, expire ASC);
+CREATE INDEX lease6_by_state_expire ON lease6 (state ASC, expire ASC);
+
+-- Create table holding mapping of the lease states to their names.
+-- This is not used in queries from the DHCP server but rather in
+-- direct queries from the lease database management tools.
+CREATE TABLE lease_state (
+    state INT8 PRIMARY KEY NOT NULL,
+    name VARCHAR(64) NOT NULL);
+
+-- Insert currently defined state names.
+INSERT INTO lease_state VALUES (0, 'default');
+INSERT INTO lease_state VALUES (1, 'declined');
+INSERT INTO lease_state VALUES (2, 'expired-reclaimed');
+
+-- Add a constraint that any state value added to the lease4 must
+-- map to a value in the lease_state table.
+ALTER TABLE lease4
+    ADD CONSTRAINT fk_lease4_state FOREIGN KEY (state)
+    REFERENCES lease_state (state);
+
+-- Add a constraint that any state value added to the lease6 must
+-- map to a value in the lease_state table.
+ALTER TABLE lease6
+    ADD CONSTRAINT fk_lease6_state FOREIGN KEY (state)
+    REFERENCES lease_state (state);
+
+-- Add a constraint that lease type in the lease6 table must map
+-- to a lease type defined in the lease6_types table.
+ALTER TABLE lease6
+    ADD CONSTRAINT fk_lease6_type FOREIGN KEY (lease_type)
+    REFERENCES lease6_types (lease_type);
+
+--
+--  FUNCTION that returns a result set containing the column names for lease4 dumps.
+DROP FUNCTION IF EXISTS lease4DumpHeader();
+CREATE OR REPLACE FUNCTION lease4DumpHeader() RETURNS text AS  $$
+    select cast('address,hwaddr,client_id,valid_lifetime,expire,subnet_id,fqdn_fwd,fqdn_rev,hostname,state' as text) as result;
+$$ LANGUAGE SQL;
+--
+
+--
+--  FUNCTION that returns a result set containing the data for lease4 dumps.
+DROP FUNCTION IF EXISTS lease4DumpData();
+CREATE OR REPLACE FUNCTION lease4DumpData() RETURNS
+    table (address inet,
+           hwaddr text,
+           client_id text,
+           valid_lifetime bigint,
+           expire TIMESTAMP WITH TIME ZONE,
+           subnet_id bigint,
+           fqdn_fwd int,
+           fqdn_rev int,
+           hostname text,
+           state text
+    ) as $$
+    SELECT ('0.0.0.0'::inet + l.address),
+            encode(l.hwaddr,'hex'),
+            encode(l.client_id,'hex'),
+            l.valid_lifetime,
+            l.expire,
+            l.subnet_id,
+            l.fqdn_fwd::int,
+            l.fqdn_rev::int,
+            l.hostname,
+            s.name
+    FROM lease4 l
+         left outer join lease_state s on (l.state = s.state);
+$$ LANGUAGE SQL;
+--
+
+--
+--  FUNCTION that returns a result set containing the column names for lease6 dumps.
+DROP FUNCTION IF EXISTS lease6DumpHeader();
+CREATE OR REPLACE FUNCTION lease6DumpHeader() RETURNS text AS  $$
+    select cast('address,duid,valid_lifetime,expire,subnet_id,pref_lifetime,lease_type,iaid,prefix_len,fqdn_fwd,fqdn_rev,hostname,state' as text) as result;
+$$ LANGUAGE SQL;
+--
+
+--
+--  FUNCTION that returns a result set containing the data for lease6 dumps.
+DROP FUNCTION IF EXISTS lease6DumpData();
+CREATE OR REPLACE FUNCTION lease6DumpData() RETURNS
+    TABLE (
+           address text,
+           duid text,
+           valid_lifetime bigint,
+           expire TIMESTAMP WITH TIME ZONE,
+           subnet_id bigint,
+           pref_lifetime bigint,
+           name text,
+           iaid integer,
+           prefix_len smallint,
+           fqdn_fwd int,
+           fqdn_rev int,
+           hostname text,
+           state text
+    ) AS $$
+    SELECT (l.address,
+            encode(l.duid,'hex'),
+            l.valid_lifetime,
+            l.expire,
+            l.subnet_id,
+            l.pref_lifetime,
+            t.name,
+            l.iaid,
+            l.prefix_len,
+            l.fqdn_fwd::int,
+            l.fqdn_rev::int,
+            l.hostname,
+            s.name)
+     FROM lease6 l
+         left outer join lease6_types t on (l.lease_type = t.lease_type)
+         left outer join lease_state s on (l.state = s.state);
+$$ LANGUAGE SQL;
+--
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '2', minor = '0';
+
+-- This line concludes the schema upgrade to version 2.0.
+
+-- This line starts the schema upgrade to version 3.0.
+
+--
+-- Table structure for table host_identifier_type.
+--
+
+CREATE TABLE host_identifier_type (
+  type SMALLINT PRIMARY KEY NOT NULL,
+  name VARCHAR(32) DEFAULT NULL
+);
+
+INSERT INTO host_identifier_type VALUES (0, 'hw-address');
+INSERT INTO host_identifier_type VALUES (1, 'duid');
+INSERT INTO host_identifier_type VALUES (2, 'circuit-id');
+INSERT INTO host_identifier_type VALUES (3, 'client-id');
+
+--
+-- Table structure for table dhcp_option_scope.
+--
+
+CREATE TABLE dhcp_option_scope (
+  scope_id SMALLINT PRIMARY KEY NOT NULL,
+  scope_name VARCHAR(32) DEFAULT NULL
+);
+
+INSERT INTO dhcp_option_scope VALUES (0, 'global');
+INSERT INTO dhcp_option_scope VALUES (1, 'subnet');
+INSERT INTO dhcp_option_scope VALUES (2, 'client-class');
+INSERT INTO dhcp_option_scope VALUES (3, 'host');
+
+--
+-- Table structure for table hosts.
+--
+-- Primary key and unique constraints automatically create indexes,
+-- foreign key constraints do not.
+CREATE TABLE hosts (
+  host_id SERIAL PRIMARY KEY NOT NULL,
+  dhcp_identifier BYTEA NOT NULL,
+  dhcp_identifier_type SMALLINT NOT NULL,
+  dhcp4_subnet_id INT DEFAULT NULL,
+  dhcp6_subnet_id INT DEFAULT NULL,
+  ipv4_address BIGINT DEFAULT NULL,
+  hostname VARCHAR(255) DEFAULT NULL,
+  dhcp4_client_classes VARCHAR(255) DEFAULT NULL,
+  dhcp6_client_classes VARCHAR(255) DEFAULT NULL,
+  CONSTRAINT key_dhcp4_ipv4_address_subnet_id UNIQUE (ipv4_address, dhcp4_subnet_id),
+  CONSTRAINT key_dhcp4_identifier_subnet_id UNIQUE (dhcp_identifier, dhcp_identifier_type, dhcp4_subnet_id),
+  CONSTRAINT key_dhcp6_identifier_subnet_id UNIQUE (dhcp_identifier, dhcp_identifier_type, dhcp6_subnet_id),
+  CONSTRAINT fk_host_identifier_type FOREIGN KEY (dhcp_identifier_type) REFERENCES host_identifier_type (type)
+  ON DELETE CASCADE
+);
+
+CREATE INDEX fk_host_identifier_type ON hosts (dhcp_identifier_type);
+
+--
+-- Table structure for table dhcp4_options.
+--
+
+CREATE TABLE dhcp4_options (
+  option_id SERIAL PRIMARY KEY NOT NULL,
+  code SMALLINT NOT NULL,
+  value BYTEA,
+  formatted_value TEXT,
+  space VARCHAR(128) DEFAULT NULL,
+  persistent BOOLEAN NOT NULL DEFAULT 'f',
+  dhcp_client_class VARCHAR(128) DEFAULT NULL,
+  dhcp4_subnet_id BIGINT DEFAULT NULL,
+  host_id INT DEFAULT NULL,
+  scope_id SMALLINT NOT NULL,
+  CONSTRAINT fk_options_host1 FOREIGN KEY (host_id) REFERENCES hosts (host_id) ON DELETE CASCADE,
+  CONSTRAINT fk_dhcp4_option_scode FOREIGN KEY (scope_id) REFERENCES dhcp_option_scope (scope_id) ON DELETE CASCADE
+);
+
+CREATE INDEX fk_dhcp4_options_host1_idx ON dhcp4_options (host_id);
+CREATE INDEX fk_dhcp4_options_scope_idx ON dhcp4_options (scope_id);
+
+--
+-- Table structure for table dhcp6_options.
+--
+
+CREATE TABLE dhcp6_options (
+  option_id SERIAL PRIMARY KEY NOT NULL,
+  code INT NOT NULL,
+  value BYTEA,
+  formatted_value TEXT,
+  space VARCHAR(128) DEFAULT NULL,
+  persistent BOOLEAN NOT NULL DEFAULT 'f',
+  dhcp_client_class VARCHAR(128) DEFAULT NULL,
+  dhcp6_subnet_id BIGINT DEFAULT NULL,
+  host_id INT DEFAULT NULL,
+  scope_id SMALLINT NOT NULL,
+  CONSTRAINT fk_options_host10 FOREIGN KEY (host_id) REFERENCES hosts (host_id) ON DELETE CASCADE,
+  CONSTRAINT fk_dhcp6_option_scode FOREIGN KEY (scope_id) REFERENCES dhcp_option_scope (scope_id) ON DELETE CASCADE
+);
+
+CREATE INDEX fk_dhcp6_options_host1_idx ON dhcp6_options (host_id);
+CREATE INDEX fk_dhcp6_options_scope_idx ON dhcp6_options (scope_id);
+
+--
+-- Table structure for table ipv6_reservations.
+--
+
+CREATE TABLE ipv6_reservations (
+  reservation_id SERIAL PRIMARY KEY NOT NULL,
+  address VARCHAR(39) NOT NULL,
+  prefix_len SMALLINT NOT NULL DEFAULT '128',
+  type SMALLINT NOT NULL DEFAULT '0',
+  dhcp6_iaid INT DEFAULT NULL,
+  host_id INT NOT NULL,
+  CONSTRAINT key_dhcp6_address_prefix_len UNIQUE (address, prefix_len),
+  CONSTRAINT fk_ipv6_reservations_host FOREIGN KEY (host_id) REFERENCES hosts (host_id) ON DELETE CASCADE
+);
+
+CREATE INDEX fk_ipv6_reservations_host_idx ON ipv6_reservations (host_id);
+
+--
+-- Table structure for table lease_hwaddr_source.
+--
+
+CREATE TABLE lease_hwaddr_source (
+  hwaddr_source INT PRIMARY KEY NOT NULL,
+  name VARCHAR(40) DEFAULT NULL
+);
+
+-- In the event hardware address cannot be determined, we need to satisfy
+-- foreign key constraint between lease6 and lease_hardware_source.
+INSERT INTO lease_hwaddr_source VALUES (0, 'HWADDR_SOURCE_UNKNOWN');
+
+-- Hardware address obtained from raw sockets.
+INSERT INTO lease_hwaddr_source VALUES (1, 'HWADDR_SOURCE_RAW');
+
+-- Hardware address converted from IPv6 link-local address with EUI-64.
+INSERT INTO lease_hwaddr_source VALUES (2, 'HWADDR_SOURCE_IPV6_LINK_LOCAL');
+
+-- Hardware address extracted from client-id (duid).
+INSERT INTO lease_hwaddr_source VALUES (4, 'HWADDR_SOURCE_DUID');
+
+-- Hardware address extracted from client address relay option (RFC6939).
+INSERT INTO lease_hwaddr_source VALUES (8, 'HWADDR_SOURCE_CLIENT_ADDR_RELAY_OPTION');
+
+-- Hardware address extracted from remote-id option (RFC4649).
+INSERT INTO lease_hwaddr_source VALUES (16, 'HWADDR_SOURCE_REMOTE_ID');
+
+-- Hardware address extracted from subscriber-id option (RFC4580).
+INSERT INTO lease_hwaddr_source VALUES (32, 'HWADDR_SOURCE_SUBSCRIBER_ID');
+
+-- Hardware address extracted from docsis options.
+INSERT INTO lease_hwaddr_source VALUES (64, 'HWADDR_SOURCE_DOCSIS_CMTS');
+
+INSERT INTO lease_hwaddr_source VALUES (128, 'HWADDR_SOURCE_DOCSIS_MODEM');
+
+-- Adding ORDER BY clause to sort by lease address.
+--
+--  FUNCTION that returns a result set containing the data for lease4 dumps.
+DROP FUNCTION IF EXISTS lease4DumpData();
+CREATE OR REPLACE FUNCTION lease4DumpData() RETURNS
+    table (address inet,
+           hwaddr text,
+           client_id text,
+           valid_lifetime bigint,
+           expire TIMESTAMP WITH TIME ZONE,
+           subnet_id bigint,
+           fqdn_fwd int,
+           fqdn_rev int,
+           hostname text,
+           state text
+    ) as $$
+    SELECT ('0.0.0.0'::inet + l.address),
+            encode(l.hwaddr,'hex'),
+            encode(l.client_id,'hex'),
+            l.valid_lifetime,
+            l.expire,
+            l.subnet_id,
+            l.fqdn_fwd::int,
+            l.fqdn_rev::int,
+            l.hostname,
+            s.name
+    FROM lease4 l
+         left outer join lease_state s on (l.state = s.state)
+    ORDER BY l.address;
+$$ LANGUAGE SQL;
+--
+
+-- Add new columns to lease6.
+ALTER TABLE lease6
+  ADD COLUMN hwaddr BYTEA DEFAULT NULL,
+  ADD COLUMN hwtype SMALLINT DEFAULT NULL,
+  ADD COLUMN hwaddr_source SMALLINT DEFAULT NULL;
+
+--
+--  FUNCTION that returns a result set containing the column names for lease6 dumps.
+DROP FUNCTION IF EXISTS lease6DumpHeader();
+CREATE OR REPLACE FUNCTION lease6DumpHeader() RETURNS text AS  $$
+    select cast('address,duid,valid_lifetime,expire,subnet_id,pref_lifetime,lease_type,iaid,prefix_len,fqdn_fwd,fqdn_rev,hostname,state,hwaddr,hwtype,hwaddr_source' as text) as result;
+$$ LANGUAGE SQL;
+--
+
+--
+--  FUNCTION that returns a result set containing the data for lease6 dumps.
+DROP FUNCTION IF EXISTS lease6DumpData();
+CREATE OR REPLACE FUNCTION lease6DumpData() RETURNS
+    TABLE (
+           address text,
+           duid text,
+           valid_lifetime bigint,
+           expire TIMESTAMP WITH TIME ZONE,
+           subnet_id bigint,
+           pref_lifetime bigint,
+           name text,
+           iaid integer,
+           prefix_len smallint,
+           fqdn_fwd int,
+           fqdn_rev int,
+           hostname text,
+           state text,
+           hwaddr text,
+           hwtype smallint,
+           hwaddr_source text
+    ) AS $$
+    SELECT (l.address,
+            encode(l.duid,'hex'),
+            l.valid_lifetime,
+            l.expire,
+            l.subnet_id,
+            l.pref_lifetime,
+            t.name,
+            l.iaid,
+            l.prefix_len,
+            l.fqdn_fwd::int,
+            l.fqdn_rev::int,
+            l.hostname,
+            s.name,
+            encode(l.hwaddr,'hex'),
+            l.hwtype,
+            h.name
+     )
+     FROM lease6 l
+         left outer join lease6_types t on (l.lease_type = t.lease_type)
+         left outer join lease_state s on (l.state = s.state)
+         left outer join lease_hwaddr_source h on (l.hwaddr_source = h.hwaddr_source)
+     ORDER BY l.address;
+$$ LANGUAGE SQL;
+
+-- Add columns holding reservations for siaddr, sname and file fields
+-- carried within DHCPv4 message.
+ALTER TABLE hosts ADD COLUMN dhcp4_next_server BIGINT DEFAULT NULL;
+ALTER TABLE hosts ADD COLUMN dhcp4_server_hostname VARCHAR(64) DEFAULT NULL;
+ALTER TABLE hosts ADD COLUMN dhcp4_boot_file_name VARCHAR(128) DEFAULT NULL;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '3', minor = '0';
+
+-- This line concludes the schema upgrade to version 3.0.
+
+-- This line starts the schema upgrade to version 3.1.
+
+-- This is a placeholder for the changes between 3.0 and 3.1. We have added a
+-- missing 'client-id' host reservation type entry that had been accidentally
+-- omitted when the 2.0 -> 3.0 upgrade script was created.
+-- Also, new flexible identifier has been added.
+INSERT INTO host_identifier_type VALUES (4, 'flex-id');
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '3', minor = '1';
+
+-- This line concludes the schema upgrade to version 3.1.
+
+-- This line starts the schema upgrade to version 3.2.
+
+-- Remove constraints which perform too restrictive checks on the inserted
+-- host reservations. We want to be able to insert host reservations which
+-- include no specific IPv4 address or those that have repeating subnet
+-- identifiers, e.g. IPv4 reservations would typically include 0 (or null)
+-- IPv6 subnet identifiers.
+ALTER TABLE hosts DROP CONSTRAINT key_dhcp4_ipv4_address_subnet_id;
+ALTER TABLE hosts DROP CONSTRAINT key_dhcp4_identifier_subnet_id;
+ALTER TABLE hosts DROP CONSTRAINT key_dhcp6_identifier_subnet_id;
+
+-- Create partial indexes instead of the constraints that we have removed.
+
+-- IPv4 address/IPv4 subnet identifier pair is unique if subnet identifier is
+-- not null and not 0.
+CREATE UNIQUE INDEX key_dhcp4_ipv4_address_subnet_id ON hosts
+       (ipv4_address ASC, dhcp4_subnet_id ASC)
+    WHERE ipv4_address IS NOT NULL AND ipv4_address <> 0;
+
+-- Client identifier is unique within an IPv4 subnet when subnet identifier is
+-- not null and not 0.
+CREATE UNIQUE INDEX key_dhcp4_identifier_subnet_id ON hosts
+        (dhcp_identifier ASC, dhcp_identifier_type ASC, dhcp4_subnet_id ASC)
+    WHERE (dhcp4_subnet_id IS NOT NULL AND dhcp4_subnet_id <> 0);
+
+-- Client identifier is unique within an IPv6 subnet when subnet identifier is
+-- not null and not 0.
+CREATE UNIQUE INDEX key_dhcp6_identifier_subnet_id ON hosts
+        (dhcp_identifier ASC, dhcp_identifier_type ASC, dhcp6_subnet_id ASC)
+    WHERE (dhcp6_subnet_id IS NOT NULL AND dhcp6_subnet_id <> 0);
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '3', minor = '2';
+
+-- This line concludes the schema upgrade to version 3.2.
+
+-- This line starts the schema upgrade to version 3.3.
+
+-- Change subnet ID columns type to BIGINT to match lease4/6 tables
+ALTER TABLE hosts ALTER COLUMN dhcp4_subnet_id TYPE BIGINT;
+ALTER TABLE hosts ALTER COLUMN dhcp6_subnet_id TYPE BIGINT;
+
+ALTER TABLE dhcp4_options ALTER COLUMN dhcp4_subnet_id TYPE BIGINT;
+ALTER TABLE dhcp6_options ALTER COLUMN dhcp6_subnet_id TYPE BIGINT;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '3', minor = '3';
+
+-- This line concludes the schema upgrade to version 3.3.
+
+-- This line starts the schema upgrade to version 4.0.
+
+-- Add a column holding hosts for user context.
+ALTER TABLE hosts ADD COLUMN user_context TEXT;
+
+-- Add a column holding DHCP options for user context.
+ALTER TABLE dhcp4_options ADD COLUMN user_context TEXT;
+ALTER TABLE dhcp6_options ADD COLUMN user_context TEXT;
+
+-- Create index for searching leases by subnet identifier.
+CREATE INDEX lease4_by_subnet_id ON lease4 (subnet_id);
+
+-- Create for searching leases by subnet identifier and lease type.
+CREATE INDEX lease6_by_subnet_id_lease_type ON lease6 (subnet_id, lease_type);
+
+-- The index by iaid_subnet_id_duid is not the best choice because there are
+-- cases when we don't specify subnet identifier while searching leases. The
+-- index will be universal if the subnet_id is the right most column in the
+-- index.
+DROP INDEX lease6_by_iaid_subnet_id_duid;
+CREATE INDEX lease6_by_duid_iaid_subnet_id ON lease6 (duid, iaid, subnet_id);
+
+-- Create v4 lease statistics table
+CREATE TABLE lease4_stat (
+    subnet_id BIGINT NOT NULL,
+    state INT8 NOT NULL,
+    leases BIGINT,
+    PRIMARY KEY (subnet_id, state)
+);
+
+--
+-- Create v4 insert trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease4_insert() RETURNS trigger AS $stat_lease4_insert$
+BEGIN
+    IF NEW.state < 2 THEN
+        UPDATE lease4_stat
+            SET leases = leases + 1
+            WHERE subnet_id = NEW.subnet_id AND state = NEW.state;
+
+        IF NOT FOUND THEN
+            INSERT INTO lease4_stat VALUES (new.subnet_id, new.state, 1);
+        END IF;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+$stat_lease4_insert$ LANGUAGE plpgsql;
+
+-- Create v4 insert trigger procedure
+CREATE TRIGGER stat_lease4_insert
+AFTER INSERT ON lease4
+    FOR EACH ROW EXECUTE PROCEDURE proc_stat_lease4_insert();
+
+--
+-- Create v4 update trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease4_update() RETURNS trigger AS $stat_lease4_update$
+BEGIN
+    IF OLD.state != NEW.state THEN
+        IF OLD.state < 2 THEN
+            -- Decrement the old state count if record exists
+            UPDATE lease4_stat SET leases = leases - 1
+            WHERE subnet_id = OLD.subnet_id AND state = OLD.state;
+        END IF;
+
+        IF NEW.state < 2 THEN
+            -- Increment the new state count if record exists
+            UPDATE lease4_stat SET leases = leases + 1
+            WHERE subnet_id = NEW.subnet_id AND state = NEW.state;
+
+            -- Insert new state record if it does not exist
+            IF NOT FOUND THEN
+                INSERT INTO lease4_stat VALUES (NEW.subnet_id, NEW.state, 1);
+            END IF;
+        END IF;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+$stat_lease4_update$ LANGUAGE plpgsql;
+
+-- Create v4 update trigger
+CREATE TRIGGER stat_lease4_update
+AFTER UPDATE ON lease4
+    FOR EACH ROW EXECUTE PROCEDURE proc_stat_lease4_update();
+
+--
+-- Create the v4 delete trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease4_delete() RETURNS trigger AS $stat_lease4_delete$
+BEGIN
+    IF OLD.state < 2 THEN
+        -- Decrement the state count if record exists
+        UPDATE lease4_stat SET leases = leases - 1
+        WHERE subnet_id = OLD.subnet_id AND OLD.state = state;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+$stat_lease4_delete$ LANGUAGE plpgsql;
+
+-- Create the v4 delete trigger
+CREATE TRIGGER stat_lease4_delete
+AFTER DELETE ON lease4
+    FOR EACH ROW EXECUTE PROCEDURE proc_stat_lease4_delete();
+
+-- Create v6 lease statistics table
+CREATE TABLE lease6_stat (
+    subnet_id BIGINT NOT NULL,
+    lease_type SMALLINT NOT NULL,
+    state INT8 NOT NULL,
+    leases BIGINT,
+    PRIMARY KEY (subnet_id, lease_type, state)
+);
+
+--
+-- Create v6 insert trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease6_insert() RETURNS trigger AS $stat_lease6_insert$
+BEGIN
+    IF NEW.state < 2 THEN
+        UPDATE lease6_stat
+        SET leases = leases + 1
+        WHERE
+        subnet_id = NEW.subnet_id AND lease_type = NEW.lease_type
+        AND state = NEW.state;
+
+        IF NOT FOUND THEN
+            INSERT INTO lease6_stat
+            VALUES (NEW.subnet_id, NEW.lease_type, NEW.state, 1);
+        END IF;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+$stat_lease6_insert$ LANGUAGE plpgsql;
+
+-- Create v6 insert trigger procedure
+CREATE TRIGGER stat_lease6_insert
+AFTER INSERT ON lease6
+    FOR EACH ROW EXECUTE PROCEDURE proc_stat_lease6_insert();
+
+--
+-- Create v6 update trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease6_update() RETURNS trigger AS $stat_lease6_update$
+BEGIN
+    IF OLD.state != NEW.state THEN
+        IF OLD.state < 2 THEN
+            -- Decrement the old state count if record exists
+            UPDATE lease6_stat SET leases = leases - 1
+            WHERE subnet_id = OLD.subnet_id AND lease_type = OLD.lease_type
+            AND state = OLD.state;
+        END IF;
+
+        IF NEW.state < 2 THEN
+            -- Increment the new state count if record exists
+            UPDATE lease6_stat SET leases = leases + 1
+            WHERE subnet_id = NEW.subnet_id AND lease_type = NEW.lease_type
+            AND state = NEW.state;
+
+            -- Insert new state record if it does not exist
+            IF NOT FOUND THEN
+                INSERT INTO lease6_stat VALUES (NEW.subnet_id, NEW.lease_type, NEW.state, 1);
+            END IF;
+        END IF;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+$stat_lease6_update$ LANGUAGE plpgsql;
+
+-- Create v6 update trigger
+CREATE TRIGGER stat_lease6_update
+AFTER UPDATE ON lease6
+    FOR EACH ROW EXECUTE PROCEDURE proc_stat_lease6_update();
+
+--
+-- Create the v6 delete trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease6_delete() RETURNS trigger AS $stat_lease6_delete$
+BEGIN
+    IF OLD.state < 2 THEN
+        -- Decrement the state count if record exists
+        UPDATE lease6_stat SET leases = leases - 1
+        WHERE subnet_id = OLD.subnet_id AND lease_type = OLD.lease_type
+        AND OLD.state = state;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+$stat_lease6_delete$ LANGUAGE plpgsql;
+
+-- Create the v6 delete trigger
+CREATE TRIGGER stat_lease6_delete
+AFTER DELETE ON lease6
+    FOR EACH ROW EXECUTE PROCEDURE proc_stat_lease6_delete();
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '4', minor = '0';
+
+-- This line concludes the schema upgrade to version 4.0.
+
+-- This line starts the schema upgrade to version 5.0.
+
+-- Add a column holding leases for user context.
+ALTER TABLE lease4 ADD COLUMN user_context TEXT;
+ALTER TABLE lease6 ADD COLUMN user_context TEXT;
+
+--
+DROP FUNCTION IF EXISTS lease4DumpHeader();
+CREATE OR REPLACE FUNCTION lease4DumpHeader() RETURNS text AS  $$
+    select cast('address,hwaddr,client_id,valid_lifetime,expire,subnet_id,fqdn_fwd,fqdn_rev,hostname,state,user_context' as text) as result;
+$$ LANGUAGE SQL;
+--
+
+--
+DROP FUNCTION IF EXISTS lease4DumpData();
+CREATE OR REPLACE FUNCTION lease4DumpData() RETURNS
+    table (address inet,
+           hwaddr text,
+           client_id text,
+           valid_lifetime bigint,
+           expire TIMESTAMP WITH TIME ZONE,
+           subnet_id bigint,
+           fqdn_fwd int,
+           fqdn_rev int,
+           hostname text,
+           state text,
+           user_context text
+    ) as $$
+    SELECT ('0.0.0.0'::inet + l.address),
+            encode(l.hwaddr,'hex'),
+            encode(l.client_id,'hex'),
+            l.valid_lifetime,
+            l.expire,
+            l.subnet_id,
+            l.fqdn_fwd::int,
+            l.fqdn_rev::int,
+            l.hostname,
+            s.name,
+            l.user_context
+    FROM lease4 l
+         left outer join lease_state s on (l.state = s.state)
+    ORDER BY l.address;
+$$ LANGUAGE SQL;
+--
+
+--
+DROP FUNCTION IF EXISTS lease6DumpHeader();
+CREATE OR REPLACE FUNCTION lease6DumpHeader() RETURNS text AS  $$
+    select cast('address,duid,valid_lifetime,expire,subnet_id,pref_lifetime,lease_type,iaid,prefix_len,fqdn_fwd,fqdn_rev,hostname,state,hwaddr,hwtype,hwaddr_source,user_context' as text) as result;
+$$ LANGUAGE SQL;
+--
+
+--
+DROP FUNCTION IF EXISTS lease6DumpData();
+CREATE OR REPLACE FUNCTION lease6DumpData() RETURNS
+    TABLE (
+           address text,
+           duid text,
+           valid_lifetime bigint,
+           expire TIMESTAMP WITH TIME ZONE,
+           subnet_id bigint,
+           pref_lifetime bigint,
+           name text,
+           iaid integer,
+           prefix_len smallint,
+           fqdn_fwd int,
+           fqdn_rev int,
+           hostname text,
+           state text,
+           hwaddr text,
+           hwtype smallint,
+           hwaddr_source text,
+           user_context text
+    ) AS $$
+    SELECT (l.address,
+            encode(l.duid,'hex'),
+            l.valid_lifetime,
+            l.expire,
+            l.subnet_id,
+            l.pref_lifetime,
+            t.name,
+            l.iaid,
+            l.prefix_len,
+            l.fqdn_fwd::int,
+            l.fqdn_rev::int,
+            l.hostname,
+            s.name,
+            encode(l.hwaddr,'hex'),
+            l.hwtype,
+            h.name,
+            l.user_context
+
+     )
+     FROM lease6 l
+         left outer join lease6_types t on (l.lease_type = t.lease_type)
+         left outer join lease_state s on (l.state = s.state)
+         left outer join lease_hwaddr_source h on (l.hwaddr_source = h.hwaddr_source)
+     ORDER BY l.address;
+$$ LANGUAGE SQL;
+--
+
+-- Create logs table (logs table is used by forensic logging hook library)
+CREATE TABLE logs (
+    timestamp TIMESTAMP WITH TIME ZONE
+    DEFAULT CURRENT_TIMESTAMP,          -- creation timestamp
+    address VARCHAR(43) NULL,           -- address or prefix
+    log TEXT NOT NULL                   -- the log itself
+    );
+
+-- Create search indexes
+CREATE INDEX timestamp_id ON logs (timestamp);
+CREATE INDEX address_id ON logs (address);
+
+-- Create auth_key in hosts table for storing keys for DHCPv6 reconfigure.
+ALTER TABLE hosts ADD COLUMN auth_key  VARCHAR(16) DEFAULT NULL;
+
+-- Update the schema version number.
+UPDATE schema_version
+   SET version = '5', minor = '0';
+
+-- This line concludes the schema upgrade to version 5.0.
+
+-- This line starts the schema upgrade to version 5.1.
+
+-- Put the auth key in hexadecimal (double size but far more user friendly).
+ALTER TABLE hosts ALTER COLUMN auth_key TYPE VARCHAR(32);
+
+-- Update the schema version number.
+UPDATE schema_version
+   SET version = '5', minor = '1';
+
+-- This line concludes the schema upgrade to version 5.1.
+
+-- This line starts the schema upgrade to version 6.0.
+
+-- Create a lower case hostname index for hosts.
+CREATE INDEX hosts_by_hostname ON hosts (lower(hostname))
+WHERE hostname IS NOT NULL;
+
+-- Create a hostname index for lease4.
+CREATE INDEX lease4_by_hostname ON lease4 (lower(hostname))
+WHERE hostname IS NOT NULL;
+
+-- Create a hostname index for lease6.
+CREATE INDEX lease6_by_hostname ON lease6 (lower(hostname))
+WHERE hostname IS NOT NULL;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '6', minor = '0';
+
+-- This line concludes the schema upgrade to version 6.0.
+
+-- This line starts the schema upgrade to version 6.1.
+
+-- Fix v4 update trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease4_update() RETURNS trigger AS $stat_lease4_update$
+BEGIN
+    IF OLD.subnet_id != NEW.subnet_id OR OLD.state != NEW.state THEN
+        IF OLD.state < 2 THEN
+            -- Decrement the old state count if record exists
+            UPDATE lease4_stat SET leases = GREATEST(leases - 1, 0)
+            WHERE subnet_id = OLD.subnet_id AND state = OLD.state;
+        END IF;
+
+        IF NEW.state < 2 THEN
+            -- Increment the new state count if record exists
+            UPDATE lease4_stat SET leases = leases + 1
+            WHERE subnet_id = NEW.subnet_id AND state = NEW.state;
+
+            -- Insert new state record if it does not exist
+            IF NOT FOUND THEN
+                INSERT INTO lease4_stat VALUES (NEW.subnet_id, NEW.state, 1);
+            END IF;
+        END IF;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+$stat_lease4_update$ LANGUAGE plpgsql;
+
+--
+-- Fix the v4 delete trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease4_delete() RETURNS trigger AS $stat_lease4_delete$
+BEGIN
+    IF OLD.state < 2 THEN
+        -- Decrement the state count if record exists
+        UPDATE lease4_stat SET leases = GREATEST(leases - 1, 0)
+        WHERE subnet_id = OLD.subnet_id AND OLD.state = state;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+$stat_lease4_delete$ LANGUAGE plpgsql;
+
+--
+-- Fix v6 update trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease6_update() RETURNS trigger AS $stat_lease6_update$
+BEGIN
+    IF OLD.subnet_id != NEW.subnet_id OR
+       OLD.lease_type != NEW.lease_type OR
+       OLD.state != NEW.state THEN
+        IF OLD.state < 2 THEN
+            -- Decrement the old state count if record exists
+            UPDATE lease6_stat SET leases = GREATEST(leases - 1, 0)
+            WHERE subnet_id = OLD.subnet_id AND lease_type = OLD.lease_type
+            AND state = OLD.state;
+        END IF;
+
+        IF NEW.state < 2 THEN
+            -- Increment the new state count if record exists
+            UPDATE lease6_stat SET leases = leases + 1
+            WHERE subnet_id = NEW.subnet_id AND lease_type = NEW.lease_type
+            AND state = NEW.state;
+
+            -- Insert new state record if it does not exist
+            IF NOT FOUND THEN
+                INSERT INTO lease6_stat VALUES (NEW.subnet_id, NEW.lease_type, NEW.state, 1);
+            END IF;
+        END IF;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+$stat_lease6_update$ LANGUAGE plpgsql;
+
+--
+-- Fix the v6 delete trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease6_delete() RETURNS trigger AS $stat_lease6_delete$
+BEGIN
+    IF OLD.state < 2 THEN
+        -- Decrement the state count if record exists
+        UPDATE lease6_stat SET leases = GREATEST(leases - 1, 0)
+        WHERE subnet_id = OLD.subnet_id AND lease_type = OLD.lease_type
+        AND OLD.state = state;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+$stat_lease6_delete$ LANGUAGE plpgsql;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '6', minor = '1';
+
+-- This line concludes the schema upgrade to version 6.1.
+
+-- This line starts the schema upgrade to version 6.2.
+
+-- Starting from this version we allow specifying multiple IP reservations
+-- for the same address in certain DHCP configurations. The server may check
+-- uniqueness of the IP addresses on its own. This is no longer checked at
+-- the database level to facilitate the use cases when a single host may
+-- get the same reserved IP address via different interfaces.
+
+-- Replace the unique index with non-unique index so the queries for
+-- hosts by IPv4 address are still efficient.
+DROP INDEX IF EXISTS key_dhcp4_ipv4_address_subnet_id;
+CREATE INDEX key_dhcp4_ipv4_address_subnet_id
+    ON hosts (ipv4_address ASC, dhcp4_subnet_id ASC);
+
+-- Replace the unique index with non-unique index so the queries for
+-- hosts by IPv6 address are still efficient.
+ALTER TABLE ipv6_reservations DROP CONSTRAINT IF EXISTS key_dhcp6_address_prefix_len;
+CREATE INDEX key_dhcp6_address_prefix_len
+    ON ipv6_reservations (address ASC, prefix_len ASC);
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '6', minor = '2';
+
+-- This line concludes the schema upgrade to version 6.2.
+
+-- This line starts the schema upgrade to version 7.0.
+
+-- Add a lot (20+) of tables for the config backend.
+
+-- Adding on update trigger in MySQL is as easy as using this column definition in CREATE TABLE:
+-- modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+-- Sadly, Postgres has its own convoluted way of doing this. Luckily, the update pattern is
+-- the same in many tables, so we can define the trigger function once and the use it everywhere.
+
+-- First, we need to define a function that will do the actual job.
+-- This is used in many, many tables.
+CREATE OR REPLACE FUNCTION modification_ts_update()
+  RETURNS trigger AS $modification_ts_update$
+  BEGIN
+    new.modification_ts = CURRENT_TIMESTAMP;
+    RETURN NULL;
+  END;
+
+-- Second, we need to specify which language it was written in.
+$modification_ts_update$ LANGUAGE plpgsql;
+
+-- Create table modification and insert values for modification types.
+CREATE TABLE modification (
+  id smallint NOT NULL,
+  modification_type VARCHAR(32) NOT NULL,
+  PRIMARY KEY (id)
+);
+INSERT INTO modification VALUES (0,'create'), (1,'update'), (2,'delete');
+
+-- Now create the table that holds different parameter data types.
+CREATE TABLE parameter_data_type (
+  id smallint NOT NULL,
+  name VARCHAR(32) NOT NULL,
+  PRIMARY KEY (id)
+);
+INSERT INTO parameter_data_type VALUES
+    (0,'integer'),
+    (1,'real'),
+    (2,'boolean'),
+    (4,'string');
+
+-- This table doesn't exist in MySQL. However, it's nice to have an enum that explains what the values
+-- in ddns_replace_client_name field in the dhcp{4,6}_shared_network table means.
+CREATE TABLE ddns_replace_client_name_types (
+  type INT8 PRIMARY KEY NOT NULL,
+  name VARCHAR(32)
+);
+-- See enum ReplaceClientNameMode in src/lib/dhcpsrv/d2_client_cfg.h
+INSERT INTO ddns_replace_client_name_types (type, name) VALUES
+  (0, 'RCM_NEVER'),
+  (1, 'RCM_ALWAYS'),
+  (2, 'RCM_WHEN_PRESENT'),
+  (3, 'RCM_WHEN_NOT_PRESENT');
+
+-- Create table for DHCPv6 servers
+CREATE TABLE dhcp6_server (
+  id SERIAL PRIMARY KEY NOT NULL,
+  tag VARCHAR(64) NOT NULL,
+  description TEXT DEFAULT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  UNIQUE(tag)
+);
+CREATE INDEX dhcp6_server_idx1 ON dhcp6_server (modification_ts);
+CREATE UNIQUE INDEX dhcp6_server_idx2 ON dhcp6_server(tag);
+CREATE TRIGGER dhcp6_server_modification_ts_update
+  AFTER UPDATE ON dhcp6_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+INSERT INTO dhcp6_server (tag, description) VALUES ('all','special type: all servers');
+
+-- Create a table for storing IPv6 shared networks
+CREATE TABLE dhcp6_shared_network (
+  id SERIAL PRIMARY KEY NOT NULL,
+  name VARCHAR(128) UNIQUE NOT NULL,
+  client_class VARCHAR(128) DEFAULT NULL,
+  interface VARCHAR(128) DEFAULT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  preferred_lifetime BIGINT DEFAULT NULL,
+  rapid_commit BOOLEAN DEFAULT NULL,
+  rebind_timer BIGINT DEFAULT NULL,
+  relay TEXT DEFAULT NULL,
+  renew_timer BIGINT DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  valid_lifetime BIGINT DEFAULT NULL,
+  calculate_tee_times BOOLEAN DEFAULT NULL,
+  t1_percent float DEFAULT NULL,
+  t2_percent float DEFAULT NULL,
+  interface_id BYTEA DEFAULT NULL, -- 128 bytes
+  min_preferred_lifetime BIGINT DEFAULT NULL,
+  max_preferred_lifetime BIGINT DEFAULT NULL,
+  min_valid_lifetime BIGINT DEFAULT NULL,
+  max_valid_lifetime BIGINT DEFAULT NULL,
+  ddns_send_updates BOOLEAN DEFAULT NULL,
+  ddns_override_no_update BOOLEAN DEFAULT NULL,
+  ddns_override_client_update BOOLEAN DEFAULT NULL,
+  ddns_replace_client_name INT8 DEFAULT NULL,
+  ddns_generated_prefix VARCHAR(255) DEFAULT NULL,
+  ddns_qualifying_suffix VARCHAR(255) DEFAULT NULL,
+  reservations_global BOOLEAN DEFAULT NULL,
+  reservations_in_subnet BOOLEAN DEFAULT NULL,
+  reservations_out_of_pool BOOLEAN DEFAULT NULL,
+  cache_threshold float DEFAULT NULL,
+  cache_max_age BIGINT DEFAULT NULL,
+  CONSTRAINT fk_ddns_replace_client_name FOREIGN KEY (ddns_replace_client_name)
+    REFERENCES ddns_replace_client_name_types (type)
+);
+CREATE INDEX dhcp6_shared_network_idx1 ON dhcp6_shared_network (name);
+
+CREATE TRIGGER dhcp6_shared_network_modification_ts_update
+  AFTER UPDATE ON dhcp6_shared_network
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Now we need to create a relationship between defined shared networks and the servers
+CREATE TABLE dhcp6_shared_network_server (
+  shared_network_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (shared_network_id, server_id),
+  CONSTRAINT fk_dhcp6_shared_network_server_server_id FOREIGN KEY (server_id)
+    REFERENCES dhcp6_server (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp6_shared_network_server_shared_network_id FOREIGN KEY (shared_network_id)
+    REFERENCES dhcp6_shared_network (id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+CREATE INDEX dhcp6_shared_network_server_idx1 ON dhcp6_shared_network_server (modification_ts);
+CREATE INDEX dhcp6_shared_network_server_idx2 ON dhcp6_shared_network_server (server_id);
+
+-- Create a list of IPv6 subnets
+CREATE TABLE dhcp6_subnet (
+  subnet_id BIGINT PRIMARY KEY NOT NULL,
+  subnet_prefix VARCHAR(64) UNIQUE NOT NULL,
+  client_class VARCHAR(128) DEFAULT NULL,
+  interface VARCHAR(128) DEFAULT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  preferred_lifetime BIGINT DEFAULT NULL,
+  rapid_commit BOOLEAN DEFAULT NULL,
+  rebind_timer BIGINT DEFAULT NULL,
+  relay TEXT DEFAULT NULL,
+  renew_timer BIGINT DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  shared_network_name VARCHAR(128) DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  valid_lifetime BIGINT DEFAULT NULL,
+  calculate_tee_times BOOLEAN DEFAULT NULL,
+  t1_percent float DEFAULT NULL,
+  t2_percent float DEFAULT NULL,
+  interface_id BYTEA DEFAULT NULL,
+  min_preferred_lifetime BIGINT DEFAULT NULL,
+  max_preferred_lifetime BIGINT DEFAULT NULL,
+  min_valid_lifetime BIGINT DEFAULT NULL,
+  max_valid_lifetime BIGINT DEFAULT NULL,
+  ddns_send_updates BOOLEAN DEFAULT NULL,
+  ddns_override_no_update BOOLEAN DEFAULT NULL,
+  ddns_override_client_update BOOLEAN DEFAULT NULL,
+  ddns_replace_client_name INT8 DEFAULT NULL,
+  ddns_generated_prefix VARCHAR(255) DEFAULT NULL,
+  ddns_qualifying_suffix VARCHAR(255) DEFAULT NULL,
+  reservations_global BOOLEAN DEFAULT NULL,
+  reservations_in_subnet BOOLEAN DEFAULT NULL,
+  reservations_out_of_pool BOOLEAN DEFAULT NULL,
+  cache_threshold float DEFAULT NULL,
+  cache_max_age BIGINT DEFAULT NULL,
+  CONSTRAINT fk_dhcp6_subnet_shared_network FOREIGN KEY (shared_network_name)
+    REFERENCES dhcp6_shared_network (name) ON DELETE SET NULL ON UPDATE NO ACTION,
+  CONSTRAINT fk_ddns_replace_client_name FOREIGN KEY (ddns_replace_client_name)
+    REFERENCES ddns_replace_client_name_types (type)
+);
+
+CREATE TRIGGER dhcp6_subnet_modification_ts_update
+  AFTER UPDATE ON dhcp6_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+CREATE INDEX dhcp6_subnet_idx1 ON dhcp6_subnet (modification_ts);
+CREATE INDEX dhcp6_subnet_idx2 ON dhcp6_subnet (shared_network_name);
+
+-- Create a table that holds all address pools in IPv6.
+CREATE TABLE dhcp6_pool (
+  id SERIAL PRIMARY KEY NOT NULL,
+  start_address inet NOT NULL,
+  end_address inet NOT NULL,
+  subnet_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  client_class VARCHAR(128) DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  CONSTRAINT fk_dhcp6_pool_subnet_id FOREIGN KEY (subnet_id) REFERENCES dhcp6_subnet (subnet_id)
+);
+CREATE INDEX dhcp6_pool_idx1 ON dhcp6_pool (modification_ts);
+CREATE INDEX dhcp6_pool_idx2 ON dhcp6_pool (subnet_id);
+
+CREATE TRIGGER dhcp6_pool_modification_ts_update
+  AFTER UPDATE ON dhcp6_pool
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- And now the same, but for PD pools.
+CREATE TABLE dhcp6_pd_pool (
+  id SERIAL PRIMARY KEY NOT NULL,
+  prefix VARCHAR(45) NOT NULL,
+  prefix_length SMALLINT NOT NULL,
+  delegated_prefix_length SMALLINT NOT NULL,
+  subnet_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  excluded_prefix VARCHAR(45) DEFAULT NULL,
+  excluded_prefix_length SMALLINT NOT NULL,
+  client_class VARCHAR(128) DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  CONSTRAINT fk_dhcp6_pd_pool_subnet_id FOREIGN KEY (subnet_id) REFERENCES dhcp6_subnet(subnet_id)
+);
+
+CREATE INDEX dhcp6_pd_pool_idx1 ON dhcp6_pd_pool (modification_ts);
+CREATE INDEX dhcp6_pd_pool_idx2 ON dhcp6_pd_pool (subnet_id);
+CREATE TRIGGER dhcp6_pd_pool_modification_ts_update
+  AFTER UPDATE ON dhcp6_pd_pool
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+CREATE TABLE dhcp6_subnet_server (
+  subnet_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (subnet_id, server_id),
+  CONSTRAINT fk_dhcp6_subnet_server_server_id
+    FOREIGN KEY (server_id) REFERENCES dhcp6_server (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp6_subnet_server_subnet_id
+    FOREIGN KEY (subnet_id) REFERENCES dhcp6_subnet (subnet_id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  UNIQUE (subnet_id, server_id)
+);
+CREATE INDEX dhcp6_subnet_server_idx1 ON dhcp6_subnet_server(server_id);
+CREATE INDEX dhcp6_subnet_server_idx2 ON dhcp6_subnet_server(modification_ts);
+CREATE TRIGGER dhcp6_subnet_server_modification_ts_update
+  AFTER UPDATE ON dhcp6_subnet_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Create table for storing global DHCPv6 parameters.
+CREATE TABLE dhcp6_global_parameter (
+  id SERIAL PRIMARY KEY NOT NULL,
+  name VARCHAR(128) NOT NULL,
+  value TEXT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  parameter_type SMALLINT NOT NULL,
+  CONSTRAINT fk_dhcp6_global_parameter_type FOREIGN KEY (parameter_type) REFERENCES parameter_data_type(id)
+);
+
+CREATE INDEX key_dhcp6_global_parameter_idx1 ON dhcp6_global_parameter(modification_ts);
+CREATE INDEX key_dhcp6_global_parameter_idx2 ON dhcp6_global_parameter(name);
+
+CREATE TRIGGER dhcp6_global_parameter_modification_ts_update
+  AFTER UPDATE ON dhcp6_global_parameter
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+CREATE TABLE dhcp6_global_parameter_server (
+  parameter_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (parameter_id, server_id),
+  CONSTRAINT fk_dhcp6_global_parameter_server_parameter_id FOREIGN KEY (parameter_id)
+    REFERENCES dhcp6_global_parameter(id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp6_global_parameter_server_server_id FOREIGN KEY (server_id)
+    REFERENCES dhcp6_server(id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+
+CREATE INDEX key_dhcp6_global_parameter_server_idx1 ON dhcp6_global_parameter_server(modification_ts);
+CREATE TRIGGER dhcp6_global_parameter_server_modification_ts_update
+  AFTER UPDATE ON dhcp6_global_parameter_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Alter table for storing DHCPv6 options.
+ALTER TABLE dhcp6_options
+  ADD COLUMN shared_network_name VARCHAR(128) DEFAULT NULL,
+  ADD COLUMN pool_id BIGINT DEFAULT NULL,
+  ADD COLUMN pd_pool_id BIGINT DEFAULT NULL,
+  ADD COLUMN modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  ADD CONSTRAINT fk_dhcp6_options_pd_pool FOREIGN KEY (pd_pool_id)
+    REFERENCES dhcp6_pd_pool(id) ON DELETE CASCADE ON UPDATE CASCADE,
+  ADD CONSTRAINT fk_dhcp6_options_pool FOREIGN KEY (pool_id)
+    REFERENCES dhcp6_pool (id) ON DELETE CASCADE ON UPDATE CASCADE,
+  ADD CONSTRAINT fk_dhcp6_options_shared_network FOREIGN KEY (shared_network_name)
+    REFERENCES dhcp6_shared_network (name) ON DELETE CASCADE ON UPDATE CASCADE;
+
+CREATE TRIGGER dhcp6_options_modification_ts_update
+  AFTER UPDATE ON dhcp6_options
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Now create a table for associating defined options with servers.
+CREATE TABLE dhcp6_options_server (
+  option_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (option_id, server_id),
+  CONSTRAINT fk_dhcp6_options_server_option_id FOREIGN KEY (option_id)
+    REFERENCES dhcp6_options (option_id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp6_options_server_server_id FOREIGN KEY (server_id)
+    REFERENCES dhcp6_server (id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+CREATE INDEX dhcp6_options_server_idx1 ON dhcp6_options_server(server_id);
+CREATE INDEX dhcp6_options_server_idx2 ON dhcp6_options_server(modification_ts);
+CREATE TRIGGER dhcp6_options_server_modification_ts_update
+  AFTER UPDATE ON dhcp6_options_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- This table is for storing IPv6 option definitions
+CREATE TABLE dhcp6_option_def (
+  id SERIAL PRIMARY KEY UNIQUE NOT NULL,
+  code SMALLINT NOT NULL,
+  name VARCHAR(128) NOT NULL,
+  space VARCHAR(128) NOT NULL,
+  type SMALLINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  is_array BOOLEAN NOT NULL,
+  encapsulate VARCHAR(128) NOT NULL,
+  record_types VARCHAR DEFAULT NULL,
+  user_context JSON DEFAULT NULL
+);
+CREATE INDEX dhcp6_option_def_idx1 ON dhcp6_option_def(modification_ts);
+CREATE INDEX dhcp6_option_def_idx2 ON dhcp6_option_def(code, space);
+CREATE TRIGGER dhcp6_option_def_modification_ts_update
+  AFTER UPDATE ON dhcp6_option_def
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- and another table for storing relationship between option definitions and servers.
+CREATE TABLE dhcp6_option_def_server (
+  option_def_id BIGINT NOT NULL REFERENCES dhcp6_option_def (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  server_id BIGINT NOT NULL REFERENCES dhcp6_server (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (option_def_id, server_id)
+);
+CREATE TRIGGER dhcp6_option_def_server_modification_ts_update
+  AFTER UPDATE ON dhcp6_option_def_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Now create two tables for audit revisions...
+CREATE TABLE dhcp6_audit_revision (
+  id SERIAL PRIMARY KEY NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  log_message TEXT DEFAULT NULL,
+  server_id BIGINT DEFAULT NULL
+);
+CREATE TRIGGER dhcp6_audit_revision_modification_ts_update
+  AFTER UPDATE ON dhcp6_audit_revision
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- ... and the DHCPv6 audit itself.
+CREATE TABLE dhcp6_audit (
+  id SERIAL UNIQUE NOT NULL,
+  object_type VARCHAR(256) NOT NULL,
+  object_id BIGINT NOT NULL,
+  modification_type SMALLINT NOT NULL,
+  revision_id BIGINT NOT NULL,
+  CONSTRAINT fk_dhcp6_audit_modification_type FOREIGN KEY (modification_type)
+    REFERENCES modification (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp6_audit_revision FOREIGN KEY (revision_id)
+    REFERENCES dhcp6_audit_revision (id) ON DELETE NO ACTION ON UPDATE CASCADE
+);
+CREATE TRIGGER dhcp6_audit_modification_ts_update
+  AFTER UPDATE ON dhcp6_audit
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+CREATE INDEX dhcp6_audit_idx1 ON dhcp6_audit (modification_type);
+CREATE INDEX dhcp6_audit_idx2 ON dhcp6_audit (revision_id);
+
+-- Create table for DHCPv4 servers
+CREATE TABLE dhcp4_server (
+  id SERIAL PRIMARY KEY NOT NULL,
+  tag VARCHAR(64) NOT NULL,
+  description TEXT DEFAULT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  UNIQUE(tag)
+);
+CREATE INDEX dhcp4_server_modification_ts ON dhcp6_server (modification_ts);
+CREATE TRIGGER dhcp4_server_modification_ts_update
+  AFTER UPDATE ON dhcp4_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+INSERT INTO dhcp4_server (tag, description) VALUES ('all','special type: all servers');
+
+-- Create table for storing global DHCPv4 parameters.
+CREATE TABLE dhcp4_global_parameter (
+  id SERIAL PRIMARY KEY NOT NULL,
+  name VARCHAR(128) NOT NULL,
+  value TEXT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  parameter_type SMALLINT NOT NULL,
+  CONSTRAINT fk_dhcp6_global_parameter_type FOREIGN KEY (parameter_type) REFERENCES parameter_data_type(id)
+);
+CREATE INDEX dhcp4_global_parameter_idx1 ON dhcp4_global_parameter(modification_ts);
+CREATE INDEX dhcp4_global_parameter_idx2 ON dhcp4_global_parameter(name);
+
+CREATE TRIGGER dhcp4_global_parameter_modification_ts_update
+  AFTER UPDATE ON dhcp4_global_parameter
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- and create mapping for the global DHCPv4 parameters mapping to servers
+CREATE TABLE dhcp4_global_parameter_server (
+  parameter_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (parameter_id, server_id),
+  CONSTRAINT fk_dhcp4_global_parameter_server_parameter_id FOREIGN KEY (parameter_id)
+    REFERENCES dhcp4_global_parameter(id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp4_global_parameter_server_server_id FOREIGN KEY (server_id)
+    REFERENCES dhcp4_server(id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+CREATE INDEX key_dhcp4_global_parameter_idx1 ON dhcp4_global_parameter_server(modification_ts);
+CREATE TRIGGER dhcp4_global_parameter_server_modification_ts_update
+  AFTER UPDATE ON dhcp4_global_parameter_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Create a table for storing IPv4 shared networks
+CREATE TABLE dhcp4_shared_network (
+  id SERIAL PRIMARY KEY NOT NULL,
+  name VARCHAR(128) UNIQUE NOT NULL,
+  client_class VARCHAR(128) DEFAULT NULL,
+  interface VARCHAR(128) DEFAULT NULL,
+  match_client_id BOOLEAN DEFAULT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  rebind_timer BIGINT DEFAULT NULL,
+  relay TEXT DEFAULT NULL,
+  renew_timer BIGINT DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  valid_lifetime BIGINT DEFAULT NULL,
+  authoritative BOOLEAN DEFAULT NULL,
+  calculate_tee_times BOOLEAN DEFAULT NULL,
+  t1_percent float DEFAULT NULL,
+  t2_percent float DEFAULT NULL,
+  boot_file_name VARCHAR(128) DEFAULT NULL,
+  next_server inet DEFAULT NULL,   -- let's use type inet
+  server_hostname VARCHAR(64) DEFAULT NULL,
+  min_valid_lifetime BIGINT DEFAULT NULL,
+  max_valid_lifetime BIGINT DEFAULT NULL,
+  ddns_send_updates BOOLEAN DEFAULT NULL,
+  ddns_override_no_update BOOLEAN DEFAULT NULL,
+  ddns_override_client_update BOOLEAN DEFAULT NULL,
+  ddns_replace_client_name INT8 DEFAULT NULL,
+  ddns_generated_prefix VARCHAR(255) DEFAULT NULL,
+  ddns_qualifying_suffix VARCHAR(255) DEFAULT NULL,
+  reservations_global BOOLEAN DEFAULT NULL,
+  reservations_in_subnet BOOLEAN DEFAULT NULL,
+  reservations_out_of_pool BOOLEAN DEFAULT NULL,
+  cache_threshold float DEFAULT NULL,
+  cache_max_age BIGINT DEFAULT NULL,
+  CONSTRAINT fk_ddns_replace_client_name FOREIGN KEY (ddns_replace_client_name)
+    REFERENCES ddns_replace_client_name_types (type)
+);
+
+CREATE UNIQUE INDEX dhcp4_shared_network_idx1 ON dhcp4_shared_network (name);
+CREATE INDEX dhcp4_shared_network_idx2 ON dhcp4_shared_network (modification_ts);
+
+CREATE TRIGGER dhcp4_shared_network_modification_ts_update
+  AFTER UPDATE ON dhcp4_shared_network
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Now we need to create a relationship between defined shared networks and the servers
+CREATE TABLE dhcp4_shared_network_server (
+  shared_network_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (shared_network_id, server_id),
+  CONSTRAINT fk_dhcp4_shared_network_server_server_id FOREIGN KEY (server_id)
+    REFERENCES dhcp4_server (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp4_shared_network_server_shared_network_id FOREIGN KEY (shared_network_id)
+    REFERENCES dhcp4_shared_network (id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+CREATE INDEX dhcp4_shared_network_server_idx1 ON dhcp4_shared_network_server (modification_ts);
+CREATE INDEX dhcp4_shared_network_server_idx2 ON dhcp4_shared_network_server (server_id);
+
+-- Create a list of IPv4 subnets
+CREATE TABLE dhcp4_subnet (
+  subnet_id BIGINT PRIMARY KEY NOT NULL,
+  subnet_prefix VARCHAR(64) UNIQUE NOT NULL,
+  interface_4o6 VARCHAR(128) DEFAULT NULL,
+  interface_id_4o6 VARCHAR(128) DEFAULT NULL,
+  subnet_4o6 VARCHAR(64) DEFAULT NULL,
+  boot_file_name VARCHAR(128) DEFAULT NULL,
+  client_class VARCHAR(128) DEFAULT NULL,
+  interface VARCHAR(128) DEFAULT NULL,
+  match_client_id BOOLEAN DEFAULT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  next_server inet DEFAULT NULL,
+  rebind_timer BIGINT DEFAULT NULL,
+  relay TEXT DEFAULT NULL,
+  renew_timer BIGINT DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  server_hostname VARCHAR(64) DEFAULT NULL,
+  shared_network_name VARCHAR(128) DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  valid_lifetime BIGINT DEFAULT NULL,
+  authoritative BOOLEAN DEFAULT NULL,
+  calculate_tee_times BOOLEAN DEFAULT NULL,
+  t1_percent float DEFAULT NULL,
+  t2_percent float DEFAULT NULL,
+  min_valid_lifetime BIGINT DEFAULT NULL,
+  max_valid_lifetime BIGINT DEFAULT NULL,
+  ddns_send_updates BOOLEAN DEFAULT NULL,
+  ddns_override_no_update BOOLEAN DEFAULT NULL,
+  ddns_override_client_update BOOLEAN DEFAULT NULL,
+  ddns_replace_client_name INT8 DEFAULT NULL,
+  ddns_generated_prefix VARCHAR(255) DEFAULT NULL,
+  ddns_qualifying_suffix VARCHAR(255) DEFAULT NULL,
+  reservations_global BOOLEAN DEFAULT NULL,
+  reservations_in_subnet BOOLEAN DEFAULT NULL,
+  reservations_out_of_pool BOOLEAN DEFAULT NULL,
+  cache_threshold float DEFAULT NULL,
+  cache_max_age BIGINT DEFAULT NULL,
+  CONSTRAINT fk_dhcp4_subnet_shared_network FOREIGN KEY (shared_network_name)
+    REFERENCES dhcp4_shared_network (name) ON DELETE SET NULL ON UPDATE NO ACTION,
+  CONSTRAINT fk_ddns_replace_client_name FOREIGN KEY (ddns_replace_client_name)
+    REFERENCES ddns_replace_client_name_types (type)
+);
+
+CREATE TRIGGER dhcp4_subnet_modification_ts_update
+  AFTER UPDATE ON dhcp4_subnet
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+CREATE INDEX dhcp4_subnet_idx1 ON dhcp4_subnet (modification_ts);
+CREATE INDEX dhcp4_subnet_idx2 ON dhcp4_subnet (shared_network_name);
+
+CREATE TABLE dhcp4_subnet_server (
+  subnet_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (subnet_id, server_id),
+  CONSTRAINT fk_dhcp6_subnet_server_server_id
+    FOREIGN KEY (server_id) REFERENCES dhcp6_server (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp6_subnet_server_subnet_id
+    FOREIGN KEY (subnet_id) REFERENCES dhcp6_subnet (subnet_id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  UNIQUE (subnet_id, server_id)
+);
+CREATE INDEX dhcp4_subnet_server_idx1 ON dhcp4_subnet_server(server_id);
+CREATE INDEX dhcp4_subnet_server_idx2 ON dhcp4_subnet_server(modification_ts);
+CREATE TRIGGER dhcp4_subnet_server_modification_ts_update
+  AFTER UPDATE ON dhcp4_subnet_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Create a table that holds all address pools in IPv4.
+CREATE TABLE dhcp4_pool (
+  id SERIAL PRIMARY KEY NOT NULL,
+  start_address inet NOT NULL,
+  end_address inet NOT NULL,
+  subnet_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  client_class VARCHAR(128) DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  CONSTRAINT fk_dhcp4_pool_subnet_id FOREIGN KEY (subnet_id) REFERENCES dhcp4_subnet (subnet_id)
+);
+CREATE INDEX dhcp4_pool_idx1 ON dhcp4_pool (modification_ts);
+CREATE INDEX dhcp4_pool_idx2 ON dhcp4_pool (subnet_id);
+
+CREATE TRIGGER dhcp4_pool_modification_ts_update
+  AFTER UPDATE ON dhcp4_pool
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- ALTER table for storing DHCPv4 options.
+ALTER TABLE dhcp4_options
+  ADD COLUMN shared_network_name VARCHAR(128) DEFAULT NULL,
+  ADD COLUMN pool_id BIGINT DEFAULT NULL,
+  ADD COLUMN modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  ADD CONSTRAINT fk_dhcp4_options_pool FOREIGN KEY (pool_id)
+    REFERENCES dhcp4_pool (id) ON DELETE CASCADE ON UPDATE CASCADE,
+  ADD CONSTRAINT fk_dhcp4_options_shared_network FOREIGN KEY (shared_network_name)
+    REFERENCES dhcp4_shared_network (name) ON DELETE CASCADE ON UPDATE CASCADE;
+
+CREATE TRIGGER dhcp4_options_modification_ts_update
+  AFTER UPDATE ON dhcp4_options
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Now create a table for associating defined v4 options with servers.
+CREATE TABLE dhcp4_options_server (
+  option_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (option_id, server_id),
+  CONSTRAINT fk_dhcp4_options_server_option_id FOREIGN KEY (option_id)
+    REFERENCES dhcp4_options (option_id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp4_options_server_server_id FOREIGN KEY (server_id)
+    REFERENCES dhcp4_server (id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+CREATE INDEX dhcp4_options_server_idx1 ON dhcp4_options_server(server_id);
+CREATE INDEX dhcp4_options_server_idx2 ON dhcp4_options_server(modification_ts);
+CREATE TRIGGER dhcp4_options_server_modification_ts_update
+  AFTER UPDATE ON dhcp4_options_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- This table is for storing IPv4 option definitions
+CREATE TABLE dhcp4_option_def (
+  id SERIAL PRIMARY KEY UNIQUE NOT NULL,
+  code SMALLINT NOT NULL,
+  name VARCHAR(128) NOT NULL,
+  space VARCHAR(128) NOT NULL,
+  type SMALLINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  is_array BOOLEAN NOT NULL,
+  encapsulate VARCHAR(128) NOT NULL,
+  record_types VARCHAR DEFAULT NULL,
+  user_context JSON DEFAULT NULL
+);
+CREATE INDEX dhcp4_option_def_idx1 ON dhcp4_option_def(modification_ts);
+CREATE INDEX dhcp4_option_def_idx2 ON dhcp4_option_def(code, space);
+CREATE TRIGGER dhcp4_option_def_modification_ts_update
+  AFTER UPDATE ON dhcp4_option_def
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- and another table for storing relationship between option definitions and servers.
+CREATE TABLE dhcp4_option_def_server (
+  option_def_id BIGINT NOT NULL REFERENCES dhcp6_option_def (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  server_id BIGINT NOT NULL REFERENCES dhcp4_server (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (option_def_id, server_id)
+);
+CREATE TRIGGER dhcp4_option_def_server_modification_ts_update
+  AFTER UPDATE ON dhcp4_option_def_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Now create two tables for audit revisions...
+CREATE TABLE dhcp4_audit_revision (
+  id SERIAL PRIMARY KEY NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  log_message TEXT DEFAULT NULL,
+  server_id BIGINT DEFAULT NULL
+);
+CREATE TRIGGER dhcp4_audit_revision_modification_ts_update
+  AFTER UPDATE ON dhcp4_audit_revision
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- ... and the DHCPv4 audit itself.
+CREATE TABLE dhcp4_audit (
+  id SERIAL UNIQUE NOT NULL,
+  object_type VARCHAR(256) NOT NULL,
+  object_id BIGINT NOT NULL,
+  modification_type SMALLINT NOT NULL,
+  revision_id BIGINT NOT NULL,
+  CONSTRAINT fk_dhcp4_audit_modification_type FOREIGN KEY (modification_type)
+    REFERENCES modification (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp4_audit_revision FOREIGN KEY (revision_id)
+    REFERENCES dhcp4_audit_revision (id) ON DELETE NO ACTION ON UPDATE CASCADE
+);
+CREATE TRIGGER dhcp4_audit_modification_ts_update
+  AFTER UPDATE ON dhcp4_audit
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+CREATE INDEX dhcp4_audit_idx1 ON dhcp4_audit (modification_type);
+CREATE INDEX dhcp4_audit_idx2 ON dhcp4_audit (revision_id);
+
+-- Stores a TEXT value to a session variable
+-- name name of session variable to set
+-- value TEXT value to store
+CREATE OR REPLACE FUNCTION set_session_value(name text, value TEXT)
+RETURNS VOID
+AS $$
+DECLARE
+BEGIN
+    PERFORM set_config(name, value, false);
+    RETURN;
+
+    EXCEPTION
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'set_session_value(%) : value:[%] failed, sqlstate: %', name, value, sqlstate;
+END;$$
+LANGUAGE plpgsql;
+
+-- Stores a BIGINT value to a session variable
+-- Note the value converted to TEXT and then stored as Postgresql does
+-- not support any other data type in session variables.
+-- name name of session variable to set
+-- value BIGINT value to store
+CREATE OR REPLACE FUNCTION set_session_value(name text, value BIGINT)
+RETURNS VOID
+AS $$
+BEGIN
+    PERFORM set_config(name, cast(value as text), false);
+    RETURN;
+
+    EXCEPTION
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'set_session_value(%) : value:[%] failed, sqlstate: %', name, value, sqlstate;
+END;$$
+LANGUAGE plpgsql;
+
+-- Stores a BOOLEAN value to a session variable
+-- Note the value converted to TEXT and then stored as Postgresql does
+-- not support any other data type in session variables.
+-- name name of session variable to set
+-- value BOOLEAN value to store
+CREATE OR REPLACE FUNCTION set_session_value(name text, value BOOLEAN)
+RETURNS VOID
+AS $$
+BEGIN
+    PERFORM set_config(name, cast(value as text), false);
+    RETURN;
+
+    EXCEPTION
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'set_session_value(%) : value:[%] failed, sqlstate: %', name, value, sqlstate;
+END;$$
+LANGUAGE plpgsql;
+
+-- Fetches a text value from the session configuration.
+-- param name name of the session variable to fetch
+-- If the name is not found it returns NULL.
+-- Postgresql allows you to store custom session values
+-- but throws an exception if they have not first been
+-- set.  This allows us to be a bit more graceful.
+CREATE OR REPLACE FUNCTION get_session_value(name TEXT)
+RETURNS TEXT
+AS $$
+DECLARE
+    text_value TEXT := '';
+BEGIN
+    text_value = current_setting(name);
+    RETURN(text_value);
+
+    EXCEPTION
+    WHEN undefined_object THEN
+        -- Variable has not been initialized so return NULL
+        RETURN NULL;
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'get_session_value(%, TEXT) failed, sqlstate: %', name, sqlstate;
+END;$$
+LANGUAGE plpgsql;
+
+-- Fetches an BIGINT value from the session configuration.
+-- param name name of the session variable to fetch
+-- If the name is not found it returns zero.
+CREATE OR REPLACE FUNCTION get_session_big_int(name text)
+RETURNS BIGINT
+AS $$
+DECLARE
+    int_value BIGINT := 0;
+    text_value TEXT := '';
+BEGIN
+    text_value = get_session_value(name);
+    IF text_value is NULL or text_value = '' THEN
+        RETURN(0);
+    END IF;
+
+    int_value = cast(text_value as BIGINT);
+    RETURN(int_value);
+
+    EXCEPTION
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'get_session_big_int(%) failed - text:[%] , sqlstate: %', name, text_value, sqlstate;
+
+END;$$
+LANGUAGE plpgsql;
+
+-- Fetches an BOOLEAN value from the session configuration.
+-- param name name of the session variable to fetch
+-- If the name is not found it returns zero.
+CREATE OR REPLACE FUNCTION get_session_boolean(name text)
+RETURNS BOOLEAN
+AS $$
+DECLARE
+    bool_value BOOLEAN := false;
+    text_value TEXT := '';
+BEGIN
+    text_value = get_session_value(name);
+    IF text_value is NULL or text_value = '' THEN
+        RETURN(false);
+    END IF;
+
+    bool_value = cast(text_value as BOOLEAN);
+    RETURN(bool_value);
+
+    EXCEPTION
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'get_session_boolean(%) failed - text:[%] , sqlstate: %', name, text_value, sqlstate;
+
+END;$$
+LANGUAGE plpgsql;
+
+-- -----------------------------------------------------
+-- Stored procedure which creates a new entry in the
+-- dhcp4_audit_revision table and sets appropriate session
+-- variables to be used while creating the audit entries
+-- by triggers. This procedure should be called at the
+-- beginning of a transaction which modifies configuration
+-- data in the database, e.g. when new subnet is added.
+--
+-- Parameters:
+-- - audit_ts timestamp to be associated with the audit
+--   revision.
+-- - server_tag is used to retrieve the server_id which
+--   associates the changes applied with the particular
+--   server or all servers.
+-- - audit_log_message is a log message associates with
+--   the audit revision.
+-- - cascade_transaction is assigned to a session
+--   variable which is used in some triggers to determine
+--   if the audit entry should be created for them or
+--   not. Specifically, this is used when DHCP options
+--   are inserted, updated or deleted. If such modification
+--   is a part of the larger change (e.g. change in the
+--   subnet the options belong to) the dedicated audit
+--   entry for options must not be created. On the other
+--   hand, if the global option is being added, the
+--   audit entry for the option must be created because
+--   it is the sole object modified in that case.
+--   Session variable disable_audit is used to disable
+--   the procedure when wiping the database during
+--   unit tests.  This avoids issues with revision_id
+--   being null.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createAuditRevisionDHCP4(audit_ts TIMESTAMP WITH TIME ZONE,
+                                                    server_tag VARCHAR(64),
+                                                    audit_log_message TEXT,
+                                                    cascade_transaction BOOLEAN)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    disable_audit BOOLEAN := false;
+    audit_revision_id BIGINT;
+    srv_id BIGINT;
+BEGIN
+    -- Fetch session value for disable_audit.
+    disable_audit := get_session_boolean('kea.disable_audit');
+    IF disable_audit = false THEN
+        SELECT id INTO srv_id FROM dhcp4_server WHERE tag = server_tag;
+        INSERT INTO dhcp4_audit_revision (modification_ts, server_id, log_message)
+            VALUES (audit_ts, srv_id, audit_log_message) returning id INTO audit_revision_id;
+
+        -- Update pertinent session variables.
+        PERFORM set_session_value('kea.audit_revision_id', audit_revision_id);
+        PERFORM set_session_value('kea.cascade_transaction', cascade_transaction);
+    END IF;
+    RETURN;
+END;$$;
+
+-- -----------------------------------------------------
+-- Stored procedure which creates a new entry in the
+-- dhcp4_audit table. It should be called from the
+-- triggers of the tables where the config modifications
+-- are applied. The audit_revision_id variable contains
+-- the revision id to be placed in the audit entries.
+--
+-- The following parameters are passed to this procedure:
+-- - object_type_val: name of the table to be associated
+--   with the applied changes.
+-- - object_id_val: identifier of the modified object in
+--   that table.
+-- - modification_type_val: string value indicating the
+--   type of the change, i.e. 'create', 'update' or
+--   'delete'.
+--   Session variable disable_audit is used to disable
+--   the procedure when wiping the database during
+--   unit tests.  This avoids issues with revision_id
+--   being null.
+-- ----------------------------------------------------
+CREATE OR REPLACE FUNCTION createAuditEntryDHCP4(object_type_val VARCHAR(256),
+                                                 object_id_val BIGINT,
+                                                 modification_type_val VARCHAR(32))
+RETURNS VOID
+LANGUAGE plpgsql
+as $$
+DECLARE
+    audit_revision_id BIGINT;
+    disable_audit BOOLEAN := false;
+BEGIN
+    -- Fetch session value for disable_audit.
+    disable_audit := get_session_boolean('kea.disable_audit');
+
+    IF disable_audit IS NULL OR disable_audit = false THEN
+        -- Fetch session value most recently created audit_revision_id.
+        audit_revision_id := get_session_big_int('kea.audit_revision_id');
+        INSERT INTO dhcp4_audit (object_type, object_id, modification_type, revision_id)
+            VALUES (object_type_val, object_id_val,
+                (SELECT id FROM modification WHERE modification_type = modification_type_val),
+                 audit_revision_id);
+    END IF;
+    RETURN;
+END;$$;
+
+-- -----------------------------------------------------------------------
+-- Create a table holding the DHCPv4 client classes. Most table
+-- columns map directly to respective client class properties in
+-- Kea configuration. The depend_on_known_directly column is
+-- explicitly set in an insert or update statement to indicate
+-- if the client class directly depends on KNOWN or UNKNOWN
+-- built-in classes. A caller should determine it by evaluating
+-- a test expression before inserting or updating the client
+-- class in the database. The nullable follow_class_name column
+-- can be used for positioning the inserted or updated client
+-- class within the class hierarchy. Set this column value to
+-- an existing class name, after which this class should be
+-- placed in the class hierarchy. See dhcp4_client_class_order
+-- description for the details of how classes are ordered.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp4_client_class (
+    id SERIAL PRIMARY KEY NOT NULL,
+    name VARCHAR(128) UNIQUE NOT NULL,
+    test TEXT,
+    next_server INET DEFAULT NULL,
+    server_hostname VARCHAR(128) DEFAULT NULL,
+    boot_file_name VARCHAR(512) DEFAULT NULL,
+    only_if_required BOOLEAN NOT NULL DEFAULT false,
+    valid_lifetime BIGINT DEFAULT NULL,
+    min_valid_lifetime BIGINT DEFAULT NULL,
+    max_valid_lifetime BIGINT DEFAULT NULL,
+    depend_on_known_directly BOOLEAN NOT NULL DEFAULT false,
+    follow_class_name VARCHAR(128) DEFAULT NULL,
+    modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE INDEX key_dhcp4_client_class_modification_ts on dhcp4_client_class (modification_ts);
+
+-- -----------------------------------------------------------------------
+-- Create a table for ordering client classes and holding information
+-- about indirect dependencies on KNOWN/UKNOWN built-in client classes.
+-- Each class in the dhcp4_client_class table has a corresponding row
+-- in the dhcp4_client_class_order table. A caller should not modify
+-- the contents of this table. Its entries are automatically created
+-- upon inserting or updating client classes in the dhcp4_client_classes
+-- using triggers. The order_index designates the position of the client
+-- class within the class hierarchy. If the follow_class_name value of
+-- the dhcp4_client_class table is set to NULL, the client class is
+-- appended at the end of the hierarchy. The assigned order_index
+-- value for that class is set to a maximum current value + 1.
+-- If the follow_client_class specifies a name of an existing class,
+-- the generated order_index is set to an id of that class + 1, and
+-- the order_index values of the later classes are incremented by 1.
+-- The depend_on_known_indirectly column holds a boolean value indicating
+-- whether the given class depends on KNOWN/UKNOWN built-in classes
+-- via other classes, i.e. it depends on classes that directly or
+-- indirectly depend on these built-ins. This value is auto-generated
+-- by a trigger on the dhcp4_client_class_dependency table.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp4_client_class_order (
+    class_id BIGINT PRIMARY KEY NOT NULL,
+    order_index BIGINT NOT NULL,
+    depend_on_known_indirectly BOOLEAN NOT NULL DEFAULT false,
+    CONSTRAINT fk_dhcp4_client_class_order_class_id FOREIGN KEY (class_id)
+        REFERENCES dhcp4_client_class (id) ON DELETE CASCADE
+);
+
+CREATE INDEX key_dhcp4_client_class_order_index on dhcp4_client_class_order (order_index);
+
+-- -----------------------------------------------------------------------
+-- Stored procedure positioning an inserted or updated client class
+-- within the class hierarchy, depending on the value of the
+-- follow_class_name parameter.
+--
+-- Parameters:
+-- - id id of the positioned class,
+-- - follow_class_name name of the class after which this class should be
+--   positioned within the class hierarchy.
+-- - old_follow_class_name previous name of the class after which this
+--   class was positioned within the class hierarchy.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION setClientClass4Order(id BIGINT,
+                                                new_follow_class_name VARCHAR(128),
+                                                old_follow_class_name VARCHAR(128))
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    -- Used to fetch class's current value for depend_on_known_indirectly
+    l_depend_on_known_indirectly BIGINT := 0;
+
+    -- Optionally set if the follow_class_name column value is specified.
+    follow_class_index BIGINT;
+BEGIN
+    -- Fetch the class's current value of depend_on_known_indirectly.
+    SELECT depend_on_known_indirectly INTO l_depend_on_known_indirectly
+        FROM dhcp4_client_class_order WHERE id = class_id;
+
+    -- Save it to the current session for use elsewhere during this transaction.
+    -- Note this does not work prior to Postgres 9.2 unless the variables are
+    -- defined in postgresql.conf. I think for now we put up with CB not supported
+    -- prior to 9.2 or we tell people how to edit the conf file.
+    PERFORM set_session_value('kea.depend_on_known_indirectly', l_depend_on_known_indirectly);
+
+    -- Bail if the class is updated without re-positioning.
+    IF(
+       l_depend_on_known_indirectly IS NOT NULL AND
+       ((new_follow_class_name IS NULL AND old_follow_class_name IS NULL) OR
+        (new_follow_class_name = old_follow_class_name))
+    ) THEN
+        -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+        -- whenever the dhcp4_client_class record is updated. Such update may include
+        -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+        -- This value will be later adjusted when dependencies are inserted.
+        -- TKM should we update the session value also or is it moot?
+        UPDATE dhcp4_client_class_order SET depend_on_known_indirectly = false
+            WHERE class_id = id;
+        RETURN;
+    END IF;
+
+    IF new_follow_class_name IS NOT NULL THEN
+        -- Get the position of the class after which the new class should be added.
+        SELECT o.order_index INTO follow_class_index
+            FROM dhcp4_client_class AS c
+            INNER JOIN dhcp4_client_class_order AS o
+                ON c.id = o.class_id
+            WHERE c.name = new_follow_class_name;
+
+        IF follow_class_index IS NULL THEN
+            -- The class with a name specified with new_follow_class_name does
+            -- not exist.
+            RAISE EXCEPTION 'Class %s does not exist.', new_follow_class_name
+                USING ERRCODE = 'sql_routine_exception';
+        END IF;
+
+        -- We need to place the new class at the position of follow_class_index + 1.
+        -- There may be a class at this position already.
+        IF EXISTS(SELECT * FROM dhcp4_client_class_order WHERE order_index = follow_class_index + 1) THEN
+            -- There is a class at this position already. Let's move all classes
+            -- starting from this position by one to create a spot for the new
+            -- class.
+            UPDATE dhcp4_client_class_order
+                SET order_index = order_index + 1
+            WHERE order_index >= follow_class_index + 1;
+            -- TKM postgresql doesn't like order by here, does it matter?
+            -- ORDER BY order_index DESC;
+        END IF;
+
+    ELSE
+        -- A caller did not specify the new_follow_class_name value. Let's append the
+        -- new class at the end of the hierarchy.
+        SELECT MAX(order_index) INTO follow_class_index FROM dhcp4_client_class_order;
+        IF follow_class_index IS NULL THEN
+            -- Apparently, there are no classes. Let's start from 0.
+            follow_class_index = 0;
+        END IF;
+    END IF;
+
+    -- Check if moving the class doesn't break dependent classes.
+    IF EXISTS(
+        SELECT 1 FROM dhcp4_client_class_dependency AS d
+            INNER JOIN dhcp4_client_class_order AS o
+                ON d.class_id = o.class_id
+            WHERE d.dependency_id = id AND o.order_index < follow_class_index + 1
+        LIMIT 1
+    ) THEN
+        RAISE EXCEPTION 'Unable to move class with id %s because it would break its dependencies', id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+    -- whenever the dhcp4_client_class record is updated. Such update may include
+    -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+    -- This value will be later adjusted when dependencies are inserted.
+    -- ON CONFLICT required 9.5 or later
+    UPDATE dhcp4_client_class_order
+        SET order_index = follow_class_index + 1,
+            depend_on_known_indirectly = l_depend_on_known_indirectly
+        WHERE class_id = id;
+    IF FOUND THEN
+        RETURN;
+    END IF;
+
+    INSERT INTO  dhcp4_client_class_order(class_id, order_index, depend_on_known_indirectly)
+        VALUES (id, follow_class_index + 1, 0);
+    RETURN;
+END;$$;
+
+-- -----------------------------------------------------------------------
+-- Trigger procedure to position an inserted class within the class hierarchy
+-- and create audit.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp4_client_class_AINS() RETURNS trigger AS $dhcp4_client_class_AINS$
+BEGIN
+    PERFORM setClientClass4Order(NEW.id, NEW.follow_class_name, NULL);
+    PERFORM createAuditEntryDHCP4('dhcp4_client_class', NEW.id, 'create');
+    RETURN NULL;
+END;
+$dhcp4_client_class_AINS$
+LANGUAGE plpgsql;
+
+-- Create dhcp4_client_class insert trigger
+CREATE TRIGGER dhcp4_client_class_AINS
+    AFTER INSERT ON dhcp4_client_class
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_client_class_AINS();
+
+-- -----------------------------------------------------------------------
+-- Trigger to position an updated class within the class hierarchy,
+-- create audit and remember the direct dependency on the
+-- KNOWN/UNKNOWN built-in classes before the class update.
+-- When updating a client class, it is very important to ensure that
+-- its dependency on KNOWN or UNKNOWN built-in client classes is not
+-- changed. It is because there may be other classes that depend on
+-- these built-ins via this class. Changing the dependency would break
+-- the chain of dependencies for other classes. Here, we store the
+-- information about the dependency in the session variables. Their
+-- values will be compared with the new dependencies after an update.
+-- If they change, an error will be signaled.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp4_client_class_AUPD() RETURNS trigger AS $dhcp4_client_class_AUPD$
+BEGIN
+    PERFORM set_session_value('kea.depend_on_known_directly', OLD.depend_on_known_directly);
+    PERFORM set_session_value('kea.client_class_id', NEW.id);
+    PERFORM setClientClass4Order(NEW.id, NEW.follow_class_name, OLD.follow_class_name);
+    PERFORM createAuditEntryDHCP4('dhcp4_client_class', NEW.id, 'update');
+    RETURN NULL;
+END;
+$dhcp4_client_class_AUPD$
+LANGUAGE plpgsql;
+
+-- Create dhcp4_client_class update insert trigger
+CREATE TRIGGER dhcp4_client_class_AUPD
+    AFTER UPDATE ON dhcp4_client_class
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_client_class_AUPD();
+
+-- -----------------------------------------------------------------------
+-- Trigger procedure to create the audit entry for client class delete.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp4_client_class_ADEL() RETURNS trigger AS $dhcp4_client_class_ADEL$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_client_class', OLD.id, 'delete');
+    RETURN NULL;
+END;
+$dhcp4_client_class_ADEL$
+LANGUAGE plpgsql;
+
+-- Create dhcp4_client_class delete trigger
+CREATE TRIGGER dhcp4_client_class_ADEL
+    AFTER DELETE ON dhcp4_client_class
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_client_class_ADEL();
+
+-- -----------------------------------------------------------------------
+-- Create a table associating client classes stored in the
+-- dhcp4_client_class table with their dependencies. There is
+-- an M:N relationship between these tables. Each class may have
+-- many dependencies (created using member operator in test expression),
+-- and each class may be a dependency for many other classes. A caller
+-- is responsible for inserting dependencies for a class after inserting
+-- or updating it in the dhcp4_client_class table. A caller should
+-- delete all existing dependencies for an updated client class, evaluate
+-- test expression to discover new dependencies (in case test expression
+-- has changed), and insert new dependencies to this table.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp4_client_class_dependency (
+    class_id BIGINT PRIMARY KEY NOT NULL,
+    dependency_id BIGINT NOT NULL,
+
+    CONSTRAINT dhcp4_client_class_class_id FOREIGN KEY (class_id)
+        REFERENCES dhcp4_client_class (id) ON DELETE CASCADE,
+    CONSTRAINT dhcp4_client_class_dependency_id FOREIGN KEY (dependency_id)
+        REFERENCES dhcp4_client_class (id)
+);
+
+CREATE INDEX dhcp4_client_class_dependency_id_idx on dhcp4_client_class_dependency (dependency_id);
+
+-- -----------------------------------------------------------------------
+-- Stored procedure verifying if class dependency is met. It includes
+-- checking if referenced classes exist, are associated with the same
+-- server or all servers, and are defined before the class specified with
+-- class_id.
+--
+-- Parameters:
+-- - p_class_id id client class,
+-- - p_dependency_id id of the dependency.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION checkDHCPv4ClientClassDependency(p_class_id BIGINT,
+                                                            p_dependency_id BIGINT)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    class_index BIGINT;
+    dependency_index BIGINT;
+BEGIN
+    -- We could check the same with a constraint but later in this
+    -- trigger we use this value to verify if the dependencies are
+    -- met.
+    IF p_class_id IS NULL THEN
+        RAISE EXCEPTION 'Client class id must not be NULL.'
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    IF p_dependency_id IS NULL THEN
+        RAISE EXCEPTION 'Class dependency id must not be NULL.'
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Dependencies on self make no sense.
+    IF p_class_id = p_dependency_id THEN
+        RAISE EXCEPTION 'Client class must not have dependency on self.'
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Check position of our class in the hierarchy.
+    SELECT o.order_index INTO class_index FROM dhcp4_client_class AS c
+        INNER JOIN dhcp4_client_class_order AS o ON c.id = o.class_id
+        WHERE c.id = p_class_id;
+
+    IF class_index IS NULL THEN
+        RAISE EXCEPTION 'Client class with id % does not exist.', p_class_id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Check position of the dependency.
+    SELECT o.order_index INTO dependency_index FROM dhcp4_client_class AS c
+        INNER JOIN dhcp4_client_class_order AS o ON c.id = o.class_id
+        WHERE c.id = p_dependency_id;
+
+    IF dependency_index IS NULL THEN
+        RAISE EXCEPTION 'Dependency class with id % does not exist.', p_dependency_id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- The dependency must not be later than our class.
+    IF dependency_index > class_index THEN
+        RAISE EXCEPTION
+            'Client class with id % must not depend on class defined later with id %',
+            p_class_id, p_dependency_id USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Check if all servers associated with the new class have dependent
+    -- classes configured. This catches the cases that class A belongs to
+    -- server1 and depends on class B which belongs only to server 2.
+    -- It is fine if the class B belongs to all servers in this case.
+    -- Make a SELECT on the dhcp4_client_class_server table to gather
+    -- all servers to which the class belongs. LEFT JOIN it with the
+    -- same table, selecting all records matching the dependency class
+    -- and the servers to which the new class belongs. If there are
+    -- any NULL records joined it implies that some dependencies are
+    -- not met (didn't find a dependency for at least one server).
+    IF EXISTS(
+        SELECT 1 FROM dhcp4_client_class_server AS t1
+            LEFT JOIN dhcp4_client_class_server AS t2
+                ON t2.class_id = p_dependency_id AND (t2.server_id = 1 OR t2.server_id = t1.server_id)
+        WHERE t1.class_id = p_class_id AND t2.server_id IS NULL
+        LIMIT 1
+    ) THEN
+        RAISE EXCEPTION 'Unmet dependencies for client class with id %', class_id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+    RETURN;
+END;$$;
+
+-- -----------------------------------------------------------------------
+-- Trigger verifying if class dependency is met. It includes checking
+-- if referenced classes exist, are associated with the same server
+-- or all servers, and are defined before the class specified with
+-- class_id.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp4_client_class_check_dependency_BINS()
+    RETURNS trigger AS $dhcp4_client_class_check_dependency_BINS$
+BEGIN
+    PERFORM checkDHCPv4ClientClassDependency(NEW.class_id, NEW.dependency_id);
+    RETURN NULL;
+END;
+$dhcp4_client_class_check_dependency_BINS$
+LANGUAGE plpgsql;
+
+-- Create dhcp4_client_class_check_dependency_BINS before insert trigger.
+CREATE TRIGGER dhcp4_client_class_check_dependency_BINS
+    BEFORE INSERT ON dhcp4_client_class_dependency
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_client_class_check_dependency_BINS();
+
+-- -----------------------------------------------------------------------
+-- Stored procedure setting client class indirect dependency on KNOWN or
+-- UNKNOWN built-in classes by checking this flag for the client classes
+-- on which it depends.
+--
+-- Parameters:
+-- - client_class_id id of the client class which dependency is set,
+-- - dependency_id id of the client class on which the given class depends.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION updateDHCPv4ClientClassKnownDependency(client_class_id BIGINT,
+                                                                  dependency_id BIGINT)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    dependency BOOLEAN;
+BEGIN
+    -- Check if the dependency class references KNOWN/UNKNOWN.
+    SELECT depend_on_known_directly INTO dependency FROM dhcp4_client_class
+        WHERE id = dependency_id;
+
+    -- If it doesn't, check if the dependency references KNOWN/UNKNOWN
+    -- indirectly (via other classes).
+    IF dependency = false THEN
+        SELECT depend_on_known_indirectly INTO dependency FROM dhcp4_client_class_order
+            WHERE class_id = dependency_id;
+    END IF;
+
+    IF dependency = true THEN
+        UPDATE dhcp4_client_class_order
+            SET depend_on_known_indirectly = true
+        WHERE class_id = client_class_id;
+    END IF;
+    RETURN;
+END;$$;
+
+-- -----------------------------------------------------------------------
+-- Trigger setting client class indirect dependency on KNOWN or UNKNOWN
+-- built-in classes by checking this flag for the client classes on which
+-- it depends.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp4_client_class_dependency_AINS()
+    RETURNS TRIGGER AS $dhcp4_client_class_dependency_AINS$
+BEGIN
+    PERFORM updateDHCPv4ClientClassKnownDependency(NEW.class_id, NEW.dependency_id);
+    RETURN NULL;
+END;
+$dhcp4_client_class_dependency_AINS$
+LANGUAGE plpgsql;
+
+-- Create dhcp4_client_class_check_dependency_AINS after insert trigger.
+CREATE TRIGGER dhcp4_client_class_dependency_AINS
+    AFTER INSERT ON dhcp4_client_class_dependency
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_client_class_dependency_AINS();
+
+-- -----------------------------------------------------------------------
+-- Stored procedure to be executed before committing a transaction
+-- updating a DHCPv4 client class. It verifies if the class dependency on
+-- KNOWN or UNKNOWN built-in classes has changed as a result of the
+-- update. It signals an error if it has changed and there is at least
+-- one class depending on this class.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION checkDHCPv4ClientClassKnownDependencyChange()
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    depended BOOLEAN := false;
+    depends BOOLEAN := false;
+    client_class_id BIGINT;
+    depend_on_known_directly BOOLEAN;
+    depend_on_known_indirectly BOOLEAN;
+BEGIN
+
+    -- Session variables are set upon a client class update.
+    client_class_id := get_session_big_int('kea.client_class_id');
+    IF client_class_id IS NOT NULL THEN
+        -- Check if any of the classes depend on this class. If not,
+        -- it is ok to change the dependency on KNOWN/UNKNOWN.
+        IF EXISTS(
+            SELECT 1 FROM dhcp4_client_class_dependency
+            WHERE dependency_id = client_class_id LIMIT 1
+        ) THEN
+            -- Using the session variables, determine whether the client class
+            -- depended on KNOWN/UNKNOWN before the update.
+            depend_on_known_directly := get_session_boolean('kea.depend_on_known_directly');
+            depend_on_known_indirectly := get_session_boolean('kea.depend_on_known_indirectly');
+            IF depend_on_known_directly = true OR depend_on_known_indirectly = true THEN
+                SET depended = true;
+            END IF;
+
+            -- Check if the client class depends on KNOWN/UNKNOWN after the update.
+            SELECT depend_on_known_directly INTO depends FROM dhcp4_client_class
+                WHERE id = client_class_id;
+
+            -- If it doesn't depend directly, check indirect dependencies.
+            IF depends = false THEN
+                SELECT depend_on_known_indirectly INTO depends FROM dhcp4_client_class_order
+                    WHERE class_id = client_class_id;
+            END IF;
+
+            -- The resulting dependency on KNOWN/UNKNOWN must not change.
+            IF depended <> depends THEN
+                RAISE EXCEPTION 'Class dependency on KNOWN/UNKNOWN built-in classes must not change.'
+                    USING ERRCODE = 'sql_routine_exception';
+            END IF;
+        END IF;
+    END IF;
+    RETURN;
+END;$$;
+
+-- -----------------------------------------------------------------------
+-- Create table matching DHCPv4 classes with the servers.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp4_client_class_server (
+    class_id BIGINT NOT NULL,
+    server_id BIGINT NOT NULL,
+    modification_ts  TIMESTAMP WITH TIME ZONE NULL DEFAULT NULL,
+    PRIMARY KEY (class_id,server_id),
+    CONSTRAINT fk_dhcp4_client_class_class_id FOREIGN KEY (class_id)
+        REFERENCES dhcp4_client_class (id)
+        ON DELETE CASCADE,
+    CONSTRAINT fk_dhcp4_client_class_server_id FOREIGN KEY (server_id)
+        REFERENCES dhcp4_server (id)
+);
+
+CREATE INDEX fk_dhcp4_client_class_server_id ON dhcp4_client_class_server (server_id);
+
+-- -----------------------------------------------------
+-- Stored procedure which creates a new entry in the
+-- dhcp6_audit_revision table and sets appropriate session
+-- variables to be used while creating the audit entries
+-- by triggers. This procedure should be called at the
+-- beginning of a transaction which modifies configuration
+-- data in the database, e.g. when new subnet is added.
+--
+-- Parameters:
+-- - audit_ts timestamp to be associated with the audit
+--   revision.
+-- - server_tag is used to retrieve the server_id which
+--   associates the changes applied with the particular
+--   server or all servers.
+-- - audit_log_message is a log message associates with
+--   the audit revision.
+-- - cascade_transaction is assigned to a session
+--   variable which is used in some triggers to determine
+--   if the audit entry should be created for them or
+--   not. Specifically, this is used when DHCP options
+--   are inserted, updated or deleted. If such modification
+--   is a part of the larger change (e.g. change in the
+--   subnet the options belong to) the dedicated audit
+--   entry for options must not be created. On the other
+--   hand, if the global option is being added, the
+--   audit entry for the option must be created because
+--   it is the sole object modified in that case.
+--   Session variable disable_audit is used to disable
+--   the procedure when wiping the database during
+--   unit tests.  This avoids issues with revision_id
+--   being null.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createAuditRevisionDHCP6(audit_ts TIMESTAMP WITH TIME ZONE,
+                                                    server_tag VARCHAR(64),
+                                                    audit_log_message TEXT,
+                                                    cascade_transaction BOOLEAN)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    disable_audit BOOLEAN := false;
+    audit_revision_id BIGINT;
+    srv_id BIGINT;
+BEGIN
+    -- Fetch session value for disable_audit.
+    disable_audit := get_session_boolean('kea.disable_audit');
+    IF disable_audit = false THEN
+        SELECT id INTO srv_id FROM dhcp6_server WHERE tag = server_tag;
+        INSERT INTO dhcp6_audit_revision (modification_ts, server_id, log_message)
+            VALUES (audit_ts, srv_id, audit_log_message) returning id INTO audit_revision_id;
+
+        -- Update pertinent session variables.
+        PERFORM set_session_value('kea.audit_revision_id', audit_revision_id);
+        PERFORM set_session_value('kea.cascade_transaction', cascade_transaction);
+    END IF;
+    RETURN;
+END;$$;
+
+-- -----------------------------------------------------
+-- Stored procedure which creates a new entry in the
+-- dhcp6_audit table. It should be called from the
+-- triggers of the tables where the config modifications
+-- are applied. The audit_revision_id variable contains
+-- the revision id to be placed in the audit entries.
+--
+-- The following parameters are passed to this procedure:
+-- - object_type_val: name of the table to be associated
+--   with the applied changes.
+-- - object_id_val: identifier of the modified object in
+--   that table.
+-- - modification_type_val: string value indicating the
+--   type of the change, i.e. 'create', 'update' or
+--   'delete'.
+--   Session variable disable_audit is used to disable
+--   the procedure when wiping the database during
+--   unit tests.  This avoids issues with revision_id
+--   being null.
+-- ----------------------------------------------------
+CREATE OR REPLACE FUNCTION createAuditEntryDHCP6(object_type_val VARCHAR(256),
+                                                 object_id_val BIGINT,
+                                                 modification_type_val VARCHAR(32))
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    audit_revision_id BIGINT;
+    disable_audit BOOLEAN := false;
+BEGIN
+    -- Fetch session value for disable_audit.
+    disable_audit := get_session_boolean('kea.disable_audit');
+    IF disable_audit = false THEN
+        -- Fetch session value most recently created audit_revision_id.
+        audit_revision_id := get_session_big_int('kea.audit_revision_id');
+        INSERT INTO dhcp6_audit (object_type, object_id, modification_type, revision_id)
+            VALUES (object_type_val, object_id_val,
+                (SELECT id FROM modification WHERE modification_type = modification_type_val),
+                 audit_revision_id);
+    END IF;
+    RETURN;
+END;$$;
+
+-- -----------------------------------------------------------------------
+-- Create a table holding the DHCPv6 client classes. Most table
+-- columns map directly to respective client class properties in
+-- Kea configuration. The depend_on_known_directly column is
+-- explicitly set in an insert or update statement to indicate
+-- if the client class directly depends on KNOWN or UNKNOWN
+-- built-in classes. A caller should determine it by evaluating
+-- a test expression before inserting or updating the client
+-- class in the database. The nullable follow_class_name column
+-- can be used for positioning the inserted or updated client
+-- class within the class hierarchy. Set this column value to
+-- an existing class name, after which this class should be
+-- placed in the class hierarchy. See dhcp6_client_class_order
+-- description for the details of how classes are ordered.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp6_client_class (
+    id SERIAL PRIMARY KEY NOT NULL,
+    name VARCHAR(128) UNIQUE NOT NULL,
+    test TEXT,
+    only_if_required BOOLEAN NOT NULL DEFAULT false,
+    valid_lifetime BIGINT DEFAULT NULL,
+    min_valid_lifetime BIGINT DEFAULT NULL,
+    max_valid_lifetime BIGINT DEFAULT NULL,
+    depend_on_known_directly BOOLEAN NOT NULL DEFAULT false,
+    follow_class_name VARCHAR(128) DEFAULT NULL,
+    modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE INDEX key_dhcp6_client_class_modification_ts on dhcp6_client_class (modification_ts);
+
+-- -----------------------------------------------------------------------
+-- Create a table for ordering client classes and holding information
+-- about indirect dependencies on KNOWN/UKNOWN built-in client classes.
+-- Each class in the dhcp6_client_class table has a corresponding row
+-- in the dhcp6_client_class_order table. A caller should not modify
+-- the contents of this table. Its entries are automatically created
+-- upon inserting or updating client classes in the dhcp6_client_classes
+-- using triggers. The order_index designates the position of the client
+-- class within the class hierarchy. If the follow_class_name value of
+-- the dhcp6_client_class table is set to NULL, the client class is
+-- appended at the end of the hierarchy. The assigned order_index
+-- value for that class is set to a maximum current value + 1.
+-- If the follow_client_class specifies a name of an existing class,
+-- the generated order_index is set to an id of that class + 1, and
+-- the order_index values of the later classes are incremented by 1.
+-- The depend_on_known_indirectly column holds a boolean value indicating
+-- whether the given class depends on KNOWN/UKNOWN built-in classes
+-- via other classes, i.e. it depends on classes that directly or
+-- indirectly depend on these built-ins. This value is auto-generated
+-- by a trigger on the dhcp6_client_class_dependency table.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp6_client_class_order (
+    class_id BIGINT PRIMARY KEY NOT NULL,
+    order_index BIGINT NOT NULL,
+    depend_on_known_indirectly BOOLEAN NOT NULL DEFAULT false,
+    CONSTRAINT fk_dhcp6_client_class_order_class_id FOREIGN KEY (class_id)
+        REFERENCES dhcp6_client_class (id) ON DELETE CASCADE
+);
+
+CREATE INDEX key_dhcp6_client_class_order_index on dhcp6_client_class_order (order_index);
+
+-- -----------------------------------------------------------------------
+-- Stored procedure positioning an inserted or updated client class
+-- within the class hierarchy, depending on the value of the
+-- new_follow_class_name parameter.
+--
+-- Parameters:
+-- - id id of the positioned class,
+-- - new_follow_class_name name of the class after which this class should be
+--   positioned within the class hierarchy.
+-- - old_follow_class_name previous name of the class after which this
+--   class was positioned within the class hierarchy.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION setClientClass6Order(id BIGINT,
+                                                new_follow_class_name VARCHAR(128),
+                                                old_follow_class_name VARCHAR(128))
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    -- Used to fetch class's current value for depend_on_known_indirectly
+    l_depend_on_known_indirectly BIGINT := 0;
+
+    -- Optionally set if the follow_class_name column value is specified.
+    follow_class_index BIGINT;
+BEGIN
+    -- Fetch the class's current value of depend_on_known_indirectly.
+    SELECT depend_on_known_indirectly INTO l_depend_on_known_indirectly
+        FROM dhcp6_client_class_order WHERE id = class_id;
+
+    -- Save it to the current session for use elsewhere during this transaction.
+    -- Note this does not work prior to Postgres 9.2 unless the variables are
+    -- defined in postgresql.conf. I think for now we put up with CB not supported
+    -- prior to 9.2 or we tell people how to edit the conf file.
+    PERFORM set_session_value('kea.depend_on_known_indirectly', l_depend_on_known_indirectly);
+
+    -- Bail if the class is updated without re-positioning.
+    IF(
+       l_depend_on_known_indirectly IS NOT NULL AND
+       ((new_follow_class_name IS NULL AND old_follow_class_name IS NULL) OR
+        (new_follow_class_name = old_follow_class_name))
+    ) THEN
+        -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+        -- whenever the dhcp6_client_class record is updated. Such update may include
+        -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+        -- This value will be later adjusted when dependencies are inserted.
+        -- TKM should we update the session value also or is it moot?
+        UPDATE dhcp6_client_class_order SET depend_on_known_indirectly = false
+            WHERE class_id = id;
+        RETURN;
+    END IF;
+
+    IF new_follow_class_name IS NOT NULL THEN
+        -- Get the position of the class after which the new class should be added.
+        SELECT o.order_index INTO follow_class_index
+            FROM dhcp6_client_class AS c
+            INNER JOIN dhcp6_client_class_order AS o
+                ON c.id = o.class_id
+            WHERE c.name = new_follow_class_name;
+
+        IF follow_class_index IS NULL THEN
+            -- The class with a name specified with new_follow_class_name does
+            -- not exist.
+            RAISE EXCEPTION 'Class %s does not exist.', new_follow_class_name
+                USING ERRCODE = 'sql_routine_exception';
+        END IF;
+
+        -- We need to place the new class at the position of follow_class_index + 1.
+        -- There may be a class at this position already.
+        IF EXISTS(SELECT * FROM dhcp6_client_class_order WHERE order_index = follow_class_index + 1) THEN
+            -- There is a class at this position already. Let's move all classes
+            -- starting from this position by one to create a spot for the new
+            -- class.
+            UPDATE dhcp6_client_class_order
+                SET order_index = order_index + 1
+            WHERE order_index >= follow_class_index + 1;
+            -- TKM postgresql doesn't like order by here, does it matter?
+            -- ORDER BY order_index DESC;
+        END IF;
+
+    ELSE
+        -- A caller did not specify the new_follow_class_name value. Let's append the
+        -- new class at the end of the hierarchy.
+        SELECT MAX(order_index) INTO follow_class_index FROM dhcp6_client_class_order;
+        IF follow_class_index IS NULL THEN
+            -- Apparently, there are no classes. Let's start from 0.
+            follow_class_index = 0;
+        END IF;
+    END IF;
+
+    -- Check if moving the class doesn't break dependent classes.
+    IF EXISTS(
+        SELECT 1 FROM dhcp6_client_class_dependency AS d
+            INNER JOIN dhcp6_client_class_order AS o
+                ON d.class_id = o.class_id
+            WHERE d.dependency_id = id AND o.order_index < follow_class_index + 1
+        LIMIT 1
+    ) THEN
+        RAISE EXCEPTION 'Unable to move class with id %s because it would break its dependencies', id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+    -- whenever the dhcp6_client_class record is updated. Such update may include
+    -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+    -- This value will be later adjusted when dependencies are inserted.
+    -- TKM - note that ON CONFLICT requires PostgreSQL 9.5 or later.
+    UPDATE dhcp6_client_class_order
+        SET order_index = follow_class_index + 1,
+            depend_on_known_indirectly = l_depend_on_known_indirectly
+        WHERE class_id = id;
+    IF FOUND THEN
+        RETURN;
+    END IF;
+
+    INSERT INTO  dhcp6_client_class_order(class_id, order_index, depend_on_known_indirectly)
+        VALUES (id, follow_class_index + 1, 0);
+    RETURN;
+END;$$;
+
+-- -----------------------------------------------------------------------
+-- Trigger procedure to position an inserted class within the class hierarchy
+-- and create audit.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp6_client_class_AINS() RETURNS trigger AS $dhcp6_client_class_AINS$
+BEGIN
+    PERFORM setClientClass6Order(NEW.id, NEW.follow_class_name, NULL);
+    PERFORM createAuditEntryDHCP6('dhcp6_client_class', NEW.id, 'create');
+    RETURN NULL;
+END;
+$dhcp6_client_class_AINS$
+LANGUAGE plpgsql;
+
+-- Create dhcp6_client_class insert trigger
+CREATE TRIGGER dhcp6_client_class_AINS
+    AFTER INSERT ON dhcp6_client_class
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_client_class_AINS();
+
+-- -----------------------------------------------------------------------
+-- Trigger to position an updated class within the class hierarchy,
+-- create audit and remember the direct dependency on the
+-- KNOWN/UNKNOWN built-in classes before the class update.
+-- When updating a client class, it is very important to ensure that
+-- its dependency on KNOWN or UNKNOWN built-in client classes is not
+-- changed. It is because there may be other classes that depend on
+-- these built-ins via this class. Changing the dependency would break
+-- the chain of dependencies for other classes. Here, we store the
+-- information about the dependency in the session variables. Their
+-- values will be compared with the new dependencies after an update.
+-- If they change, an error will be signaled.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp6_client_class_AUPD() RETURNS trigger AS $dhcp6_client_class_AUPD$
+BEGIN
+    PERFORM set_session_value('kea.depend_on_known_directly', OLD.depend_on_known_directly);
+    PERFORM set_session_value('kea.client_class_id', NEW.id);
+    PERFORM setClientClass6Order(NEW.id, NEW.follow_class_name, OLD.follow_class_name);
+    PERFORM createAuditEntryDHCP6('dhcp6_client_class', NEW.id, 'update');
+    RETURN NULL;
+END;
+$dhcp6_client_class_AUPD$
+LANGUAGE plpgsql;
+
+-- Create dhcp6_client_class update insert trigger
+CREATE TRIGGER dhcp6_client_class_AUPD
+    AFTER UPDATE ON dhcp6_client_class
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_client_class_AUPD();
+
+-- -----------------------------------------------------------------------
+-- Trigger procedure to create the audit entry for client class delete.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp6_client_class_ADEL() RETURNS trigger AS $dhcp6_client_class_ADEL$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_client_class', OLD.id, 'delete');
+    RETURN NULL;
+END;
+$dhcp6_client_class_ADEL$
+LANGUAGE plpgsql;
+
+-- Create dhcp6_client_class delete trigger
+CREATE TRIGGER dhcp6_client_class_ADEL
+    AFTER DELETE ON dhcp6_client_class
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_client_class_ADEL();
+
+-- -----------------------------------------------------------------------
+-- Create a table associating client classes stored in the
+-- dhcp6_client_class table with their dependencies. There is
+-- an M:N relationship between these tables. Each class may have
+-- many dependencies (created using member operator in test expression),
+-- and each class may be a dependency for many other classes. A caller
+-- is responsible for inserting dependencies for a class after inserting
+-- or updating it in the dhcp6_client_class table. A caller should
+-- delete all existing dependencies for an updated client class, evaluate
+-- test expression to discover new dependencies (in case test expression
+-- has changed), and insert new dependencies to this table.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp6_client_class_dependency (
+    class_id BIGINT PRIMARY KEY NOT NULL,
+    dependency_id BIGINT NOT NULL,
+
+    CONSTRAINT dhcp6_client_class_class_id FOREIGN KEY (class_id)
+        REFERENCES dhcp6_client_class (id) ON DELETE CASCADE,
+    CONSTRAINT dhcp6_client_class_dependency_id FOREIGN KEY (dependency_id)
+        REFERENCES dhcp6_client_class (id)
+);
+
+CREATE INDEX dhcp6_client_class_dependency_id_idx on dhcp6_client_class_dependency (dependency_id);
+
+-- -----------------------------------------------------------------------
+-- Stored procedure verifying if class dependency is met. It includes
+-- checking if referenced classes exist, are associated with the same
+-- server or all servers, and are defined before the class specified with
+-- class_id.
+--
+-- Parameters:
+-- - p_class_id id client class,
+-- - p_dependency_id id of the dependency.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION checkDHCPv6ClientClassDependency(p_class_id BIGINT,
+                                                            p_dependency_id BIGINT)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    class_index BIGINT;
+    dependency_index BIGINT;
+BEGIN
+    -- We could check the same with a constraint but later in this
+    -- trigger we use this value to verify if the dependencies are
+    -- met.
+    IF p_class_id IS NULL THEN
+        RAISE EXCEPTION 'Client class id must not be NULL.'
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    IF p_dependency_id IS NULL THEN
+        RAISE EXCEPTION 'Class dependency id must not be NULL.'
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Dependencies on self make no sense.
+    IF p_class_id = p_dependency_id THEN
+        RAISE EXCEPTION 'Client class must not have dependency on self.'
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Check position of our class in the hierarchy.
+    SELECT o.order_index INTO class_index FROM dhcp6_client_class AS c
+        INNER JOIN dhcp6_client_class_order AS o ON c.id = o.class_id
+        WHERE c.id = p_class_id;
+
+    IF class_index IS NULL THEN
+        RAISE EXCEPTION 'Client class with id % does not exist.', p_class_id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Check position of the dependency.
+    SELECT o.order_index INTO dependency_index FROM dhcp6_client_class AS c
+        INNER JOIN dhcp6_client_class_order AS o ON c.id = o.class_id
+        WHERE c.id = p_dependency_id;
+
+    IF dependency_index IS NULL THEN
+        RAISE EXCEPTION 'Dependency class with id % does not exist.', p_dependency_id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- The dependency must not be later than our class.
+    IF dependency_index > class_index THEN
+        RAISE EXCEPTION
+            'Client class with id % must not depend on class defined later with id %',
+            p_class_id, p_dependency_id USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Check if all servers associated with the new class have dependent
+    -- classes configured. This catches the cases that class A belongs to
+    -- server1 and depends on class B which belongs only to server 2.
+    -- It is fine if the class B belongs to all servers in this case.
+    -- Make a SELECT on the dhcp6_client_class_server table to gather
+    -- all servers to which the class belongs. LEFT JOIN it with the
+    -- same table, selecting all records matching the dependency class
+    -- and the servers to which the new class belongs. If there are
+    -- any NULL records joined it implies that some dependencies are
+    -- not met (didn't find a dependency for at least one server).
+    IF EXISTS(
+        SELECT 1 FROM dhcp6_client_class_server AS t1
+            LEFT JOIN dhcp6_client_class_server AS t2
+                ON t2.class_id = p_dependency_id AND (t2.server_id = 1 OR t2.server_id = t1.server_id)
+        WHERE t1.class_id = p_class_id AND t2.server_id IS NULL
+        LIMIT 1
+    ) THEN
+        RAISE EXCEPTION 'Unmet dependencies for client class with id %', p_class_id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+    RETURN;
+END;$$;
+
+-- -----------------------------------------------------------------------
+-- Trigger verifying if class dependency is met. It includes checking
+-- if referenced classes exist, are associated with the same server
+-- or all servers, and are defined before the class specified with
+-- class_id.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp6_client_class_check_dependency_BINS()
+    RETURNS trigger AS $dhcp6_client_class_check_dependency_BINS$
+BEGIN
+    PERFORM checkDHCPv6ClientClassDependency(NEW.class_id, NEW.dependency_id);
+    RETURN NULL;
+END;
+$dhcp6_client_class_check_dependency_BINS$
+LANGUAGE plpgsql;
+
+-- Create dhcp6_client_class_check_dependency_BINS before insert trigger.
+CREATE TRIGGER dhcp6_client_class_check_dependency_BINS
+    BEFORE INSERT ON dhcp6_client_class_dependency
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_client_class_check_dependency_BINS();
+
+-- -----------------------------------------------------------------------
+-- Stored procedure setting client class indirect dependency on KNOWN or
+-- UNKNOWN built-in classes by checking this flag for the client classes
+-- on which it depends.
+--
+-- Parameters:
+-- - client_class_id id of the client class which dependency is set,
+-- - dependency_id id of the client class on which the given class depends.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION updateDHCPv6ClientClassKnownDependency(client_class_id BIGINT,
+                                                                  dependency_id BIGINT)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    dependency BOOLEAN;
+BEGIN
+    -- Check if the dependency class references KNOWN/UNKNOWN.
+    SELECT depend_on_known_directly INTO dependency FROM dhcp6_client_class
+        WHERE id = dependency_id;
+
+    -- If it doesn't, check if the dependency references KNOWN/UNKNOWN
+    -- indirectly (via other classes).
+    IF dependency = false THEN
+        SELECT depend_on_known_indirectly INTO dependency FROM dhcp6_client_class_order
+            WHERE class_id = dependency_id;
+    END IF;
+
+    IF dependency = true THEN
+        UPDATE dhcp6_client_class_order
+            SET depend_on_known_indirectly = true
+        WHERE class_id = client_class_id;
+    END IF;
+    RETURN;
+END;$$;
+
+-- -----------------------------------------------------------------------
+-- Trigger setting client class indirect dependency on KNOWN or UNKNOWN
+-- built-in classes by checking this flag for the client classes on which
+-- it depends.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp6_client_class_dependency_AINS()
+    RETURNS TRIGGER AS $dhcp6_client_class_dependency_AINS$
+BEGIN
+    PERFORM updateDHCPv6ClientClassKnownDependency(NEW.class_id, NEW.dependency_id);
+    RETURN NULL;
+END;
+$dhcp6_client_class_dependency_AINS$
+LANGUAGE plpgsql;
+
+-- Create dhcp6_client_class_check_dependency_AINS after insert trigger.
+CREATE TRIGGER dhcp6_client_class_dependency_AINS
+    AFTER INSERT ON dhcp6_client_class_dependency
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_client_class_dependency_AINS();
+
+-- -----------------------------------------------------------------------
+-- Stored procedure to be executed before committing a transaction
+-- updating a DHCPv6 client class. It verifies if the class dependency on
+-- KNOWN or UNKNOWN built-in classes has changed as a result of the
+-- update. It signals an error if it has changed and there is at least
+-- one class depending on this class.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION checkDHCPv6ClientClassKnownDependencyChange()
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    depended BOOLEAN := false;
+    depends BOOLEAN := false;
+    client_class_id BIGINT;
+    depend_on_known_directly BOOLEAN;
+    depend_on_known_indirectly BOOLEAN;
+BEGIN
+
+    -- Session variables are set upon a client class update.
+    client_class_id := get_session_big_int('kea.client_class_id');
+    IF client_class_id IS NOT NULL THEN
+        -- Check if any of the classes depend on this class. If not,
+        -- it is ok to change the dependency on KNOWN/UNKNOWN.
+        IF EXISTS(
+            SELECT 1 FROM dhcp6_client_class_dependency
+            WHERE dependency_id = client_class_id LIMIT 1
+        ) THEN
+            -- Using the session variables, determine whether the client class
+            -- depended on KNOWN/UNKNOWN before the update.
+            depend_on_known_directly := get_session_boolean('kea.depend_on_known_directly');
+            depend_on_known_indirectly := get_session_boolean('kea.depend_on_known_indirectly');
+            IF depend_on_known_directly = true OR depend_on_known_indirectly = true THEN
+                SET depended = true;
+            END IF;
+
+            -- Check if the client class depends on KNOWN/UNKNOWN after the update.
+            SELECT depend_on_known_directly INTO depends FROM dhcp6_client_class
+                WHERE id = client_class_id;
+
+            -- If it doesn't depend directly, check indirect dependencies.
+            IF depends = false THEN
+                SELECT depend_on_known_indirectly INTO depends FROM dhcp6_client_class_order
+                    WHERE class_id = client_class_id;
+            END IF;
+
+            -- The resulting dependency on KNOWN/UNKNOWN must not change.
+            IF depended <> depends THEN
+                RAISE EXCEPTION 'Class dependency on KNOWN/UNKNOWN built-in classes must not change.'
+                    USING ERRCODE = 'sql_routine_exception';
+            END IF;
+        END IF;
+    END IF;
+    RETURN;
+END;$$;
+
+-- -----------------------------------------------------------------------
+-- Create table matching DHCPv6 classes with the servers.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp6_client_class_server (
+    class_id BIGINT NOT NULL,
+    server_id BIGINT NOT NULL,
+    modification_ts  TIMESTAMP WITH TIME ZONE NULL DEFAULT NULL,
+    PRIMARY KEY (class_id,server_id),
+    CONSTRAINT fk_dhcp6_client_class_class_id FOREIGN KEY (class_id)
+        REFERENCES dhcp6_client_class (id)
+        ON DELETE CASCADE,
+    CONSTRAINT fk_dhcp6_client_class_server_id FOREIGN KEY (server_id)
+        REFERENCES dhcp6_server (id)
+);
+
+CREATE INDEX fk_dhcp6_client_class_server_id ON dhcp6_client_class_server (server_id);
+
+-- Trigger function for dhcp4_pool_BDEL called BEFORE DELETE on dhcp4_pool
+-- It removes pool specific options upon removal of the pool.
+CREATE OR REPLACE FUNCTION func_dhcp4_pool_BDEL() RETURNS TRIGGER AS $dhcp4_pool_BDEL$
+BEGIN
+    DELETE FROM dhcp4_options WHERE scope_id = 5 AND pool_id = OLD.id;
+    RETURN OLD;
+END;
+$dhcp4_pool_BDEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_pool_BDEL
+    BEFORE DELETE ON dhcp4_pool
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_pool_BDEL();
+
+-- Trigger function for dhcp6_pool_BDEL called BEFORE DELETE on dhcp6_pool
+-- It removes pool specific options upon removal of the pool.
+CREATE OR REPLACE FUNCTION func_dhcp6_pool_BDEL() RETURNS TRIGGER AS $dhcp6_pool_BDEL$
+BEGIN
+    DELETE FROM dhcp6_options WHERE scope_id = 5 AND pool_id = OLD.id;
+    RETURN OLD;
+END;
+$dhcp6_pool_BDEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_pool_BDEL
+    BEFORE DELETE ON dhcp6_pool
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_pool_BDEL();
+
+-- Trigger function for dhcp4_global_parameter_AINS called AFTER INSERT on dhcp4_global_parameter
+CREATE OR REPLACE FUNCTION func_dhcp4_global_parameter_AINS() RETURNS TRIGGER AS $dhcp4_global_parameter_AINS$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_global_parameter', NEW.id, 'create');
+    RETURN NULL;
+END;
+$dhcp4_global_parameter_AINS$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_global_parameter_AINS
+    AFTER INSERT ON dhcp4_global_parameter
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_global_parameter_AINS();
+
+-- Trigger function for dhcp4_global_parameter_AUPD called AFTER UPDATE on dhcp4_global_parameter
+CREATE OR REPLACE FUNCTION func_dhcp4_global_parameter_AUPD() RETURNS TRIGGER AS $dhcp4_global_parameter_AUPD$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_global_parameter', NEW.id, 'update');
+    RETURN NULL;
+END;
+$dhcp4_global_parameter_AUPD$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_global_parameter_AUPD
+    AFTER UPDATE ON dhcp4_global_parameter
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_global_parameter_AUPD();
+
+-- Trigger function for dhcp4_global_parameter_ADEL called AFTER DELETE on dhcp4_global_parameter
+CREATE OR REPLACE FUNCTION func_dhcp4_global_parameter_ADEL() RETURNS TRIGGER AS $dhcp4_global_parameter_ADEL$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_global_parameter', OLD.id, 'delete');
+    RETURN NULL;
+END;
+$dhcp4_global_parameter_ADEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_global_parameter_ADEL
+    AFTER DELETE ON dhcp4_global_parameter
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_global_parameter_ADEL();
+
+-- Trigger function for dhcp4_subnet_AINS called AFTER INSERT on dhcp4_subnet
+CREATE OR REPLACE FUNCTION func_dhcp4_subnet_AINS() RETURNS TRIGGER AS $dhcp4_subnet_AINS$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_subnet', NEW.subnet_id, 'create');
+    RETURN NULL;
+END;
+$dhcp4_subnet_AINS$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_subnet_AINS
+    AFTER INSERT ON dhcp4_subnet
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_subnet_AINS();
+
+-- Trigger function for dhcp4_subnet_AUPD called AFTER UPDATE on dhcp4_subnet
+CREATE OR REPLACE FUNCTION func_dhcp4_subnet_AUPD() RETURNS TRIGGER AS $dhcp4_subnet_AUPD$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_subnet', NEW.subnet_id, 'update');
+    RETURN NULL;
+END;
+$dhcp4_subnet_AUPD$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_subnet_AUPD
+    AFTER UPDATE ON dhcp4_subnet
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_subnet_AUPD();
+
+-- Trigger function for dhcp4_shared_network_AINS called AFTER INSERT on dhcp4_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp4_shared_network_AINS() RETURNS TRIGGER AS $dhcp4_shared_network_AINS$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_shared_network', NEW.id, 'create');
+    RETURN NULL;
+END;
+$dhcp4_shared_network_AINS$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_shared_network_AINS
+    AFTER INSERT ON dhcp4_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_shared_network_AINS();
+
+-- Trigger function for dhcp4_shared_network_AUPD called AFTER UPDATE on dhcp4_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp4_shared_network_AUPD() RETURNS TRIGGER AS $dhcp4_shared_network_AUPD$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_shared_network', NEW.id, 'update');
+    RETURN NULL;
+END;
+$dhcp4_shared_network_AUPD$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_shared_network_AUPD
+    AFTER UPDATE ON dhcp4_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_shared_network_AUPD();
+
+-- Trigger function for dhcp4_shared_network_ADEL called AFTER DELETE on dhcp4_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp4_shared_network_ADEL() RETURNS TRIGGER AS $dhcp4_shared_network_ADEL$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_shared_network', OLD.id, 'delete');
+    RETURN NULL;
+END;
+$dhcp4_shared_network_ADEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_shared_network_ADEL
+    AFTER DELETE ON dhcp4_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_shared_network_ADEL();
+
+-- Trigger function for dhcp4_option_def_AINS called AFTER INSERT on dhcp4_option_def
+CREATE OR REPLACE FUNCTION func_dhcp4_option_def_AINS() RETURNS TRIGGER AS $dhcp4_option_def_AINS$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_option_def', NEW.id, 'create');
+    RETURN NULL;
+END;
+$dhcp4_option_def_AINS$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_option_def_AINS
+    AFTER INSERT ON dhcp4_option_def
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_option_def_AINS();
+
+-- Trigger function for dhcp4_option_def_AUPD called AFTER UPDATE on dhcp4_option_def
+CREATE OR REPLACE FUNCTION func_dhcp4_option_def_AUPD() RETURNS TRIGGER AS $dhcp4_option_def_AUPD$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_option_def', NEW.id, 'update');
+    RETURN NULL;
+END;
+$dhcp4_option_def_AUPD$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_option_def_AUPD
+    AFTER UPDATE ON dhcp4_option_def
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_option_def_AUPD();
+
+-- Trigger function for dhcp4_option_def_ADEL called AFTER DELETE on dhcp4_option_def
+CREATE OR REPLACE FUNCTION func_dhcp4_option_def_ADEL() RETURNS TRIGGER AS $dhcp4_option_def_ADEL$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_option_def', OLD.id, 'delete');
+    RETURN NULL;
+END;
+$dhcp4_option_def_ADEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_option_def_ADEL
+    AFTER DELETE ON dhcp4_option_def
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_option_def_ADEL();
+
+-- -----------------------------------------------------
+--
+-- Stored procedure which updates modification timestamp of
+-- a parent object when an option is modified.
+--
+-- The following parameters are passed to the procedure:
+-- - modification_type: 'create', 'update' or 'delete'
+-- - scope_id: identifier of the option scope, e.g.
+--   global, subnet specific etc.
+-- - option_id: identifier of the option.
+-- - p_subnet_id: identifier of the subnet if the option
+--   belongs to the subnet.
+-- - host_id: identifier of the host if the option
+-- - belongs to the host.
+-- - network_name: shared network name if the option
+--   belongs to the shared network.
+-- - pool_id: identifier of the pool if the option
+--   belongs to the pool.
+-- - p_modification_ts: modification timestamp of the
+--   option.
+--   Some arguments are prefixed with "p_" to avoid ambiguity
+--   with column names in SQL statements. PostgreSQL does not
+--   allow table aliases to be used with column names in update
+--   set expressions.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createOptionAuditDHCP4(modification_type VARCHAR,
+                                                  scope_id SMALLINT,
+                                                  option_id INT,
+                                                  p_subnet_id BIGINT,
+                                                  host_id INT,
+                                                  network_name VARCHAR,
+                                                  pool_id BIGINT,
+                                                  p_modification_ts TIMESTAMP WITH TIME ZONE)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    -- These variables will hold shared network id and subnet id that
+    -- we will select.
+    snid VARCHAR(128);
+    sid BIGINT;
+    cascade_transaction BOOLEAN := true;
+    ct TEXT;
+BEGIN
+    -- Cascade transaction flag is set to true to prevent creation of
+    -- the audit entries for the options when the options are
+    -- created as part of the parent object creation or update.
+    -- For example: when the option is added as part of the subnet
+    -- addition, the cascade transaction flag is equal to true. If
+    -- the option is added into the existing subnet the cascade
+    -- transaction is equal to false. Note that depending on the option
+    -- scope the audit entry will contain the object_type value
+    -- of the parent object to cause the server to replace the
+    -- entire subnet. The only case when the object_type will be
+    -- set to 'dhcp4_options' is when a global option is added.
+    -- Global options do not have the owner.
+
+    cascade_transaction := get_session_boolean('kea.cascade_transaction');
+    IF cascade_transaction = false THEN
+        -- todo: host manager hasn't been updated to use audit
+        -- mechanisms so ignore host specific options for now.
+        IF scope_id = 0 THEN
+            -- If a global option is added or modified, create audit
+            -- entry for the 'dhcp4_options' table.
+            PERFORM createAuditEntryDHCP4('dhcp4_options', option_id, modification_type);
+        ELSEIF scope_id = 1 THEN
+            -- If subnet specific option is added or modified, update
+            -- the modification timestamp of this subnet to allow the
+            -- servers to refresh the subnet information. This will
+            -- also result in creating an audit entry for this subnet.
+            UPDATE dhcp4_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = p_subnet_id;
+        ELSEIF scope_id = 4 THEN
+            -- If shared network specific option is added or modified,
+            -- update the modification timestamp of this shared network
+            -- to allow the servers to refresh the shared network
+            -- information. This will also result in creating an
+            -- audit entry for this shared network.
+           SELECT id INTO snid FROM dhcp4_shared_network WHERE name = network_name LIMIT 1;
+           UPDATE dhcp4_shared_network SET modification_ts = p_modification_ts
+                WHERE id = snid;
+        ELSEIF scope_id = 5 THEN
+            -- If pool specific option is added or modified, update
+            -- the modification timestamp of the owning subnet.
+            SELECT dhcp4_pool.subnet_id INTO sid FROM dhcp4_pool WHERE id = pool_id;
+            UPDATE dhcp4_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        END IF;
+    END IF;
+    RETURN;
+END;$$;
+
+-- Trigger function for dhcp4_options_AINS called AFTER INSERT on dhcp4_options
+CREATE OR REPLACE FUNCTION func_dhcp4_options_AINS() RETURNS TRIGGER AS $dhcp4_options_AINS$
+BEGIN
+    PERFORM createOptionAuditDHCP4('create', NEW.scope_id, NEW.option_id, NEW.dhcp4_subnet_id,
+                                   NEW.host_id, NEW.shared_network_name, NEW.pool_id,
+                                   NEW.modification_ts);
+    RETURN NULL;
+END;
+$dhcp4_options_AINS$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_options_AINS
+    AFTER INSERT ON dhcp4_options
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_options_AINS();
+
+-- Trigger function for dhcp4_options_AUPD called AFTER UPDATE on dhcp4_options
+CREATE OR REPLACE FUNCTION func_dhcp4_options_AUPD() RETURNS TRIGGER AS $dhcp4_options_AUPD$
+BEGIN
+    PERFORM createOptionAuditDHCP4('update', NEW.scope_id, NEW.option_id, NEW.dhcp4_subnet_id,
+                                   NEW.host_id, NEW.shared_network_name, NEW.pool_id,
+                                   NEW.modification_ts);
+    RETURN NULL;
+END;
+$dhcp4_options_AUPD$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_options_AUPD
+    AFTER UPDATE ON dhcp4_options
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_options_AUPD();
+
+-- Trigger function for dhcp4_options_ADEL called AFTER DELETE on dhcp4_options
+CREATE OR REPLACE FUNCTION func_dhcp4_options_ADEL() RETURNS TRIGGER AS $dhcp4_options_ADEL$
+BEGIN
+    PERFORM createOptionAuditDHCP4('delete', OLD.scope_id, OLD.option_id, OLD.dhcp4_subnet_id,
+                                   OLD.host_id, OLD.shared_network_name, OLD.pool_id,
+                                   NOW());
+    RETURN NULL;
+END;
+$dhcp4_options_ADEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_options_ADEL
+    AFTER DELETE ON dhcp4_options
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_options_ADEL();
+
+-- Trigger function for dhcp6_global_parameter_AINS called AFTER INSERT on dhcp6_global_parameter
+CREATE OR REPLACE FUNCTION func_dhcp6_global_parameter_AINS() RETURNS TRIGGER AS $dhcp6_global_parameter_AINS$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_global_parameter', NEW.id, 'create');
+    RETURN NULL;
+END;
+$dhcp6_global_parameter_AINS$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_global_parameter_AINS
+    AFTER INSERT ON dhcp6_global_parameter
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_global_parameter_AINS();
+
+-- Trigger function for dhcp6_global_parameter_AUPD called AFTER UPDATE on dhcp6_global_parameter
+CREATE OR REPLACE FUNCTION func_dhcp6_global_parameter_AUPD() RETURNS TRIGGER AS $dhcp6_global_parameter_AUPD$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_global_parameter', NEW.id, 'update');
+    RETURN NULL;
+END;
+$dhcp6_global_parameter_AUPD$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_global_parameter_AUPD
+    AFTER UPDATE ON dhcp6_global_parameter
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_global_parameter_AUPD();
+
+-- Trigger function for dhcp6_global_parameter_ADEL called AFTER DELETE on dhcp6_global_parameter
+CREATE OR REPLACE FUNCTION func_dhcp6_global_parameter_ADEL() RETURNS TRIGGER AS $dhcp6_global_parameter_ADEL$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_global_parameter', OLD.id, 'delete');
+    RETURN NULL;
+END;
+$dhcp6_global_parameter_ADEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_global_parameter_ADEL
+    AFTER DELETE ON dhcp6_global_parameter
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_global_parameter_ADEL();
+
+-- Trigger function for dhcp6_subnet_AINS called AFTER INSERT on dhcp6_subnet
+CREATE OR REPLACE FUNCTION func_dhcp6_subnet_AINS() RETURNS TRIGGER AS $dhcp6_subnet_AINS$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_subnet', NEW.subnet_id, 'create');
+    RETURN NULL;
+END;
+$dhcp6_subnet_AINS$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_subnet_AINS
+    AFTER INSERT ON dhcp6_subnet
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_subnet_AINS();
+
+-- Trigger function for dhcp6_subnet_AUPD called AFTER UPDATE on dhcp6_subnet
+CREATE OR REPLACE FUNCTION func_dhcp6_subnet_AUPD() RETURNS TRIGGER AS $dhcp6_subnet_AUPD$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_subnet', NEW.subnet_id, 'update');
+    RETURN NULL;
+END;
+$dhcp6_subnet_AUPD$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_subnet_AUPD
+    AFTER UPDATE ON dhcp6_subnet
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_subnet_AUPD();
+
+-- Trigger function for dhcp6_shared_network_AINS called AFTER INSERT on dhcp6_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp6_shared_network_AINS() RETURNS TRIGGER AS $dhcp6_shared_network_AINS$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_shared_network', NEW.id, 'create');
+    RETURN NULL;
+END;
+$dhcp6_shared_network_AINS$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_shared_network_AINS
+    AFTER INSERT ON dhcp6_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_shared_network_AINS();
+
+-- Trigger function for dhcp6_shared_network_AUPD called AFTER UPDATE on dhcp6_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp6_shared_network_AUPD() RETURNS TRIGGER AS $dhcp6_shared_network_AUPD$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_shared_network', NEW.id, 'update');
+    RETURN NULL;
+END;
+$dhcp6_shared_network_AUPD$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_shared_network_AUPD
+    AFTER UPDATE ON dhcp6_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_shared_network_AUPD();
+
+-- Trigger function for dhcp6_shared_network_ADEL called AFTER DELETE on dhcp6_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp6_shared_network_ADEL() RETURNS TRIGGER AS $dhcp6_shared_network_ADEL$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_shared_network', OLD.id, 'delete');
+    RETURN NULL;
+END;
+$dhcp6_shared_network_ADEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_shared_network_ADEL
+    AFTER DELETE ON dhcp6_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_shared_network_ADEL();
+
+-- Trigger function for dhcp6_option_def_AINS called AFTER INSERT on dhcp6_option_def
+CREATE OR REPLACE FUNCTION func_dhcp6_option_def_AINS() RETURNS TRIGGER AS $dhcp6_option_def_AINS$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_option_def', NEW.id, 'create');
+    RETURN NULL;
+END;
+$dhcp6_option_def_AINS$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_option_def_AINS
+    AFTER INSERT ON dhcp6_option_def
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_option_def_AINS();
+
+-- Trigger function for dhcp6_option_def_AUPD called AFTER UPDATE on dhcp6_option_def
+CREATE OR REPLACE FUNCTION func_dhcp6_option_def_AUPD() RETURNS TRIGGER AS $dhcp6_option_def_AUPD$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_option_def', NEW.id, 'update');
+    RETURN NULL;
+END;
+$dhcp6_option_def_AUPD$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_option_def_AUPD
+    AFTER UPDATE ON dhcp6_option_def
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_option_def_AUPD();
+
+-- Trigger function for dhcp6_option_def_ADEL called AFTER DELETE on dhcp6_option_def
+CREATE OR REPLACE FUNCTION func_dhcp6_option_def_ADEL() RETURNS TRIGGER AS $dhcp6_option_def_ADEL$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_option_def', OLD.id, 'delete');
+    RETURN NULL;
+END;
+$dhcp6_option_def_ADEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_option_def_ADEL
+    AFTER DELETE ON dhcp6_option_def
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_option_def_ADEL();
+
+-- - pool_id: identifier of the pool if the option
+--   belongs to the pool.
+-- - pd_pool_id: identifier of the pool if the option
+--   belongs to the pd pool.
+-- - modification_ts: modification timestamp of the
+--   option.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createOptionAuditDHCP6(modification_type VARCHAR(32),
+                                                  scope_id SMALLINT,
+                                                  option_id INT,
+                                                  subnet_id BIGINT,
+                                                  host_id INT,
+                                                  network_name VARCHAR(128),
+                                                  pool_id BIGINT,
+                                                  pd_pool_id BIGINT,
+                                                  modification_ts TIMESTAMP WITH TIME ZONE)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    -- These variables will hold shared network id and subnet id that
+    -- we will select.
+    snid VARCHAR(128);
+    sid BIGINT;
+    cascade_transaction BOOLEAN := false;
+
+BEGIN
+    -- Cascade transaction flag is set to true to prevent creation of
+    -- the audit entries for the options when the options are
+    -- created as part of the parent object creation or update.
+    -- For example: when the option is added as part of the subnet
+    -- addition, the cascade transaction flag is equal to true. If
+    -- the option is added into the existing subnet the cascade
+    -- transaction is equal to false. Note that depending on the option
+    -- scope the audit entry will contain the object_type value
+    -- of the parent object to cause the server to replace the
+    -- entire subnet. The only case when the object_type will be
+    -- set to 'dhcp6_options' is when a global option is added.
+    -- Global options do not have the owner.
+    cascade_transaction := get_session_boolean('kea.cascade_transaction');
+    IF cascade_transaction = false THEN
+        -- todo: host manager hasn't been updated to use audit
+        -- mechanisms so ignore host specific options for now.
+        IF scope_id = 0 THEN
+            -- If a global option is added or modified, create audit
+            -- entry for the 'dhcp6_options' table.
+            PERFORM createAuditEntryDHCP6('dhcp6_options', option_id, modification_type);
+        ELSEIF scope_id = 1 THEN
+            -- If subnet specific option is added or modified, create
+            -- audit entry for the entire subnet, which indicates that
+            -- it should be treated as the subnet update.
+            PERFORM createAuditEntryDHCP6('dhcp6_subnet', subnet_id, 'update');
+        ELSEIF scope_id = 4 THEN
+            -- If shared network specific option is added or modified,
+            -- create audit entry for the shared network which
+            -- indicates that it should be treated as the shared
+            -- network update.
+           SELECT id INTO snid FROM dhcp6_shared_network
+                WHERE name = network_name LIMIT 1;
+           PERFORM createAuditEntryDHCP6('dhcp6_shared_network', snid, 'update');
+        ELSEIF scope_id = 5 THEN
+            -- If pool specific option is added or modified, create
+            -- audit entry for the subnet which this pool belongs to.
+            SELECT dhcp6_pool.subnet_id INTO sid FROM dhcp6_pool WHERE id = pool_id;
+            PERFORM createAuditEntryDHCP6('dhcp6_subnet', sid, 'update');
+        ELSEIF scope_id = 6 THEN
+            -- If pd pool specific option is added or modified, create
+            -- audit entry for the subnet which this pd pool belongs to.
+            SELECT dhcp6_pd_pool.subnet_id INTO sid FROM dhcp6_pd_pool
+                WHERE id = pd_pool_id;
+            PERFORM createAuditEntryDHCP6('dhcp6_subnet', sid, 'update');
+        END IF;
+    END IF;
+    RETURN;
+END;$$;
+
+-- Trigger function for dhcp6_options_AINS called AFTER INSERT on dhcp6_options
+CREATE OR REPLACE FUNCTION func_dhcp6_options_AINS() RETURNS TRIGGER AS $dhcp6_options_AINS$
+BEGIN
+    PERFORM createOptionAuditDHCP6('create', NEW.scope_id, NEW.option_id, NEW.dhcp6_subnet_id,
+                                   NEW.host_id, NEW.shared_network_name, NEW.pool_id,
+                                   NEW.pd_pool_id, NEW.modification_ts);
+    RETURN NULL;
+END;
+$dhcp6_options_AINS$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_options_AINS
+    AFTER INSERT ON dhcp6_options
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_options_AINS();
+
+-- Trigger function for dhcp6_options_AUPD called AFTER UPDATE on dhcp6_options
+CREATE OR REPLACE FUNCTION func_dhcp6_options_AUPD() RETURNS TRIGGER AS $dhcp6_options_AUPD$
+BEGIN
+    PERFORM createOptionAuditDHCP6('update', NEW.scope_id, NEW.option_id, NEW.dhcp6_subnet_id,
+                                   NEW.host_id, NEW.shared_network_name, NEW.pool_id,
+                                   NEW.pd_pool_id, NEW.modification_ts);
+    RETURN NULL;
+END;
+$dhcp6_options_AUPD$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_options_AUPD
+    AFTER UPDATE ON dhcp6_options
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_options_AUPD();
+
+-- Trigger function for dhcp6_options_ADEL called AFTER DELETE on dhcp6_options
+CREATE OR REPLACE FUNCTION func_dhcp6_options_ADEL() RETURNS TRIGGER AS $dhcp6_options_ADEL$
+BEGIN
+    PERFORM createOptionAuditDHCP6('delete', OLD.scope_id, OLD.option_id, OLD.dhcp6_subnet_id,
+                                   OLD.host_id, OLD.shared_network_name, OLD.pool_id,
+                                   OLD.pd_pool_id, NOW());
+    RETURN NULL;
+END;
+$dhcp6_options_ADEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_options_ADEL
+    AFTER DELETE ON dhcp6_options
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_options_ADEL();
+
+-- Trigger function for dhcp4_server_AINS called AFTER INSERT on dhcp4_server
+CREATE OR REPLACE FUNCTION func_dhcp4_server_AINS() RETURNS TRIGGER AS $dhcp4_server_AINS$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_server', NEW.id, 'create');
+    RETURN NULL;
+END;
+$dhcp4_server_AINS$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_server_AINS
+    AFTER INSERT ON dhcp4_server
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_server_AINS();
+
+-- Trigger function for dhcp4_server_AUPD called AFTER UPDATE on dhcp4_server
+CREATE OR REPLACE FUNCTION func_dhcp4_server_AUPD() RETURNS TRIGGER AS $dhcp4_server_AUPD$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_server', NEW.id, 'update');
+    RETURN NULL;
+END;
+$dhcp4_server_AUPD$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_server_AUPD
+    AFTER UPDATE ON dhcp4_server
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_server_AUPD();
+
+-- Trigger function for dhcp4_server_ADEL called AFTER DELETE on dhcp4_server
+CREATE OR REPLACE FUNCTION func_dhcp4_server_ADEL() RETURNS TRIGGER AS $dhcp4_server_ADEL$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_server', OLD.id, 'delete');
+    RETURN NULL;
+END;
+$dhcp4_server_ADEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_server_ADEL
+    AFTER DELETE ON dhcp4_server
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_server_ADEL();
+
+-- Trigger function for dhcp6_server_AINS called AFTER INSERT on dhcp6_server
+CREATE OR REPLACE FUNCTION func_dhcp6_server_AINS() RETURNS TRIGGER AS $dhcp6_server_AINS$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_server', NEW.id, 'create');
+    RETURN NULL;
+END;
+$dhcp6_server_AINS$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_server_AINS
+    AFTER INSERT ON dhcp6_server
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_server_AINS();
+
+-- Trigger function for dhcp6_server_AUPD called AFTER UPDATE on dhcp6_server
+CREATE OR REPLACE FUNCTION func_dhcp6_server_AUPD() RETURNS TRIGGER AS $dhcp6_server_AUPD$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_server', NEW.id, 'update');
+    RETURN NULL;
+END;
+$dhcp6_server_AUPD$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_server_AUPD
+    AFTER UPDATE ON dhcp6_server
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_server_AUPD();
+
+-- Trigger function for dhcp6_server_ADEL called AFTER DELETE on dhcp6_server
+CREATE OR REPLACE FUNCTION func_dhcp6_server_ADEL() RETURNS TRIGGER AS $dhcp6_server_ADEL$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_server', OLD.id, 'delete');
+    RETURN NULL;
+END;
+$dhcp6_server_ADEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_server_ADEL
+    AFTER DELETE ON dhcp6_server
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_server_ADEL();
+
+-- Trigger function for dhcp4_shared_network_BDEL called BEFORE DELETE on dhcp4_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp4_shared_network_BDEL() RETURNS TRIGGER AS $dhcp4_shared_network_BDEL$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_shared_network', OLD.id, 'delete');
+    DELETE FROM dhcp4_options WHERE shared_network_name = OLD.name;
+    RETURN OLD;
+END;
+$dhcp4_shared_network_BDEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_shared_network_BDEL
+    BEFORE DELETE ON dhcp4_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_shared_network_BDEL();
+
+-- Trigger function for dhcp4_subnet_BDEL called BEFORE DELETE on dhcp4_subnet
+CREATE OR REPLACE FUNCTION func_dhcp4_subnet_BDEL() RETURNS TRIGGER AS $dhcp4_subnet_BDEL$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_subnet', OLD.subnet_id, 'delete');
+    DELETE FROM dhcp4_pool WHERE subnet_id = OLD.subnet_id;
+    DELETE FROM dhcp4_options WHERE dhcp4_subnet_id = OLD.subnet_id;
+    RETURN OLD;
+END;
+$dhcp4_subnet_BDEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_subnet_BDEL
+    BEFORE DELETE ON dhcp4_subnet
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_subnet_BDEL();
+
+-- Trigger function for dhcp6_shared_network_BDEL called BEFORE DELETE on dhcp6_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp6_shared_network_BDEL() RETURNS TRIGGER AS $dhcp6_shared_network_BDEL$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_shared_network', OLD.id, 'delete');
+    DELETE FROM dhcp6_options WHERE shared_network_name = OLD.name;
+    RETURN OLD;
+END;
+$dhcp6_shared_network_BDEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_shared_network_BDEL
+    BEFORE DELETE ON dhcp6_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_shared_network_BDEL();
+
+-- Trigger function for dhcp6_subnet_BDEL called BEFORE DELETE on dhcp6_subnet
+CREATE OR REPLACE FUNCTION func_dhcp6_subnet_BDEL() RETURNS TRIGGER AS $dhcp6_subnet_BDEL$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_subnet', OLD.subnet_id, 'delete');
+    DELETE FROM dhcp6_pool WHERE subnet_id = OLD.subnet_id;
+    DELETE FROM dhcp6_pd_pool WHERE subnet_id = OLD.subnet_id;
+    DELETE FROM dhcp6_options WHERE dhcp6_subnet_id = OLD.subnet_id;
+    RETURN OLD;
+END;
+$dhcp6_subnet_BDEL$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_subnet_BDEL
+    BEFORE DELETE ON dhcp6_subnet
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_subnet_BDEL();
+-- Trigger function for dhcp6_pd_pool_BDEL called BEFORE DELETE on dhcp6_pd_pool
+CREATE OR REPLACE FUNCTION func_dhcp6_pd_pool_BDEL() RETURNS TRIGGER AS $dhcp6_pd_pool_BDEL$
+BEGIN
+    DELETE FROM dhcp6_options WHERE scope_id = 6 AND pd_pool_id = OLD.id;
+    RETURN OLD;
+END;
+$dhcp6_pd_pool_BDEL$
+LANGUAGE plpgsql;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '7', minor = '0';
+
+-- This line concludes the schema upgrade to version 7.0.
+
+-- This line starts the schema upgrade to version 8.0.
+
+-- Add a few missing elements for CB and functions for kea-admin's lease-dump
+-- and lease-upload commands.
+
+-- -----------------------------------------------------------------------
+-- Extend the table holding DHCPv4 option definitions with a nullable
+-- column matching option defintions with client classes.
+-- -----------------------------------------------------------------------
+ALTER TABLE dhcp4_option_def
+    ADD COLUMN class_id BIGINT NULL DEFAULT NULL;
+
+ALTER TABLE dhcp4_option_def
+  ADD CONSTRAINT fk_dhcp4_option_def_client_class_id
+    FOREIGN KEY (class_id)
+    REFERENCES dhcp4_client_class (id)
+    ON DELETE CASCADE
+    ON UPDATE CASCADE;
+
+-- -----------------------------------------------------------------------
+-- Extend the table holding DHCPv6 option definitions with a nullable
+-- column matching option defintions with client classes.
+-- -----------------------------------------------------------------------
+ALTER TABLE dhcp6_option_def
+    ADD COLUMN class_id BIGINT NULL DEFAULT NULL;
+
+ALTER TABLE dhcp6_option_def
+  ADD CONSTRAINT fk_dhcp6_option_def_client_class_id
+    FOREIGN KEY (class_id)
+    REFERENCES dhcp6_client_class (id)
+    ON DELETE CASCADE
+    ON UPDATE CASCADE;
+
+-- -----------------------------------------------------------------------
+-- Add missing preferred_lifetime columns to dhcp6_client_class table.
+-- -----------------------------------------------------------------------
+ALTER TABLE dhcp6_client_class
+    ADD COLUMN preferred_lifetime BIGINT DEFAULT NULL,
+    ADD COLUMN min_preferred_lifetime BIGINT DEFAULT NULL,
+    ADD COLUMN max_preferred_lifetime BIGINT DEFAULT NULL;
+
+-- -----------------------------------------------------------------------
+-- Add option scopes
+-- -----------------------------------------------------------------------
+-- Add scope for shared network specific options.
+INSERT INTO dhcp_option_scope (scope_id, scope_name)
+    VALUES(4, 'shared-network');
+
+-- Add scope for pool specific options.
+INSERT INTO dhcp_option_scope (scope_id, scope_name)
+    VALUES(5, 'pool');
+
+-- Add scope for PD pool specific options.
+INSERT INTO dhcp_option_scope (scope_id, scope_name)
+    VALUES(6, 'pd-pool');
+
+-- Drop the existing function, createOptionAuditDHCP6 so we can replace it
+-- with one that has slightly different arguments.
+DROP FUNCTION IF EXISTS createOptionAuditDHCP6(modification_type VARCHAR(32),
+                                               scope_id SMALLINT, option_id INT, subnet_id BIGINT,
+                                               host_id INT, network_name VARCHAR(128),
+                                               pool_id BIGINT, pd_pool_id BIGINT,
+                                               modification_ts TIMESTAMP WITH TIME ZONE);
+
+-- -----------------------------------------------------
+--
+-- New version of the createOptionAuditDHCP6 stored
+-- procedure which updates modification timestamp of
+-- a parent object when an option is modified.
+--
+-- The following parameters are passed to the procedure:
+-- - modification_type: "create", "update" or "delete"
+-- - scope_id: identifier of the option scope, e.g.
+--   global, subnet specific etc. See dhcp_option_scope
+--   for specific values.
+-- - option_id: identifier of the option.
+-- - subnet_id: identifier of the subnet if the option
+--   belongs to the subnet.
+-- - host_id: identifier of the host if the option
+-- - belongs to the host.
+-- - network_name: shared network name if the option
+--   belongs to the shared network.
+-- - pool_id: identifier of the pool if the option
+--   belongs to the pool.
+-- - pd_pool_id: identifier of the pool if the option
+--   belongs to the pd pool.
+-- - modification_ts: modification timestamp of the
+--   option.
+--   Some arguments are prefixed with "p_" to avoid ambiguity
+--   with column names in SQL statements. PostgreSQL does not
+--   allow table aliases to be used with column names in update
+--   set expressions.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createOptionAuditDHCP6(modification_type VARCHAR(32),
+                                                  scope_id SMALLINT,
+                                                  option_id INT,
+                                                  p_subnet_id BIGINT,
+                                                  host_id INT,
+                                                  network_name VARCHAR(128),
+                                                  pool_id BIGINT,
+                                                  pd_pool_id BIGINT,
+                                                  p_modification_ts TIMESTAMP WITH TIME ZONE)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    -- These variables will hold shared network id and subnet id that
+    -- we will select.
+    snid VARCHAR(128);
+    sid BIGINT;
+    cascade_transaction BOOLEAN := false;
+
+BEGIN
+    -- Cascade transaction flag is set to true to prevent creation of
+    -- the audit entries for the options when the options are
+    -- created as part of the parent object creation or update.
+    -- For example: when the option is added as part of the subnet
+    -- addition, the cascade transaction flag is equal to true. If
+    -- the option is added into the existing subnet the cascade
+    -- transaction is equal to false. Note that depending on the option
+    -- scope the audit entry will contain the object_type value
+    -- of the parent object to cause the server to replace the
+    -- entire subnet. The only case when the object_type will be
+    -- set to 'dhcp6_options' is when a global option is added.
+    -- Global options do not have the owner.
+    cascade_transaction := get_session_boolean('kea.cascade_transaction');
+    IF cascade_transaction = false THEN
+        -- todo: host manager hasn't been updated to use audit
+        -- mechanisms so ignore host specific options for now.
+        IF scope_id = 0 THEN
+            -- If a global option is added or modified, create audit
+            -- entry for the 'dhcp6_options' table.
+            PERFORM createAuditEntryDHCP6('dhcp6_options', option_id, modification_type);
+        ELSEIF scope_id = 1 THEN
+            -- If subnet specific option is added or modified, update
+            -- the modification timestamp of this subnet to allow the
+            -- servers to refresh the subnet information. This will
+            -- also result in creating an audit entry for this subnet.
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = p_subnet_id;
+        ELSEIF scope_id = 4 THEN
+            -- If shared network specific option is added or modified,
+            -- update the modification timestamp of this shared network
+            -- to allow the servers to refresh the shared network
+            -- information. This will also result in creating an
+            -- audit entry for this shared network.
+           SELECT id INTO snid FROM dhcp6_shared_network WHERE name = network_name LIMIT 1;
+           UPDATE dhcp6_shared_network SET modification_ts = p_modification_ts
+                WHERE id = snid;
+        ELSEIF scope_id = 5 THEN
+            -- If pool specific option is added or modified, update
+            -- the modification timestamp of the owning subnet.
+            SELECT dhcp6_pool.subnet_id INTO sid FROM dhcp6_pool WHERE id = pool_id;
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        ELSEIF scope_id = 6 THEN
+            -- If pd pool specific option is added or modified, create
+            -- audit entry for the subnet which this pool belongs to.
+            SELECT dhcp6_pd_pool.subnet_id INTO sid FROM dhcp6_pd_pool WHERE id = pool_id;
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        END IF;
+    END IF;
+    RETURN;
+END;$$;
+
+-- Fix mangled constraints on dhcp4_subnet_server table.
+ALTER TABLE dhcp4_subnet_server
+    DROP CONSTRAINT fk_dhcp6_subnet_server_server_id,
+    ADD CONSTRAINT fk_dhcp4_subnet_server_server_id
+        FOREIGN KEY (server_id) REFERENCES dhcp4_server (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+    DROP CONSTRAINT fk_dhcp6_subnet_server_subnet_id,
+    ADD CONSTRAINT fk_dhcp4_subnet_server_subnet_id
+        FOREIGN KEY (subnet_id) REFERENCES dhcp4_subnet (subnet_id) ON DELETE CASCADE ON UPDATE NO ACTION;
+
+-- Add missing foreign key indexes. PostgreSQL does not automatically create indexes for
+-- foreign key constraints. These have been added using the basic guideline:
+--
+-- If the constraint does not reference a static table (e.g. parameter_data_type),
+-- and the referencing column is not the primary key or the first
+-- column in the primary key, and does not already have an index, then an index
+-- should be added to the table for the referencing column.
+--
+-- dhcp6_global_parameter_server
+CREATE INDEX  fk_dhcp6_global_parameter_server_server_id ON dhcp6_global_parameter_server (server_id);
+
+-- dhcp6_options
+-- Missing foreign key constraint and indexes
+ALTER TABLE dhcp6_options ADD CONSTRAINT fk_dhcp6_options_subnet
+    FOREIGN KEY (dhcp6_subnet_id)
+        REFERENCES dhcp6_subnet(subnet_id)
+        ON DELETE CASCADE ON UPDATE CASCADE;
+
+CREATE INDEX fk_dhcp6_options_subnet ON dhcp6_options (dhcp6_subnet_id);
+CREATE INDEX fk_dhcp6_options_pd_pool ON dhcp6_options (pd_pool_id);
+CREATE INDEX fk_dhcp6_options_pool ON dhcp6_options (pool_id);
+CREATE INDEX fk_dhcp6_options_shared_network ON dhcp6_options (shared_network_name);
+
+-- dhcp6_option_def_server
+-- Missing foreign key constraints and index
+ALTER TABLE dhcp6_option_def_server
+    ADD CONSTRAINT fk_dhcp6_option_def_server_option_def_id FOREIGN KEY (option_def_id)
+        REFERENCES dhcp6_option_def (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+    ADD CONSTRAINT fk_dhcp6_option_def_server_server_id FOREIGN KEY (server_id)
+        REFERENCES dhcp6_server (id) ON DELETE NO ACTION ON UPDATE NO ACTION;
+
+CREATE INDEX fk_dhcp6_option_def_server_server_id ON dhcp6_option_def_server (server_id);
+
+-- dhcp6_option_def
+CREATE INDEX fk_dhcp6_option_def_client_class_id ON dhcp6_option_def (class_id);
+
+-- dhcp4_global_parameter_server
+CREATE INDEX  fk_dhcp4_global_parameter_server_server_id ON dhcp4_global_parameter_server (server_id);
+
+-- dhcp4_options
+-- Missing foreign key constraint and indexes
+ALTER TABLE dhcp4_options ADD CONSTRAINT fk_dhcp4_options_subnet
+    FOREIGN KEY (dhcp4_subnet_id)
+        REFERENCES dhcp4_subnet(subnet_id)
+        ON DELETE CASCADE ON UPDATE CASCADE;
+
+CREATE INDEX fk_dhcp4_options_subnet ON dhcp4_options (dhcp4_subnet_id);
+CREATE INDEX fk_dhcp4_options_pool ON dhcp4_options (pool_id);
+CREATE INDEX fk_dhcp4_options_shared_network ON dhcp4_options (shared_network_name);
+
+-- dhcp4_option_def_server
+-- Missing foreign key constraints and index
+ALTER TABLE dhcp4_option_def_server
+    ADD CONSTRAINT fk_dhcp4_option_def_server_option_def_id FOREIGN KEY (option_def_id)
+        REFERENCES dhcp4_option_def (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+    ADD CONSTRAINT fk_dhcp4_option_def_server_server_id FOREIGN KEY (server_id)
+        REFERENCES dhcp4_server (id) ON DELETE NO ACTION ON UPDATE NO ACTION;
+
+CREATE INDEX fk_dhcp4_option_def_server_server_id ON dhcp4_option_def_server (server_id);
+
+-- dhcp4_option_def
+CREATE INDEX fk_dhcp4_option_def_client_class_id ON dhcp4_option_def (class_id);
+
+-- Create a function that separates groups of two hexadecimals
+-- with colons.
+CREATE OR REPLACE FUNCTION colonSeparatedHex(hex TEXT)
+RETURNS TEXT
+AS $$
+DECLARE
+    i INT := 3;
+    length INT := LENGTH(hex);
+    output TEXT;
+BEGIN
+    -- Add a leading zero if the first octet has a single hexadecimal character.
+    IF MOD(length, 2) = 1 THEN
+        hex := CONCAT('0', hex);
+        length := length + 1;
+    END IF;
+
+    -- Start with the first octet.
+    output := SUBSTR(hex, 1, 2);
+
+    -- Add one octet at a time and a leading colon with each.
+    WHILE i < length LOOP
+        output := CONCAT(output, ':', SUBSTR(hex, i, 2));
+        i := i + 2;
+    END LOOP;
+
+    -- Memfile uses lowercase hexadecimals.
+    output := LOWER(output);
+
+    RETURN output;
+END
+$$ LANGUAGE plpgsql;
+
+-- Modify the function to output a memfile-ready CSV file.
+-- Some columns that are SMALLINT in the lease4 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+DROP FUNCTION IF EXISTS lease4DumpData();
+CREATE OR REPLACE FUNCTION lease4DumpData()
+RETURNS TABLE (
+    address INET,
+    hwaddr VARCHAR,
+    client_id VARCHAR,
+    valid_lifetime BIGINT,
+    expire BIGINT,
+    subnet_id BIGINT,
+    fqdn_fwd INT,
+    fqdn_rev INT,
+    hostname VARCHAR,
+    state INT8,
+    user_context VARCHAR
+) AS $$
+    SELECT
+        ('0.0.0.0'::inet + address),
+        colonSeparatedHex(encode(hwaddr, 'hex')),
+        colonSeparatedHex(encode(client_id, 'hex')),
+        valid_lifetime,
+        extract(epoch from expire)::bigint,
+        subnet_id,
+        fqdn_fwd::int,
+        fqdn_rev::int,
+        replace(hostname, ',', '&#x2c'),
+        state,
+        replace(user_context, ',', '&#x2c')
+    FROM lease4
+    ORDER BY address;
+$$ LANGUAGE SQL;
+
+-- hwtype and hwaddr_source need to be last to match memfile format.
+DROP FUNCTION IF EXISTS lease6DumpHeader();
+CREATE OR REPLACE FUNCTION lease6DumpHeader()
+RETURNS TEXT AS $$
+    SELECT CAST('address,duid,valid_lifetime,expire,subnet_id,pref_lifetime,lease_type,iaid,prefix_len,fqdn_fwd,fqdn_rev,hostname,hwaddr,state,user_context,hwtype,hwaddr_source' AS TEXT) AS result;
+$$ LANGUAGE SQL;
+
+-- Modify the function to output a memfile-ready CSV file.
+-- Some columns that are SMALLINT in the lease6 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+DROP FUNCTION IF EXISTS lease6DumpData();
+CREATE OR REPLACE FUNCTION lease6DumpData()
+RETURNS TABLE (
+    address VARCHAR,
+    duid VARCHAR,
+    valid_lifetime BIGINT,
+    expire BIGINT,
+    subnet_id BIGINT,
+    pref_lifetime BIGINT,
+    lease_type SMALLINT,
+    iaid INT,
+    prefix_len SMALLINT,
+    fqdn_fwd INT,
+    fqdn_rev INT,
+    hostname VARCHAR,
+    hwaddr VARCHAR,
+    state INT8,
+    user_context VARCHAR,
+    hwtype SMALLINT,
+    hwaddr_source SMALLINT
+) AS $$
+    SELECT
+        address,
+        colonSeparatedHex(encode(duid, 'hex')),
+        valid_lifetime,
+        extract(epoch from expire)::bigint,
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd::int,
+        fqdn_rev::int,
+        replace(hostname, ',', '&#x2c'),
+        colonSeparatedHex(encode(hwaddr, 'hex')),
+        state,
+        replace(user_context, ',', '&#x2c'),
+        hwtype,
+        hwaddr_source
+    FROM lease6
+    ORDER BY address;
+$$ LANGUAGE SQL;
+
+-- Create a procedure that inserts a v4 lease from memfile data.
+-- Some columns that are SMALLINT in the lease4 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+CREATE OR REPLACE FUNCTION lease4Upload(
+    IN address VARCHAR,
+    IN hwaddr VARCHAR,
+    IN client_id VARCHAR,
+    IN valid_lifetime BIGINT,
+    IN expire BIGINT,
+    IN subnet_id BIGINT,
+    IN fqdn_fwd INT,
+    IN fqdn_rev INT,
+    IN hostname VARCHAR,
+    IN state INT8,
+    IN user_context VARCHAR
+) RETURNS VOID AS $$
+BEGIN
+    INSERT INTO lease4 (
+        address,
+        hwaddr,
+        client_id,
+        valid_lifetime,
+        expire,
+        subnet_id,
+        fqdn_fwd,
+        fqdn_rev,
+        hostname,
+        state,
+        user_context
+    ) VALUES (
+        address::inet - '0.0.0.0'::inet,
+        decode(replace(hwaddr, ':', ''), 'hex'),
+        decode(replace(client_id, ':', ''), 'hex'),
+        valid_lifetime,
+        to_timestamp(expire),
+        subnet_id,
+        fqdn_fwd::int::boolean,
+        fqdn_rev::int::boolean,
+        replace(hostname, '&#x2c', ','),
+        state,
+        replace(user_context, '&#x2c', ',')
+    );
+END
+$$ LANGUAGE plpgsql;
+
+-- Create a procedure that inserts a v6 lease from memfile data.
+-- Some columns that are SMALLINT in the lease6 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+CREATE OR REPLACE FUNCTION lease6Upload(
+    IN address VARCHAR,
+    IN duid VARCHAR,
+    IN valid_lifetime BIGINT,
+    IN expire BIGINT,
+    IN subnet_id BIGINT,
+    IN pref_lifetime BIGINT,
+    IN lease_type INT,
+    IN iaid INT,
+    IN prefix_len INT,
+    IN fqdn_fwd INT,
+    IN fqdn_rev INT,
+    IN hostname VARCHAR,
+    IN hwaddr VARCHAR,
+    IN state INT8,
+    IN user_context VARCHAR,
+    IN hwtype INT,
+    IN hwaddr_source INT
+) RETURNS VOID AS $$
+BEGIN
+    INSERT INTO lease6 (
+        address,
+        duid,
+        valid_lifetime,
+        expire,
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd,
+        fqdn_rev,
+        hostname,
+        hwaddr,
+        state,
+        user_context,
+        hwtype,
+        hwaddr_source
+    ) VALUES (
+        address,
+        decode(replace(duid, ':', ''), 'hex'),
+        valid_lifetime,
+        to_timestamp(expire),
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd::int::boolean,
+        fqdn_rev::int::boolean,
+        replace(hostname, '&#x2c', ','),
+        decode(replace(hwaddr, ':', ''), 'hex'),
+        state,
+        replace(user_context, '&#x2c', ','),
+        hwtype,
+        hwaddr_source
+    );
+END
+$$ LANGUAGE plpgsql;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '8', minor = '0';
+
+-- This line concludes the schema upgrade to version 8.0.
+
+-- This line starts the schema upgrade to version 9.0.
+
+-- Add missing cascade to constraint on dhcp4/6_subnet_server tables.
+ALTER TABLE dhcp4_subnet_server
+    DROP CONSTRAINT fk_dhcp4_subnet_server_server_id,
+    ADD CONSTRAINT fk_dhcp4_subnet_server_server_id
+        FOREIGN KEY (server_id) REFERENCES dhcp4_server (id) ON DELETE CASCADE ON UPDATE CASCADE,
+    DROP CONSTRAINT fk_dhcp4_subnet_server_subnet_id,
+    ADD CONSTRAINT fk_dhcp4_subnet_server_subnet_id
+        FOREIGN KEY (subnet_id) REFERENCES dhcp4_subnet (subnet_id) ON DELETE CASCADE ON UPDATE CASCADE;
+
+ALTER TABLE dhcp6_subnet_server
+    DROP CONSTRAINT fk_dhcp6_subnet_server_server_id,
+    ADD CONSTRAINT fk_dhcp6_subnet_server_server_id
+        FOREIGN KEY (server_id) REFERENCES dhcp6_server (id) ON DELETE CASCADE ON UPDATE CASCADE,
+    DROP CONSTRAINT fk_dhcp6_subnet_server_subnet_id,
+    ADD CONSTRAINT fk_dhcp6_subnet_server_subnet_id
+        FOREIGN KEY (subnet_id) REFERENCES dhcp6_subnet (subnet_id) ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- Fix constraint typo on dhcp4_option_def_server
+ALTER TABLE dhcp4_option_def_server
+    DROP CONSTRAINT dhcp4_option_def_server_option_def_id_fkey,
+    ADD CONSTRAINT dhcp4_option_def_server_option_def_id_fkey
+        FOREIGN KEY (option_def_id) REFERENCES dhcp4_option_def(id) ON DELETE CASCADE;
+
+-- DROP shared-network ADEL triggers that should not exist.
+DROP TRIGGER IF EXISTS dhcp4_shared_network_ADEL on dhcp4_shared_network CASCADE;
+DROP TRIGGER IF EXISTS dhcp6_shared_network_ADEL on dhcp6_shared_network CASCADE;
+
+-- Replace createOptionAuditDHCP4() with a version that has local variable
+-- snid correctly declared as a BIGINT.
+--
+-- -----------------------------------------------------
+--
+-- Stored procedure which updates modification timestamp of
+-- a parent object when an option is modified.
+--
+-- The following parameters are passed to the procedure:
+-- - modification_type: "create", "update" or "delete"
+-- - scope_id: identifier of the option scope, e.g.
+--   global, subnet specific etc. See dhcp_option_scope
+--   for specific values.
+-- - option_id: identifier of the option.
+-- - p_subnet_id: identifier of the subnet if the option
+--   belongs to the subnet.
+-- - host_id: identifier of the host if the option
+-- - belongs to the host.
+-- - network_name: shared network name if the option
+--   belongs to the shared network.
+-- - pool_id: identifier of the pool if the option
+--   belongs to the pool.
+-- - p_modification_ts: modification timestamp of the
+--   option.
+--   Some arguments are prefixed with "p_" to avoid ambiguity
+--   with column names in SQL statements. PostgreSQL does not
+--   allow table aliases to be used with column names in update
+--   set expressions.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createOptionAuditDHCP4(modification_type VARCHAR,
+                                                  scope_id SMALLINT,
+                                                  option_id INT,
+                                                  p_subnet_id BIGINT,
+                                                  host_id INT,
+                                                  network_name VARCHAR,
+                                                  pool_id BIGINT,
+                                                  p_modification_ts TIMESTAMP WITH TIME ZONE)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    -- These variables will hold shared network id and subnet id that
+    -- we will select.
+    snid BIGINT;
+    sid BIGINT;
+    cascade_transaction BOOLEAN;
+BEGIN
+    -- Cascade transaction flag is set to true to prevent creation of
+    -- the audit entries for the options when the options are
+    -- created as part of the parent object creation or update.
+    -- For example: when the option is added as part of the subnet
+    -- addition, the cascade transaction flag is equal to true. If
+    -- the option is added into the existing subnet the cascade
+    -- transaction is equal to false. Note that depending on the option
+    -- scope the audit entry will contain the object_type value
+    -- of the parent object to cause the server to replace the
+    -- entire subnet. The only case when the object_type will be
+    -- set to 'dhcp4_options' is when a global option is added.
+    -- Global options do not have the owner.
+
+    cascade_transaction := get_session_boolean('kea.cascade_transaction');
+    IF cascade_transaction = false THEN
+        -- todo: host manager hasn't been updated to use audit
+        -- mechanisms so ignore host specific options for now.
+        IF scope_id = 0 THEN
+            -- If a global option is added or modified, create audit
+            -- entry for the 'dhcp4_options' table.
+            PERFORM createAuditEntryDHCP4('dhcp4_options', option_id, modification_type);
+        ELSEIF scope_id = 1 THEN
+            -- If subnet specific option is added or modified, update
+            -- the modification timestamp of this subnet to allow the
+            -- servers to refresh the subnet information. This will
+            -- also result in creating an audit entry for this subnet.
+            UPDATE dhcp4_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = p_subnet_id;
+        ELSEIF scope_id = 4 THEN
+            -- If shared network specific option is added or modified,
+            -- update the modification timestamp of this shared network
+            -- to allow the servers to refresh the shared network
+            -- information. This will also result in creating an
+            -- audit entry for this shared network.
+           SELECT id INTO snid FROM dhcp4_shared_network WHERE name = network_name LIMIT 1;
+           UPDATE dhcp4_shared_network SET modification_ts = p_modification_ts
+                WHERE id = snid;
+        ELSEIF scope_id = 5 THEN
+            -- If pool specific option is added or modified, update
+            -- the modification timestamp of the owning subnet.
+            SELECT dhcp4_pool.subnet_id INTO sid FROM dhcp4_pool WHERE id = pool_id;
+            UPDATE dhcp4_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        END IF;
+    END IF;
+    RETURN;
+END;$$;
+
+-- Replace createOptionAuditDHCP6() with a version that has local variable
+-- snid correctly declared as a BIGINT.
+--
+-- -----------------------------------------------------
+--
+-- Stored procedure which updates modification timestamp of
+-- a parent object when an option is modified.
+--
+-- The following parameters are passed to the procedure:
+-- - modification_type: "create", "update" or "delete"
+-- - scope_id: identifier of the option scope, e.g.
+--   global, subnet specific etc. See dhcp_option_scope
+--   for specific values.
+-- - option_id: identifier of the option.
+-- - p_subnet_id: identifier of the subnet if the option
+--   belongs to the subnet.
+-- - host_id: identifier of the host if the option
+-- - belongs to the host.
+-- - network_name: shared network name if the option
+--   belongs to the shared network.
+-- - pool_id: identifier of the pool if the option
+--   belongs to the pool.
+-- - pd_pool_id: identifier of the pool if the option
+--   belongs to the pd pool.
+-- - p_modification_ts: modification timestamp of the
+--   option.
+--   Some arguments are prefixed with "p_" to avoid ambiguity
+--   with column names in SQL statements. PostgreSQL does not
+--   allow table aliases to be used with column names in update
+--   set expressions.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createOptionAuditDHCP6(modification_type VARCHAR,
+                                                  scope_id SMALLINT,
+                                                  option_id INT,
+                                                  p_subnet_id BIGINT,
+                                                  host_id INT,
+                                                  network_name VARCHAR,
+                                                  pool_id BIGINT,
+                                                  pd_pool_id BIGINT,
+                                                  p_modification_ts TIMESTAMP WITH TIME ZONE)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    -- These variables will hold shared network id and subnet id that
+    -- we will select.
+    snid BIGINT;
+    sid BIGINT;
+    cascade_transaction BOOLEAN;
+BEGIN
+    -- Cascade transaction flag is set to true to prevent creation of
+    -- the audit entries for the options when the options are
+    -- created as part of the parent object creation or update.
+    -- For example: when the option is added as part of the subnet
+    -- addition, the cascade transaction flag is equal to true. If
+    -- the option is added into the existing subnet the cascade
+    -- transaction is equal to false. Note that depending on the option
+    -- scope the audit entry will contain the object_type value
+    -- of the parent object to cause the server to replace the
+    -- entire subnet. The only case when the object_type will be
+    -- set to 'dhcp6_options' is when a global option is added.
+    -- Global options do not have the owner.
+
+    cascade_transaction := get_session_boolean('kea.cascade_transaction');
+    IF cascade_transaction = false THEN
+        -- todo: host manager hasn't been updated to use audit
+        -- mechanisms so ignore host specific options for now.
+        IF scope_id = 0 THEN
+            -- If a global option is added or modified, create audit
+            -- entry for the 'dhcp6_options' table.
+            PERFORM createAuditEntryDHCP6('dhcp6_options', option_id, modification_type);
+        ELSEIF scope_id = 1 THEN
+            -- If subnet specific option is added or modified, update
+            -- the modification timestamp of this subnet to allow the
+            -- servers to refresh the subnet information. This will
+            -- also result in creating an audit entry for this subnet.
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = p_subnet_id;
+        ELSEIF scope_id = 4 THEN
+            -- If shared network specific option is added or modified,
+            -- update the modification timestamp of this shared network
+            -- to allow the servers to refresh the shared network
+            -- information. This will also result in creating an
+            -- audit entry for this shared network.
+           SELECT id INTO snid FROM dhcp6_shared_network WHERE name = network_name LIMIT 1;
+           UPDATE dhcp6_shared_network SET modification_ts = p_modification_ts
+                WHERE id = snid;
+        ELSEIF scope_id = 5 THEN
+            -- If pool specific option is added or modified, update
+            -- the modification timestamp of the owning subnet.
+            SELECT dhcp6_pool.subnet_id INTO sid FROM dhcp6_pool WHERE id = pool_id;
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        ELSEIF scope_id = 6 THEN
+            -- If pd pool specific option is added or modified, create
+            -- audit entry for the subnet which this pool belongs to.
+            SELECT dhcp6_pd_pool.subnet_id INTO sid FROM dhcp6_pd_pool WHERE id = pool_id;
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        END IF;
+    END IF;
+    RETURN;
+END;$$;
+
+-- Returns the epoch GMT time in second from a timestamp with time zone
+--
+-- param input_ts timestamp value to convert
+-- return a BIGINT containing the number of seconds since the epoch in GMT.
+CREATE OR REPLACE FUNCTION gmt_epoch(input_ts TIMESTAMP WITH TIME ZONE)
+RETURNS BIGINT
+AS $$
+DECLARE
+    gmt_epoch BIGINT;
+BEGIN
+    SELECT (extract(epoch from input_ts) + extract(timezone from input_ts))::BIGINT INTO gmt_epoch;
+    RETURN gmt_epoch;
+    EXCEPTION
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'gmt_epoch(%) : failed, sqlstate: %', input_ts, sqlstate;
+END;$$
+LANGUAGE plpgsql;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '9', minor = '0';
+
+-- This line concludes the schema upgrade to version 9.0.
+
+-- This line starts the schema upgrade to version 10.0.
+
+-- It adds corrections for client classes for CB
+
+-- Replace setClientClass4Order():
+-- 1. l_depend_on_known_indirectly needs to be BOOL
+-- 2. follow_class_index needs to be BIGINT
+
+-- -----------------------------------------------------------------------
+-- Stored procedure positioning an inserted or updated client class
+-- within the class hierarchy, depending on the value of the
+-- new_follow_class_name parameter.
+--
+-- Parameters:
+-- - id id of the positioned class,
+-- - new_follow_class_name name of the class after which this class should be
+--   positioned within the class hierarchy.
+-- - old_follow_class_name previous name of the class after which this
+--   class was positioned within the class hierarchy.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION setClientClass4Order(id BIGINT,
+                                                new_follow_class_name VARCHAR(128),
+                                                old_follow_class_name VARCHAR(128))
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    -- Used to fetch class's current value for depend_on_known_indirectly
+    l_depend_on_known_indirectly BOOL := false;
+
+    -- Optionally set if the follow_class_name column value is specified.
+    follow_class_index BIGINT;
+BEGIN
+    -- Fetch the class's current value of depend_on_known_indirectly.
+    SELECT depend_on_known_indirectly INTO l_depend_on_known_indirectly
+        FROM dhcp4_client_class_order WHERE id = class_id;
+
+    -- Save it to the current session for use elsewhere during this transaction.
+    -- Note this does not work prior to Postgres 9.2 unless the variables are
+    -- defined in postgresql.conf. I think for now we put up with CB not supported
+    -- prior to 9.2 or we tell people how to edit the conf file.
+    PERFORM set_session_value('kea.depend_on_known_indirectly', l_depend_on_known_indirectly);
+
+    -- Bail if the class is updated without re-positioning.
+    IF(
+       l_depend_on_known_indirectly IS NOT NULL AND
+       ((new_follow_class_name IS NULL AND old_follow_class_name IS NULL) OR
+        (new_follow_class_name = old_follow_class_name))
+    ) THEN
+        -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+        -- whenever the dhcp4_client_class record is updated. Such update may include
+        -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+        -- This value will be later adjusted when dependencies are inserted.
+        -- TKM should we update the session value also or is it moot?
+        UPDATE dhcp4_client_class_order SET depend_on_known_indirectly = false
+            WHERE class_id = id;
+        RETURN;
+    END IF;
+
+    IF new_follow_class_name IS NOT NULL THEN
+        -- Get the position of the class after which the new class should be added.
+        SELECT o.order_index INTO follow_class_index
+            FROM dhcp4_client_class AS c
+            INNER JOIN dhcp4_client_class_order AS o
+                ON c.id = o.class_id
+            WHERE c.name = new_follow_class_name;
+
+        IF follow_class_index IS NULL THEN
+            -- The class with a name specified with new_follow_class_name does
+            -- not exist.
+            RAISE EXCEPTION 'Class %s does not exist.', new_follow_class_name
+                USING ERRCODE = 'sql_routine_exception';
+        END IF;
+
+        -- We need to place the new class at the position of follow_class_index + 1.
+        -- There may be a class at this position already.
+        IF EXISTS(SELECT * FROM dhcp4_client_class_order WHERE order_index = follow_class_index + 1) THEN
+            -- There is a class at this position already. Let's move all classes
+            -- starting from this position by one to create a spot for the new
+            -- class.
+            UPDATE dhcp4_client_class_order
+                SET order_index = order_index + 1
+            WHERE order_index >= follow_class_index + 1;
+            -- TKM postgresql doesn't like order by here, does it matter?
+            -- ORDER BY order_index DESC;
+        END IF;
+
+    ELSE
+        -- A caller did not specify the new_follow_class_name value. Let's append the
+        -- new class at the end of the hierarchy.
+        SELECT MAX(order_index) INTO follow_class_index FROM dhcp4_client_class_order;
+        IF follow_class_index IS NULL THEN
+            -- Apparently, there are no classes. Let's start from 0.
+            follow_class_index = 0;
+        END IF;
+    END IF;
+
+    -- Check if moving the class doesn't break dependent classes.
+    IF EXISTS(
+        SELECT 1 FROM dhcp4_client_class_dependency AS d
+            INNER JOIN dhcp4_client_class_order AS o
+                ON d.class_id = o.class_id
+            WHERE d.dependency_id = id AND o.order_index < follow_class_index + 1
+        LIMIT 1
+    ) THEN
+        RAISE EXCEPTION 'Unable to move class with id %s because it would break its dependencies', id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+    -- whenever the dhcp4_client_class record is updated. Such update may include
+    -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+    -- This value will be later adjusted when dependencies are inserted.
+    -- TKM - note that ON CONFLICT requires PostgreSQL 9.5 or later.
+    UPDATE dhcp4_client_class_order
+        SET order_index = follow_class_index + 1,
+            depend_on_known_indirectly = l_depend_on_known_indirectly
+        WHERE class_id = id;
+    IF FOUND THEN
+        RETURN;
+    END IF;
+
+    INSERT INTO  dhcp4_client_class_order(class_id, order_index, depend_on_known_indirectly)
+        VALUES (id, follow_class_index + 1, false);
+    RETURN;
+END;$$;
+
+-- Replace setClientClass6Order():
+-- 1. l_depend_on_known_indirectly needs to be BOOL
+-- 2. follow_class_index needs to be BIGINT
+
+-- -----------------------------------------------------------------------
+-- Stored procedure positioning an inserted or updated client class
+-- within the class hierarchy, depending on the value of the
+-- new_follow_class_name parameter.
+--
+-- Parameters:
+-- - id id of the positioned class,
+-- - new_follow_class_name name of the class after which this class should be
+--   positioned within the class hierarchy.
+-- - old_follow_class_name previous name of the class after which this
+--   class was positioned within the class hierarchy.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION setClientClass6Order(id BIGINT,
+                                                new_follow_class_name VARCHAR(128),
+                                                old_follow_class_name VARCHAR(128))
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    -- Used to fetch class's current value for depend_on_known_indirectly
+    l_depend_on_known_indirectly BOOL := false;
+
+    -- Optionally set if the follow_class_name column value is specified.
+    follow_class_index BIGINT;
+BEGIN
+    -- Fetch the class's current value of depend_on_known_indirectly.
+    SELECT depend_on_known_indirectly INTO l_depend_on_known_indirectly
+        FROM dhcp6_client_class_order WHERE id = class_id;
+
+    -- Save it to the current session for use elsewhere during this transaction.
+    -- Note this does not work prior to Postgres 9.2 unless the variables are
+    -- defined in postgresql.conf. I think for now we put up with CB not supported
+    -- prior to 9.2 or we tell people how to edit the conf file.
+    PERFORM set_session_value('kea.depend_on_known_indirectly', l_depend_on_known_indirectly);
+
+    -- Bail if the class is updated without re-positioning.
+    IF(
+       l_depend_on_known_indirectly IS NOT NULL AND
+       ((new_follow_class_name IS NULL AND old_follow_class_name IS NULL) OR
+        (new_follow_class_name = old_follow_class_name))
+    ) THEN
+        -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+        -- whenever the dhcp6_client_class record is updated. Such update may include
+        -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+        -- This value will be later adjusted when dependencies are inserted.
+        -- TKM should we update the session value also or is it moot?
+        UPDATE dhcp6_client_class_order SET depend_on_known_indirectly = false
+            WHERE class_id = id;
+        RETURN;
+    END IF;
+
+    IF new_follow_class_name IS NOT NULL THEN
+        -- Get the position of the class after which the new class should be added.
+        SELECT o.order_index INTO follow_class_index
+            FROM dhcp6_client_class AS c
+            INNER JOIN dhcp6_client_class_order AS o
+                ON c.id = o.class_id
+            WHERE c.name = new_follow_class_name;
+
+        IF follow_class_index IS NULL THEN
+            -- The class with a name specified with new_follow_class_name does
+            -- not exist.
+            RAISE EXCEPTION 'Class %s does not exist.', new_follow_class_name
+                USING ERRCODE = 'sql_routine_exception';
+        END IF;
+
+        -- We need to place the new class at the position of follow_class_index + 1.
+        -- There may be a class at this position already.
+        IF EXISTS(SELECT * FROM dhcp6_client_class_order WHERE order_index = follow_class_index + 1) THEN
+            -- There is a class at this position already. Let's move all classes
+            -- starting from this position by one to create a spot for the new
+            -- class.
+            UPDATE dhcp6_client_class_order
+                SET order_index = order_index + 1
+            WHERE order_index >= follow_class_index + 1;
+            -- TKM postgresql doesn't like order by here, does it matter?
+            -- ORDER BY order_index DESC;
+        END IF;
+
+    ELSE
+        -- A caller did not specify the new_follow_class_name value. Let's append the
+        -- new class at the end of the hierarchy.
+        SELECT MAX(order_index) INTO follow_class_index FROM dhcp6_client_class_order;
+        IF follow_class_index IS NULL THEN
+            -- Apparently, there are no classes. Let's start from 0.
+            follow_class_index = 0;
+        END IF;
+    END IF;
+
+    -- Check if moving the class doesn't break dependent classes.
+    IF EXISTS(
+        SELECT 1 FROM dhcp6_client_class_dependency AS d
+            INNER JOIN dhcp6_client_class_order AS o
+                ON d.class_id = o.class_id
+            WHERE d.dependency_id = id AND o.order_index < follow_class_index + 1
+        LIMIT 1
+    ) THEN
+        RAISE EXCEPTION 'Unable to move class with id %s because it would break its dependencies', id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+    -- whenever the dhcp6_client_class record is updated. Such update may include
+    -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+    -- This value will be later adjusted when dependencies are inserted.
+    -- TKM - note that ON CONFLICT requires PostgreSQL 9.5 or later.
+    UPDATE dhcp6_client_class_order
+        SET order_index = follow_class_index + 1,
+            depend_on_known_indirectly = l_depend_on_known_indirectly
+        WHERE class_id = id;
+    IF FOUND THEN
+        RETURN;
+    END IF;
+
+    INSERT INTO  dhcp6_client_class_order(class_id, order_index, depend_on_known_indirectly)
+        VALUES (id, follow_class_index + 1, false);
+    RETURN;
+END;$$;
+
+-- Change primary key to composite, dependency table can have multiple rows
+-- per class id.
+ALTER TABLE dhcp4_client_class_dependency DROP CONSTRAINT dhcp4_client_class_dependency_pkey;
+ALTER TABLE dhcp4_client_class_dependency ADD PRIMARY KEY(class_id, dependency_id);
+
+ALTER TABLE dhcp6_client_class_dependency DROP CONSTRAINT dhcp6_client_class_dependency_pkey;
+ALTER TABLE dhcp6_client_class_dependency ADD PRIMARY KEY(class_id, dependency_id);
+
+-- Replace triggers that verify class dependency.
+-- Because they are BEFORE INSERT triggers they need to return NEW not NULL.
+-- -----------------------------------------------------------------------
+-- Trigger verifying if class dependency is met. It includes checking
+-- if referenced classes exist, are associated with the same server
+-- or all servers, and are defined before the class specified with
+-- class_id.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp4_client_class_check_dependency_BINS()
+    RETURNS trigger AS $dhcp4_client_class_check_dependency_BINS$
+BEGIN
+    PERFORM checkDHCPv4ClientClassDependency(NEW.class_id, NEW.dependency_id);
+    RETURN NEW;
+END;
+$dhcp4_client_class_check_dependency_BINS$
+LANGUAGE plpgsql;
+
+-- -----------------------------------------------------------------------
+-- Trigger verifying if class dependency is met. It includes checking
+-- if referenced classes exist, are associated with the same server
+-- or all servers, and are defined before the class specified with
+-- class_id.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp6_client_class_check_dependency_BINS()
+    RETURNS trigger AS $dhcp6_client_class_check_dependency_BINS$
+BEGIN
+    PERFORM checkDHCPv6ClientClassDependency(NEW.class_id, NEW.dependency_id);
+    RETURN NEW;
+END;
+$dhcp6_client_class_check_dependency_BINS$
+LANGUAGE plpgsql;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '10', minor = '0';
+
+-- This line concludes the schema upgrade to version 10.0.
+
+-- This line starts the schema upgrade to version 11.0.
+
+-- Replace createOptionAuditDHCP6() with a version corrected
+-- where clause when scope is 6 (i.e. PD pool)
+--
+-- -----------------------------------------------------
+--
+-- Stored procedure which updates modification timestamp of
+-- a parent object when an option is modified.
+--
+-- The following parameters are passed to the procedure:
+-- - modification_type: "create", "update" or "delete"
+-- - scope_id: identifier of the option scope, e.g.
+--   global, subnet specific etc. See dhcp_option_scope
+--   for specific values.
+-- - option_id: identifier of the option.
+-- - p_subnet_id: identifier of the subnet if the option
+--   belongs to the subnet.
+-- - host_id: identifier of the host if the option
+-- - belongs to the host.
+-- - network_name: shared network name if the option
+--   belongs to the shared network.
+-- - pool_id: identifier of the pool if the option
+--   belongs to the pool.
+-- - pd_pool_id: identifier of the pool if the option
+--   belongs to the pd pool.
+-- - p_modification_ts: modification timestamp of the
+--   option.
+--   Some arguments are prefixed with "p_" to avoid ambiguity
+--   with column names in SQL statements. PostgreSQL does not
+--   allow table aliases to be used with column names in update
+--   set expressions.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createOptionAuditDHCP6(modification_type VARCHAR,
+                                                  scope_id SMALLINT,
+                                                  option_id INT,
+                                                  p_subnet_id BIGINT,
+                                                  host_id INT,
+                                                  network_name VARCHAR,
+                                                  pool_id BIGINT,
+                                                  pd_pool_id BIGINT,
+                                                  p_modification_ts TIMESTAMP WITH TIME ZONE)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    -- These variables will hold shared network id and subnet id that
+    -- we will select.
+    snid BIGINT;
+    sid BIGINT;
+    cascade_transaction BOOLEAN;
+BEGIN
+    -- Cascade transaction flag is set to true to prevent creation of
+    -- the audit entries for the options when the options are
+    -- created as part of the parent object creation or update.
+    -- For example: when the option is added as part of the subnet
+    -- addition, the cascade transaction flag is equal to true. If
+    -- the option is added into the existing subnet the cascade
+    -- transaction is equal to false. Note that depending on the option
+    -- scope the audit entry will contain the object_type value
+    -- of the parent object to cause the server to replace the
+    -- entire subnet. The only case when the object_type will be
+    -- set to 'dhcp6_options' is when a global option is added.
+    -- Global options do not have the owner.
+
+    cascade_transaction := get_session_boolean('kea.cascade_transaction');
+    IF cascade_transaction = false THEN
+        -- todo: host manager hasn't been updated to use audit
+        -- mechanisms so ignore host specific options for now.
+        IF scope_id = 0 THEN
+            -- If a global option is added or modified, create audit
+            -- entry for the 'dhcp6_options' table.
+            PERFORM createAuditEntryDHCP6('dhcp6_options', option_id, modification_type);
+        ELSEIF scope_id = 1 THEN
+            -- If subnet specific option is added or modified, update
+            -- the modification timestamp of this subnet to allow the
+            -- servers to refresh the subnet information. This will
+            -- also result in creating an audit entry for this subnet.
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = p_subnet_id;
+        ELSEIF scope_id = 4 THEN
+            -- If shared network specific option is added or modified,
+            -- update the modification timestamp of this shared network
+            -- to allow the servers to refresh the shared network
+            -- information. This will also result in creating an
+            -- audit entry for this shared network.
+           SELECT id INTO snid FROM dhcp6_shared_network WHERE name = network_name LIMIT 1;
+           UPDATE dhcp6_shared_network SET modification_ts = p_modification_ts
+                WHERE id = snid;
+        ELSEIF scope_id = 5 THEN
+            -- If pool specific option is added or modified, update
+            -- the modification timestamp of the owning subnet.
+            SELECT dhcp6_pool.subnet_id INTO sid FROM dhcp6_pool WHERE id = pool_id;
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        ELSEIF scope_id = 6 THEN
+            -- If pd pool specific option is added or modified, create
+            -- audit entry for the subnet which this pool belongs to.
+            SELECT dhcp6_pd_pool.subnet_id INTO sid FROM dhcp6_pd_pool WHERE id = pd_pool_id;
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        END IF;
+    END IF;
+    RETURN;
+END;$$;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '11', minor = '0';
+
+-- This line concludes the schema upgrade to version 11.0.
+
+-- This line starts the schema upgrade to version 12.0.
+
+-- Modify shared-network-name foreign key constraint on dhcp4_subnet to not perform
+-- the update when the network is deleted the cascaded update will not execute
+-- dhcp4_subnet update trigger leaving the updated subnets without audit_entries.
+ALTER TABLE dhcp4_subnet
+    DROP CONSTRAINT fk_dhcp4_subnet_shared_network,
+    ADD CONSTRAINT fk_dhcp4_subnet_shared_network FOREIGN KEY (shared_network_name)
+         REFERENCES dhcp4_shared_network (name)
+         ON DELETE NO ACTION ON UPDATE NO ACTION;
+
+-- Modify BEFORE delete trigger function on dhcp4_shared_network to explicitly
+-- update dhcp4_subnets. This ensures there are audit entries for updated
+-- subnets.
+-- Trigger function for dhcp4_shared_network_BDEL called BEFORE DELETE on dhcp4_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp4_shared_network_BDEL() RETURNS TRIGGER AS $dhcp4_shared_network_BDEL$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_shared_network', OLD.id, 'delete');
+    -- Explicitly update subnets now rather than via foreign key constraint, this ensures the
+    -- audit entries for subnets will preceded that of the shared-network, keeping the order
+    -- of the entries the same as they are for MySQL.
+    UPDATE dhcp4_subnet SET shared_network_name = NULL WHERE shared_network_name = OLD.name;
+    DELETE FROM dhcp4_options WHERE shared_network_name = OLD.name;
+    RETURN OLD;
+END;
+$dhcp4_shared_network_BDEL$
+LANGUAGE plpgsql;
+
+-- Modify shared-network-name foreign key constraint on dhcp6_subnet to not perform
+-- the update when the network is deleted the cascaded update will not execute
+-- dhcp6_subnet update trigger leaving the updated subnets without audit_entries.
+ALTER TABLE dhcp6_subnet
+    DROP CONSTRAINT fk_dhcp6_subnet_shared_network,
+    ADD CONSTRAINT fk_dhcp6_subnet_shared_network FOREIGN KEY (shared_network_name)
+         REFERENCES dhcp6_shared_network (name)
+         ON DELETE NO ACTION ON UPDATE NO ACTION;
+
+-- Modify BEFORE delete trigger function on dhcp6_shared_network to explicitly
+-- update dhcp6_subnets. This ensures there are audit entries for updated
+-- subnets.
+-- Trigger function for dhcp6_shared_network_BDEL called BEFORE DELETE on dhcp6_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp6_shared_network_BDEL() RETURNS TRIGGER AS $dhcp6_shared_network_BDEL$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_shared_network', OLD.id, 'delete');
+    -- Explicitly update subnets now rather than via foreign key constraint, this ensures the
+    -- audit entries for subnets will preceded that of the shared-network, keeping the order
+    -- of the entries the same as they are for MySQL.
+    UPDATE dhcp6_subnet SET shared_network_name = NULL WHERE shared_network_name = OLD.name;
+    DELETE FROM dhcp6_options WHERE shared_network_name = OLD.name;
+    RETURN OLD;
+END;
+$dhcp6_shared_network_BDEL$
+LANGUAGE plpgsql;
+
+-- Add user_context column to client class tables.
+ALTER TABLE dhcp4_client_class ADD COLUMN user_context JSON DEFAULT NULL;
+ALTER TABLE dhcp6_client_class ADD COLUMN user_context JSON DEFAULT NULL;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '12', minor = '0';
+
+-- This line concludes the schema upgrade to version 12.0.
+
+-- This line starts the schema upgrade to version 13.0.
+
+-- JSON functions --
+
+-- Helper function that avoids a casting error when the string
+-- presumed to be in JSON format, is empty.
+CREATE OR REPLACE FUNCTION json_cast(IN json_candidate TEXT)
+RETURNS JSON
+AS $$
+BEGIN
+    IF LENGTH(json_candidate) = 0 THEN
+        RETURN '{}'::json;
+    END IF;
+    RETURN json_candidate::json;
+END;
+$$ LANGUAGE plpgsql;
+
+-- Function that establishes whether JSON functions are supported.
+-- They should be provided with PostgreSQL >= 9.4.
+CREATE OR REPLACE FUNCTION isJsonSupported()
+RETURNS BOOLEAN
+AS $$
+BEGIN
+    IF get_session_value('json_supported') IS NULL THEN
+        IF (SELECT proname FROM pg_proc WHERE proname = 'json_extract_path') = 'json_extract_path' THEN
+            PERFORM set_session_value('kea.json_supported', true);
+        ELSE
+            PERFORM set_session_value('kea.json_supported', false);
+        END IF;
+    END IF;
+    RETURN get_session_value('kea.json_supported');
+END
+$$ LANGUAGE plpgsql;
+
+-- Schema changes related to lease limiting start here. --
+
+-- Recreate the triggers that update the leaseX_stat tables as stored procedures. --
+
+CREATE OR REPLACE FUNCTION lease4_AINS_lease4_stat(IN new_state BIGINT,
+                                                   IN new_subnet_id BIGINT)
+RETURNS VOID
+AS $$
+BEGIN
+    IF new_state = 0 OR new_state = 1 THEN
+        -- Update the state count if it exists.
+        UPDATE lease4_stat SET leases = leases + 1
+            WHERE subnet_id = new_subnet_id AND state = new_state;
+
+        -- Insert the state count record if it does not exist.
+        IF NOT FOUND THEN
+            INSERT INTO lease4_stat VALUES (new_subnet_id, new_state, 1);
+        END IF;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease4_AUPD_lease4_stat(IN old_state BIGINT,
+                                                   IN old_subnet_id BIGINT,
+                                                   IN new_state BIGINT,
+                                                   IN new_subnet_id BIGINT)
+RETURNS VOID
+AS $$
+BEGIN
+    IF old_subnet_id != new_subnet_id OR old_state != new_state THEN
+        IF old_state = 0 OR old_state = 1 THEN
+            -- Decrement the old state count if record exists.
+            UPDATE lease4_stat
+                SET leases = GREATEST(leases - 1, 0)
+                WHERE subnet_id = old_subnet_id AND state = old_state;
+        END IF;
+
+        IF new_state = 0 OR new_state = 1 THEN
+            -- Increment the new state count if record exists.
+            UPDATE lease4_stat SET leases = leases + 1
+                WHERE subnet_id = new_subnet_id AND state = new_state;
+
+            -- Insert new state record if it does not exist.
+            IF NOT FOUND THEN
+                INSERT INTO lease4_stat VALUES (new_subnet_id, new_state, 1);
+            END IF;
+        END IF;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease4_ADEL_lease4_stat(IN old_state BIGINT,
+                                                   IN old_subnet_id BIGINT)
+RETURNS VOID
+AS $$
+BEGIN
+    IF old_state = 0 OR old_state = 1 THEN
+        -- Decrement the state count if record exists.
+        UPDATE lease4_stat
+            SET leases = GREATEST(leases - 1, 0)
+            WHERE subnet_id = old_subnet_id AND old_state = state;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_AINS_lease6_stat(IN new_state BIGINT,
+                                                   IN new_subnet_id BIGINT,
+                                                   IN new_lease_type SMALLINT)
+RETURNS VOID
+AS $$
+BEGIN
+    IF new_state = 0 OR new_state = 1 THEN
+        -- Update the state count if it exists.
+        UPDATE lease6_stat SET leases = leases + 1
+            WHERE subnet_id = new_subnet_id AND lease_type = new_lease_type
+            AND state = new_state;
+
+        -- Insert the state count record if it does not exist.
+        IF NOT FOUND THEN
+            INSERT INTO lease6_stat VALUES (new_subnet_id, new_lease_type, new_state, 1);
+        END IF;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_AUPD_lease6_stat(IN old_state BIGINT,
+                                                   IN old_subnet_id BIGINT,
+                                                   IN old_lease_type SMALLINT,
+                                                   IN new_state BIGINT,
+                                                   IN new_subnet_id BIGINT,
+                                                   IN new_lease_type SMALLINT)
+RETURNS VOID
+AS $$
+BEGIN
+    IF old_subnet_id != new_subnet_id OR
+       old_lease_type != new_lease_type OR
+       old_state != new_state THEN
+        IF old_state = 0 OR old_state = 1 THEN
+            -- Decrement the old state count if record exists.
+            UPDATE lease6_stat
+                SET leases = GREATEST(leases - 1, 0)
+                WHERE subnet_id = old_subnet_id AND lease_type = old_lease_type
+                AND state = old_state;
+        END IF;
+
+        IF new_state = 0 OR new_state = 1 THEN
+            -- Increment the new state count if record exists
+            UPDATE lease6_stat SET leases = leases + 1
+                WHERE subnet_id = new_subnet_id AND lease_type = new_lease_type
+                AND state = new_state;
+
+            -- Insert new state record if it does not exist
+            IF NOT FOUND THEN
+                INSERT INTO lease6_stat
+                VALUES (new_subnet_id, new_lease_type, new_state, 1);
+            END IF;
+        END IF;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_ADEL_lease6_stat(IN old_state BIGINT,
+                                                   IN old_subnet_id BIGINT,
+                                                   IN old_lease_type SMALLINT)
+RETURNS VOID
+AS $$
+BEGIN
+    IF old_state = 0 OR old_state = 1 THEN
+        -- Decrement the state count if record exists
+        UPDATE lease6_stat
+            SET leases = GREATEST(leases - 1, 0)
+            WHERE subnet_id = old_subnet_id AND lease_type = old_lease_type
+            AND state = old_state;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+-- Create tables that contain the number of active leases. --
+
+CREATE TABLE lease4_stat_by_client_class (
+    client_class VARCHAR(128) NOT NULL PRIMARY KEY,
+    leases BIGINT NOT NULL
+);
+
+CREATE TABLE lease6_stat_by_client_class (
+    client_class VARCHAR(128) NOT NULL,
+    lease_type SMALLINT NOT NULL,
+    leases BIGINT NOT NULL,
+    PRIMARY KEY (client_class, lease_type),
+    CONSTRAINT fk_lease6_stat_by_client_class_lease_type FOREIGN KEY (lease_type)
+        REFERENCES lease6_types (lease_type)
+);
+
+-- Create procedures to be called for each row in after-event triggers for
+-- INSERT, UPDATE and DELETE on lease tables.
+
+CREATE OR REPLACE FUNCTION lease4_AINS_lease4_stat_by_client_class(IN new_state BIGINT,
+                                                                   IN new_user_context TEXT)
+RETURNS VOID
+AS $$
+DECLARE
+    class VARCHAR(128);
+BEGIN
+    -- Only state 0 is needed for lease limiting.
+    IF new_state = 0 THEN
+        -- Dive into client classes.
+        FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(new_user_context)->'ISC'->'client-classes') LOOP
+            SELECT TRIM('"' FROM class) INTO class;
+
+            -- Upsert to increment the lease count.
+            UPDATE lease4_stat_by_client_class SET leases = leases + 1
+                WHERE client_class = class;
+            IF NOT FOUND THEN
+                INSERT INTO lease4_stat_by_client_class VALUES (class, 1);
+            END IF;
+        END LOOP;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease4_AUPD_lease4_stat_by_client_class(IN old_state BIGINT,
+                                                                   IN old_user_context TEXT,
+                                                                   IN new_state BIGINT,
+                                                                   IN new_user_context TEXT)
+RETURNS VOID
+AS $$
+DECLARE
+    old_client_classes TEXT;
+    new_client_classes TEXT;
+    class VARCHAR(128);
+    length INT;
+    i INT;
+BEGIN
+    SELECT json_cast(old_user_context)->'ISC'->'client-classes' INTO old_client_classes;
+    SELECT json_cast(new_user_context)->'ISC'->'client-classes' INTO new_client_classes;
+
+    IF old_state != new_state OR old_client_classes != new_client_classes THEN
+        -- Check if it's moving away from a counted state.
+        IF old_state = 0 THEN
+            -- Dive into client classes.
+            FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(old_client_classes)) LOOP
+                SELECT TRIM('"' FROM class) INTO class;
+
+                -- Decrement the lease count if the record exists.
+                UPDATE lease4_stat_by_client_class SET leases = GREATEST(leases - 1, 0)
+                    WHERE client_class = class;
+            END LOOP;
+        END IF;
+
+        -- Check if it's moving into a counted state.
+        IF new_state = 0 THEN
+            -- Dive into client classes.
+            FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(new_client_classes)) LOOP
+                SELECT TRIM('"' FROM class) INTO class;
+
+                -- Upsert to increment the lease count.
+                UPDATE lease4_stat_by_client_class SET leases = leases + 1
+                    WHERE client_class = class;
+                IF NOT FOUND THEN
+                    INSERT INTO lease4_stat_by_client_class VALUES (class, 1);
+                END IF;
+            END LOOP;
+        END IF;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease4_ADEL_lease4_stat_by_client_class(IN old_state BIGINT,
+                                                                   IN old_user_context TEXT)
+RETURNS VOID
+AS $$
+DECLARE
+    class VARCHAR(128);
+BEGIN
+    -- Only state 0 is accounted for in lease limiting.
+    IF old_state = 0 THEN
+        -- Dive into client classes.
+        FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(old_user_context)->'ISC'->'client-classes') LOOP
+            SELECT TRIM('"' FROM class) INTO class;
+
+            -- Decrement the lease count if the record exists.
+            UPDATE lease4_stat_by_client_class SET leases = GREATEST(leases - 1, 0)
+                WHERE client_class = class;
+        END LOOP;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_AINS_lease6_stat_by_client_class(IN new_state BIGINT,
+                                                                   IN new_user_context TEXT,
+                                                                   IN new_lease_type SMALLINT)
+RETURNS VOID
+AS $$
+DECLARE
+    client_classes TEXT;
+    class VARCHAR(128);
+    length INT;
+    i INT;
+BEGIN
+    -- Only state 0 is needed for lease limiting.
+    IF new_state = 0 THEN
+        -- Dive into client classes.
+        FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(new_user_context)->'ISC'->'client-classes') LOOP
+            SELECT TRIM('"' FROM class) INTO class;
+
+            -- Upsert to increment the lease count.
+            UPDATE lease6_stat_by_client_class SET leases = leases + 1
+                WHERE client_class = class AND lease_type = new_lease_type;
+            IF NOT FOUND THEN
+                INSERT INTO lease6_stat_by_client_class VALUES (class, new_lease_type, 1);
+            END IF;
+        END LOOP;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_AUPD_lease6_stat_by_client_class(IN old_state BIGINT,
+                                                                   IN old_user_context TEXT,
+                                                                   IN old_lease_type SMALLINT,
+                                                                   IN new_state BIGINT,
+                                                                   IN new_user_context TEXT,
+                                                                   IN new_lease_type SMALLINT)
+RETURNS VOID
+AS $$
+DECLARE
+    old_client_classes TEXT;
+    new_client_classes TEXT;
+    class VARCHAR(128);
+    length INT;
+    i INT;
+BEGIN
+    SELECT json_cast(old_user_context)->'ISC'->'client-classes' INTO old_client_classes;
+    SELECT json_cast(new_user_context)->'ISC'->'client-classes' INTO new_client_classes;
+
+    IF old_state != new_state OR old_client_classes != new_client_classes OR old_lease_type != new_lease_type THEN
+        -- Check if it's moving away from a counted state.
+        IF old_state = 0 THEN
+            -- Dive into client classes.
+            FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(old_client_classes)) LOOP
+                SELECT TRIM('"' FROM class) INTO class;
+
+                -- Decrement the lease count if the record exists.
+                UPDATE lease6_stat_by_client_class SET leases = GREATEST(leases - 1, 0)
+                    WHERE client_class = class AND lease_type = old_lease_type;
+            END LOOP;
+        END IF;
+
+        -- Check if it's moving into a counted state.
+        IF new_state = 0 THEN
+            -- Dive into client classes.
+            FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(new_client_classes)) LOOP
+                SELECT TRIM('"' FROM class) INTO class;
+
+                -- Upsert to increment the lease count.
+                UPDATE lease6_stat_by_client_class SET leases = leases + 1
+                    WHERE client_class = class AND lease_type = new_lease_type;
+                IF NOT FOUND THEN
+                    INSERT INTO lease6_stat_by_client_class VALUES (class, new_lease_type, 1);
+                END IF;
+            END LOOP;
+        END IF;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_ADEL_lease6_stat_by_client_class(IN old_state BIGINT,
+                                                                   IN old_user_context TEXT,
+                                                                   IN old_lease_type SMALLINT)
+RETURNS VOID
+AS $$
+DECLARE
+    client_classes VARCHAR(1024);
+    class VARCHAR(128);
+    length INT;
+    i INT;
+BEGIN
+    -- Only state 0 is accounted for in lease limiting. But check both states to be consistent with lease6_stat.
+    IF old_state = 0 THEN
+        -- Dive into client classes.
+        FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(old_user_context)->'ISC'->'client-classes') LOOP
+            SELECT TRIM('"' FROM class) INTO class;
+
+            -- Decrement the lease count if the record exists.
+            UPDATE lease6_stat_by_client_class SET leases = GREATEST(leases - 1, 0)
+                WHERE client_class = class AND lease_type = old_lease_type;
+        END LOOP;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+-- Recreate the after-event triggers for INSERT, UPDATE and DELETE on lease tables to call the --
+-- stored procedures above in pairs of two: for client classes and for subnets. --
+
+DROP TRIGGER IF EXISTS stat_lease4_insert ON lease4;
+
+CREATE OR REPLACE FUNCTION func_lease4_AINS()
+RETURNS trigger AS $lease4_AINS$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease4_AINS_lease4_stat_by_client_class(NEW.state, NEW.user_context);
+    END IF;
+    PERFORM lease4_AINS_lease4_stat(NEW.state, NEW.subnet_id);
+    RETURN NULL;
+END;
+$lease4_AINS$ LANGUAGE plpgsql;
+
+CREATE TRIGGER lease4_AINS AFTER INSERT ON lease4
+    FOR EACH ROW EXECUTE PROCEDURE func_lease4_AINS();
+
+DROP TRIGGER IF EXISTS stat_lease4_update ON lease4;
+
+CREATE OR REPLACE FUNCTION func_lease4_AUPD()
+RETURNS trigger AS $lease4_AUPD$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease4_AUPD_lease4_stat_by_client_class(OLD.state, OLD.user_context, NEW.state, NEW.user_context);
+    END IF;
+    PERFORM lease4_AUPD_lease4_stat(OLD.state, OLD.subnet_id, NEW.state, NEW.subnet_id);
+    RETURN NULL;
+END;
+$lease4_AUPD$ LANGUAGE plpgsql;
+
+CREATE TRIGGER lease4_AUPD AFTER UPDATE ON lease4
+    FOR EACH ROW EXECUTE PROCEDURE func_lease4_AUPD();
+
+DROP TRIGGER IF EXISTS stat_lease4_delete ON lease4;
+
+CREATE OR REPLACE FUNCTION func_lease4_ADEL()
+RETURNS trigger AS $lease4_ADEL$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease4_ADEL_lease4_stat_by_client_class(OLD.state, OLD.user_context);
+    END IF;
+    PERFORM lease4_ADEL_lease4_stat(OLD.state, OLD.subnet_id);
+    RETURN NULL;
+END;
+$lease4_ADEL$ LANGUAGE plpgsql;
+
+CREATE TRIGGER lease4_ADEL AFTER DELETE ON lease4
+    FOR EACH ROW EXECUTE PROCEDURE func_lease4_ADEL();
+
+DROP TRIGGER IF EXISTS stat_lease6_insert ON lease6;
+
+CREATE OR REPLACE FUNCTION func_lease6_AINS()
+RETURNS trigger AS $lease6_AINS$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease6_AINS_lease6_stat_by_client_class(NEW.state, NEW.user_context, NEW.lease_type);
+    END IF;
+    PERFORM lease6_AINS_lease6_stat(NEW.state, NEW.subnet_id, NEW.lease_type);
+    RETURN NULL;
+END;
+$lease6_AINS$ LANGUAGE plpgsql;
+
+CREATE TRIGGER lease6_AINS AFTER INSERT ON lease6
+    FOR EACH ROW EXECUTE PROCEDURE func_lease6_AINS();
+
+DROP TRIGGER IF EXISTS stat_lease6_update ON lease6;
+
+CREATE OR REPLACE FUNCTION func_lease6_AUPD()
+RETURNS trigger AS $lease6_AUPD$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease6_AUPD_lease6_stat_by_client_class(OLD.state, OLD.user_context, OLD.lease_type, NEW.state, NEW.user_context, NEW.lease_type);
+    END IF;
+    PERFORM lease6_AUPD_lease6_stat(OLD.state, OLD.subnet_id, OLD.lease_type, NEW.state, NEW.subnet_id, NEW.lease_type);
+    RETURN NULL;
+END;
+$lease6_AUPD$ LANGUAGE plpgsql;
+
+CREATE TRIGGER lease6_AUPD AFTER UPDATE ON lease6
+    FOR EACH ROW EXECUTE PROCEDURE func_lease6_AUPD();
+
+DROP TRIGGER IF EXISTS stat_lease6_delete ON lease6;
+
+CREATE OR REPLACE FUNCTION func_lease6_ADEL()
+RETURNS trigger AS $lease6_ADEL$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease6_ADEL_lease6_stat_by_client_class(OLD.state, OLD.user_context, OLD.lease_type);
+    END IF;
+    PERFORM lease6_ADEL_lease6_stat(OLD.state, OLD.subnet_id, OLD.lease_type);
+    RETURN NULL;
+END;
+$lease6_ADEL$ LANGUAGE plpgsql;
+
+CREATE TRIGGER lease6_ADEL AFTER DELETE ON lease6
+    FOR EACH ROW EXECUTE PROCEDURE func_lease6_ADEL();
+
+-- Create functions that return an empty TEXT if all limits allow for more leases, or otherwise a
+-- TEXT in one of the following JSON formats detailing the limit that was reached:
+-- { "limit-type": "client-class", "name": foo, "lease-type": "address", "limit": 2, "count": 2 }
+-- { "limit-type": "subnet", "id": 1, "lease-type": "IA_PD", "limit": 2, "count": 2 }
+-- The following format for user_context is assumed:
+-- { "ISC": { "limits": { "client-classes": [ { "name": "foo", "address-limit": 2, "prefix-limit": 1 } ],
+--                        "subnet": { "id": 1, "address-limit": 2, "prefix-limit": 1 } } } }
+
+CREATE OR REPLACE FUNCTION checkLease4Limits(user_context TEXT)
+RETURNS TEXT
+AS $$
+DECLARE
+    class TEXT;
+    name VARCHAR(255);
+    sid INT;
+    lease_limit INT;
+    lease_count INT;
+BEGIN
+    -- Dive into client class limits.
+    FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(user_context)->'ISC'->'limits'->'client-classes') LOOP
+        SELECT TRIM('"' FROM (json_cast(class)->'name')::text) INTO name;
+        SELECT json_cast(class)->'address-limit' INTO lease_limit;
+
+        IF lease_limit IS NOT NULL THEN
+            -- Get the lease count for this client class.
+            SELECT leases FROM lease4_stat_by_client_class INTO lease_count WHERE client_class = name;
+            IF lease_count IS NULL THEN
+                lease_count := 0;
+            END IF;
+
+            -- Compare. Return immediately if the limit is surpassed.
+            IF lease_limit <= lease_count THEN
+                RETURN CONCAT('address limit ', lease_limit, ' for client class "', name, '", current lease count ', lease_count);
+            END IF;
+        END IF;
+    END LOOP;
+
+    -- Dive into subnet limits.
+    SELECT json_cast(user_context)->'ISC'->'limits'->'subnet'->'id' INTO sid;
+    SELECT json_cast(user_context)->'ISC'->'limits'->'subnet'->'address-limit' INTO lease_limit;
+
+    IF lease_limit IS NOT NULL THEN
+        -- Get the lease count for this client class.
+        SELECT leases FROM lease4_stat WHERE subnet_id = sid AND state = 0 INTO lease_count;
+        IF lease_count IS NULL THEN
+            lease_count := 0;
+        END IF;
+
+        -- Compare. Return immediately if the limit is surpassed.
+        IF lease_limit <= lease_count THEN
+            RETURN CONCAT('address limit ', lease_limit, ' for subnet ID ', sid, ', current lease count ', lease_count);
+        END IF;
+    END IF;
+
+    RETURN '';
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION checkLease6Limits(user_context TEXT)
+RETURNS TEXT
+AS $$
+DECLARE
+    class TEXT;
+    name VARCHAR(255);
+    sid INT;
+    lease_limit INT;
+    lease_count INT;
+BEGIN
+    -- Dive into client class limits.
+    FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(user_context)->'ISC'->'limits'->'client-classes') LOOP
+        SELECT TRIM('"' FROM (json_cast(class)->'name')::text) INTO name;
+        SELECT json_cast(class)->'address-limit' INTO lease_limit;
+
+        IF lease_limit IS NOT NULL THEN
+            -- Get the address count for this client class.
+            SELECT leases FROM lease6_stat_by_client_class WHERE client_class = name AND lease_type = 0 INTO lease_count;
+            IF lease_count IS NULL THEN
+                lease_count := 0;
+            END IF;
+
+            -- Compare. Return immediately if the limit is surpassed.
+            IF lease_limit <= lease_count THEN
+                RETURN CONCAT('address limit ', lease_limit, ' for client class "', name, '", current lease count ', lease_count);
+            END IF;
+        END IF;
+
+        SELECT json_cast(class)->'prefix-limit' INTO lease_limit;
+        IF lease_limit IS NOT NULL THEN
+            -- Get the prefix count for this client class.
+            SELECT leases FROM lease6_stat_by_client_class WHERE client_class = name AND lease_type = 2 INTO lease_count;
+            IF lease_count IS NULL THEN
+                lease_count := 0;
+            END IF;
+
+            -- Compare. Return immediately if the limit is surpassed.
+            IF lease_limit <= lease_count THEN
+                RETURN CONCAT('prefix limit ', lease_limit, ' for client class "', name, '", current lease count ', lease_count);
+            END IF;
+        END IF;
+    END LOOP;
+
+    -- Dive into subnet limits.
+    SELECT json_cast(user_context)->'ISC'->'limits'->'subnet'->'id' INTO sid;
+    SELECT json_cast(user_context)->'ISC'->'limits'->'subnet'->'address-limit' INTO lease_limit;
+    IF lease_limit IS NOT NULL THEN
+        -- Get the lease count for this subnet.
+        SELECT leases FROM lease6_stat WHERE subnet_id = sid AND lease_type = 0 AND state = 0 INTO lease_count;
+        IF lease_count IS NULL THEN
+            lease_count := 0;
+        END IF;
+
+        -- Compare. Return immediately if the limit is surpassed.
+        IF lease_limit <= lease_count THEN
+            RETURN CONCAT('address limit ', lease_limit, ' for subnet ID ', sid, ', current lease count ', lease_count);
+        END IF;
+    END IF;
+    SELECT json_cast(user_context)->'ISC'->'limits'->'subnet'->'prefix-limit' INTO lease_limit;
+    IF lease_limit IS NOT NULL THEN
+        -- Get the lease count for this client class.
+        SELECT leases FROM lease6_stat WHERE subnet_id = sid AND lease_type = 2 AND state = 0 INTO lease_count;
+        IF lease_count IS NULL THEN
+            lease_count := 0;
+        END IF;
+
+        -- Compare. Return immediately if the limit is surpassed.
+        IF lease_limit <= lease_count THEN
+            RETURN CONCAT('prefix limit ', lease_limit, ' for subnet ID ', sid, ', current lease count ', lease_count);
+        END IF;
+    END IF;
+
+    RETURN '';
+END;
+$$ LANGUAGE plpgsql;
+
+-- Improve hosts indexes for better performance of global reservations
+-- Create new index that uses only dhcp_identifier.
+CREATE INDEX key_dhcp_identifier on hosts (dhcp_identifier, dhcp_identifier_type);
+
+-- Modify existing indexes to include subnet_id values of 0, so index is also used
+-- for global reservations.
+DROP INDEX IF EXISTS key_dhcp4_identifier_subnet_id;
+CREATE UNIQUE INDEX key_dhcp4_identifier_subnet_id ON hosts
+        (dhcp_identifier ASC, dhcp_identifier_type ASC, dhcp4_subnet_id ASC)
+    WHERE (dhcp4_subnet_id IS NOT NULL);
+
+DROP INDEX IF EXISTS key_dhcp6_identifier_subnet_id;
+CREATE UNIQUE INDEX key_dhcp6_identifier_subnet_id ON hosts
+        (dhcp_identifier ASC, dhcp_identifier_type ASC, dhcp6_subnet_id ASC)
+    WHERE (dhcp6_subnet_id IS NOT NULL);
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '13', minor = '0';
+
+-- This line concludes the schema upgrade to version 13.0.
+
+-- This line starts the schema upgrade to version 14.0.
+
+-- Add cancelled (aka never-send) column to option tables.
+
+ALTER TABLE dhcp4_options ADD COLUMN cancelled BOOLEAN NOT NULL DEFAULT 'f';
+ALTER TABLE dhcp6_options ADD COLUMN cancelled BOOLEAN NOT NULL DEFAULT 'f';
+
+-- Add offer_lifetime column to v4 tables.
+ALTER TABLE dhcp4_shared_network
+    ADD COLUMN offer_lifetime BIGINT DEFAULT NULL;
+
+ALTER TABLE dhcp4_subnet
+    ADD COLUMN offer_lifetime BIGINT DEFAULT NULL;
+
+ALTER TABLE dhcp4_client_class
+    ADD COLUMN offer_lifetime BIGINT DEFAULT NULL;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '14', minor = '0';
+
+-- This line concludes the schema upgrade to version 14.0.
+
+-- This line starts the schema upgrade to version 15.0.
+
+-- Add relay and remote id columns to DHCPv4 leases.
+--
+-- Note: these columns are only used for indexes, in particular they are
+-- not exported by lease4 dump as values are also in the user context
+ALTER TABLE lease4
+    ADD COLUMN relay_id BYTEA DEFAULT NULL,
+    ADD COLUMN remote_id BYTEA DEFAULT NULL;
+
+-- Create relay and remote id indexes.
+CREATE INDEX lease4_by_relay_id ON lease4 (relay_id);
+CREATE INDEX lease4_by_remote_id ON lease4 (remote_id);
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '15', minor = '0';
+
+-- This line concludes the schema upgrade to version 15.0.
+
+-- This line starts the schema upgrade to version 16.0.
+
+-- Add the allocator column to the DHCPv4 tables.
+ALTER TABLE dhcp4_subnet ADD COLUMN allocator TEXT DEFAULT NULL;
+ALTER TABLE dhcp4_shared_network ADD COLUMN allocator TEXT DEFAULT NULL;
+
+-- Add allocator and pd_allocator to the DHCPv6 subnet tables.
+ALTER TABLE dhcp6_subnet ADD COLUMN allocator TEXT DEFAULT NULL;
+ALTER TABLE dhcp6_subnet ADD COLUMN pd_allocator TEXT DEFAULT NULL;
+
+-- Add allocator and pd_allocator to the DHCPv6 shared network tables.
+ALTER TABLE dhcp6_shared_network ADD COLUMN allocator TEXT DEFAULT NULL;
+ALTER TABLE dhcp6_shared_network ADD COLUMN pd_allocator TEXT DEFAULT NULL;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '16', minor = '0';
+
+-- This line concludes the schema upgrade to version 16.0.
+
+-- This line starts the schema upgrade to version 17.0.
+
+UPDATE lease6 SET duid = E'\\x000000' WHERE duid = E'\\x00';
+
+-- Add pool_id column to the lease4 table.
+ALTER TABLE lease4
+    ADD COLUMN pool_id BIGINT NOT NULL DEFAULT 0;
+
+-- Add pool_id column to the lease6 table.
+ALTER TABLE lease6
+    ADD COLUMN pool_id BIGINT NOT NULL DEFAULT 0;
+
+-- Create v4 lease statistics table
+CREATE TABLE lease4_pool_stat (
+    subnet_id BIGINT NOT NULL,
+    pool_id BIGINT NOT NULL,
+    state INT8 NOT NULL,
+    leases BIGINT,
+    PRIMARY KEY (subnet_id, pool_id, state)
+);
+
+-- Create v6 lease statistics table
+CREATE TABLE lease6_pool_stat (
+    subnet_id BIGINT NOT NULL,
+    pool_id BIGINT NOT NULL,
+    lease_type SMALLINT NOT NULL,
+    state INT8 NOT NULL,
+    leases BIGINT,
+    PRIMARY KEY (subnet_id, pool_id, lease_type, state)
+);
+
+CREATE OR REPLACE FUNCTION lease4_AINS_lease4_pool_stat(IN new_state BIGINT,
+                                                        IN new_subnet_id BIGINT,
+                                                        IN new_pool_id BIGINT)
+RETURNS VOID
+AS $$
+BEGIN
+    IF new_state = 0 OR new_state = 1 THEN
+        -- Update the state count if it exists.
+        UPDATE lease4_pool_stat SET leases = leases + 1
+            WHERE subnet_id = new_subnet_id AND pool_id = new_pool_id
+            AND state = new_state;
+
+        -- Insert the state count record if it does not exist.
+        IF NOT FOUND THEN
+            INSERT INTO lease4_pool_stat
+            VALUES (new_subnet_id, new_pool_id, new_state, 1);
+        END IF;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease4_AUPD_lease4_pool_stat(IN old_state BIGINT,
+                                                        IN old_subnet_id BIGINT,
+                                                        IN old_pool_id BIGINT,
+                                                        IN new_state BIGINT,
+                                                        IN new_subnet_id BIGINT,
+                                                        IN new_pool_id BIGINT)
+RETURNS VOID
+AS $$
+BEGIN
+    IF old_subnet_id != new_subnet_id OR
+       old_pool_id != new_pool_id OR
+       old_state != new_state THEN
+        IF old_state = 0 OR old_state = 1 THEN
+            -- Decrement the old state count if record exists.
+            UPDATE lease4_pool_stat
+                SET leases = GREATEST(leases - 1, 0)
+                WHERE subnet_id = old_subnet_id AND pool_id = old_pool_id
+                AND state = old_state;
+        END IF;
+
+        IF new_state = 0 OR new_state = 1 THEN
+            -- Increment the new state count if record exists.
+            UPDATE lease4_pool_stat SET leases = leases + 1
+                WHERE subnet_id = new_subnet_id AND pool_id = new_pool_id
+                AND state = new_state;
+
+            -- Insert new state record if it does not exist.
+            IF NOT FOUND THEN
+                INSERT INTO lease4_pool_stat
+                VALUES (new_subnet_id, new_pool_id, new_state, 1);
+            END IF;
+        END IF;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease4_ADEL_lease4_pool_stat(IN old_state BIGINT,
+                                                        IN old_subnet_id BIGINT,
+                                                        IN old_pool_id BIGINT)
+RETURNS VOID
+AS $$
+BEGIN
+    IF old_state = 0 OR old_state = 1 THEN
+        -- Decrement the state count if record exists.
+        UPDATE lease4_pool_stat
+            SET leases = GREATEST(leases - 1, 0)
+            WHERE subnet_id = old_subnet_id AND pool_id = old_pool_id
+            AND state = old_state;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_AINS_lease6_pool_stat(IN new_state BIGINT,
+                                                        IN new_subnet_id BIGINT,
+                                                        IN new_pool_id BIGINT,
+                                                        IN new_lease_type SMALLINT)
+RETURNS VOID
+AS $$
+BEGIN
+    IF new_state = 0 OR new_state = 1 THEN
+        -- Update the state count if it exists.
+        UPDATE lease6_pool_stat SET leases = leases + 1
+            WHERE subnet_id = new_subnet_id AND pool_id = new_pool_id
+            AND lease_type = new_lease_type AND state = new_state;
+
+        -- Insert the state count record if it does not exist.
+        IF NOT FOUND THEN
+            INSERT INTO lease6_pool_stat
+            VALUES (new_subnet_id, new_pool_id, new_lease_type, new_state, 1);
+        END IF;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_AUPD_lease6_pool_stat(IN old_state BIGINT,
+                                                        IN old_subnet_id BIGINT,
+                                                        IN old_pool_id BIGINT,
+                                                        IN old_lease_type SMALLINT,
+                                                        IN new_state BIGINT,
+                                                        IN new_subnet_id BIGINT,
+                                                        IN new_pool_id BIGINT,
+                                                        IN new_lease_type SMALLINT)
+RETURNS VOID
+AS $$
+BEGIN
+    IF old_subnet_id != new_subnet_id OR
+       old_pool_id != new_pool_id OR
+       old_lease_type != new_lease_type OR
+       old_state != new_state THEN
+        IF old_state = 0 OR old_state = 1 THEN
+            -- Decrement the old state count if record exists.
+            UPDATE lease6_pool_stat
+                SET leases = GREATEST(leases - 1, 0)
+                WHERE subnet_id = old_subnet_id AND pool_id = old_pool_id
+                AND lease_type = old_lease_type AND state = old_state;
+        END IF;
+
+        IF new_state = 0 OR new_state = 1 THEN
+            -- Increment the new state count if record exists
+            UPDATE lease6_pool_stat SET leases = leases + 1
+                WHERE subnet_id = new_subnet_id AND pool_id = new_pool_id
+                AND lease_type = new_lease_type AND state = new_state;
+
+            -- Insert new state record if it does not exist
+            IF NOT FOUND THEN
+                INSERT INTO lease6_pool_stat
+                VALUES (new_subnet_id, new_pool_id, new_lease_type, new_state, 1);
+            END IF;
+        END IF;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_ADEL_lease6_pool_stat(IN old_state BIGINT,
+                                                        IN old_subnet_id BIGINT,
+                                                        IN old_pool_id BIGINT,
+                                                        IN old_lease_type SMALLINT)
+RETURNS VOID
+AS $$
+BEGIN
+    IF old_state = 0 OR old_state = 1 THEN
+        -- Decrement the state count if record exists
+        UPDATE lease6_pool_stat
+            SET leases = GREATEST(leases - 1, 0)
+            WHERE subnet_id = old_subnet_id AND pool_id = old_pool_id
+            AND lease_type = old_lease_type AND state = old_state;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION func_lease4_AINS()
+RETURNS trigger AS $lease4_AINS$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease4_AINS_lease4_stat_by_client_class(NEW.state, NEW.user_context);
+    END IF;
+    PERFORM lease4_AINS_lease4_stat(NEW.state, NEW.subnet_id);
+    PERFORM lease4_AINS_lease4_pool_stat(NEW.state, NEW.subnet_id, NEW.pool_id);
+    RETURN NULL;
+END;
+$lease4_AINS$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION func_lease4_AUPD()
+RETURNS trigger AS $lease4_AUPD$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease4_AUPD_lease4_stat_by_client_class(OLD.state, OLD.user_context, NEW.state, NEW.user_context);
+    END IF;
+    PERFORM lease4_AUPD_lease4_stat(OLD.state, OLD.subnet_id, NEW.state, NEW.subnet_id);
+    PERFORM lease4_AUPD_lease4_pool_stat(OLD.state, OLD.subnet_id, OLD.pool_id, NEW.state, NEW.subnet_id, NEW.pool_id);
+    RETURN NULL;
+END;
+$lease4_AUPD$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION func_lease4_ADEL()
+RETURNS trigger AS $lease4_ADEL$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease4_ADEL_lease4_stat_by_client_class(OLD.state, OLD.user_context);
+    END IF;
+    PERFORM lease4_ADEL_lease4_stat(OLD.state, OLD.subnet_id);
+    PERFORM lease4_ADEL_lease4_pool_stat(OLD.state, OLD.subnet_id, OLD.pool_id);
+    RETURN NULL;
+END;
+$lease4_ADEL$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION func_lease6_AINS()
+RETURNS trigger AS $lease6_AINS$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease6_AINS_lease6_stat_by_client_class(NEW.state, NEW.user_context, NEW.lease_type);
+    END IF;
+    PERFORM lease6_AINS_lease6_stat(NEW.state, NEW.subnet_id, NEW.lease_type);
+    PERFORM lease6_AINS_lease6_pool_stat(NEW.state, NEW.subnet_id, NEW.pool_id, NEW.lease_type);
+    RETURN NULL;
+END;
+$lease6_AINS$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION func_lease6_AUPD()
+RETURNS trigger AS $lease6_AUPD$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease6_AUPD_lease6_stat_by_client_class(OLD.state, OLD.user_context, OLD.lease_type, NEW.state, NEW.user_context, NEW.lease_type);
+    END IF;
+    PERFORM lease6_AUPD_lease6_stat(OLD.state, OLD.subnet_id, OLD.lease_type, NEW.state, NEW.subnet_id, NEW.lease_type);
+    PERFORM lease6_AUPD_lease6_pool_stat(OLD.state, OLD.subnet_id, OLD.pool_id, OLD.lease_type, NEW.state, NEW.subnet_id, NEW.pool_id, NEW.lease_type);
+    RETURN NULL;
+END;
+$lease6_AUPD$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION func_lease6_ADEL()
+RETURNS trigger AS $lease6_ADEL$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease6_ADEL_lease6_stat_by_client_class(OLD.state, OLD.user_context, OLD.lease_type);
+    END IF;
+    PERFORM lease6_ADEL_lease6_stat(OLD.state, OLD.subnet_id, OLD.lease_type);
+    PERFORM lease6_ADEL_lease6_pool_stat(OLD.state, OLD.subnet_id, OLD.pool_id, OLD.lease_type);
+    RETURN NULL;
+END;
+$lease6_ADEL$ LANGUAGE plpgsql;
+
+DROP FUNCTION IF EXISTS lease4DumpHeader();
+CREATE OR REPLACE FUNCTION lease4DumpHeader()
+RETURNS text AS $$
+    select cast('address,hwaddr,client_id,valid_lifetime,expire,subnet_id,fqdn_fwd,fqdn_rev,hostname,state,user_context,pool_id' as text) as result;
+$$ LANGUAGE SQL;
+
+-- Adding support for pool ID in function to output a memfile-ready CSV file.
+-- Some columns that are SMALLINT in the lease4 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+DROP FUNCTION IF EXISTS lease4DumpData();
+CREATE OR REPLACE FUNCTION lease4DumpData()
+RETURNS TABLE (
+    address INET,
+    hwaddr VARCHAR,
+    client_id VARCHAR,
+    valid_lifetime BIGINT,
+    expire BIGINT,
+    subnet_id BIGINT,
+    fqdn_fwd INT,
+    fqdn_rev INT,
+    hostname VARCHAR,
+    state INT8,
+    user_context VARCHAR,
+    pool_id BIGINT
+) AS $$
+    SELECT
+        ('0.0.0.0'::inet + address),
+        colonSeparatedHex(encode(hwaddr, 'hex')),
+        colonSeparatedHex(encode(client_id, 'hex')),
+        valid_lifetime,
+        extract(epoch from expire)::bigint,
+        subnet_id,
+        fqdn_fwd::int,
+        fqdn_rev::int,
+        replace(hostname, ',', '&#x2c'),
+        state,
+        replace(user_context, ',', '&#x2c'),
+        pool_id
+    FROM lease4
+    ORDER BY address;
+$$ LANGUAGE SQL;
+
+DROP FUNCTION IF EXISTS lease6DumpHeader();
+CREATE OR REPLACE FUNCTION lease6DumpHeader()
+RETURNS TEXT AS $$
+    SELECT CAST('address,duid,valid_lifetime,expire,subnet_id,pref_lifetime,lease_type,iaid,prefix_len,fqdn_fwd,fqdn_rev,hostname,hwaddr,state,user_context,hwtype,hwaddr_source,pool_id' AS TEXT) AS result;
+$$ LANGUAGE SQL;
+
+-- Adding support for pool ID in function to output a memfile-ready CSV file.
+-- Some columns that are SMALLINT in the lease6 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+DROP FUNCTION IF EXISTS lease6DumpData();
+CREATE OR REPLACE FUNCTION lease6DumpData()
+RETURNS TABLE (
+    address VARCHAR,
+    duid VARCHAR,
+    valid_lifetime BIGINT,
+    expire BIGINT,
+    subnet_id BIGINT,
+    pref_lifetime BIGINT,
+    lease_type SMALLINT,
+    iaid INT,
+    prefix_len SMALLINT,
+    fqdn_fwd INT,
+    fqdn_rev INT,
+    hostname VARCHAR,
+    hwaddr VARCHAR,
+    state INT8,
+    user_context VARCHAR,
+    hwtype SMALLINT,
+    hwaddr_source SMALLINT,
+    pool_id BIGINT
+) AS $$
+    SELECT
+        address,
+        colonSeparatedHex(encode(duid, 'hex')),
+        valid_lifetime,
+        extract(epoch from expire)::bigint,
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd::int,
+        fqdn_rev::int,
+        replace(hostname, ',', '&#x2c'),
+        colonSeparatedHex(encode(hwaddr, 'hex')),
+        state,
+        replace(user_context, ',', '&#x2c'),
+        hwtype,
+        hwaddr_source,
+        pool_id
+    FROM lease6
+    ORDER BY address;
+$$ LANGUAGE SQL;
+
+-- Adding support for pool id in function that inserts a v4 lease from memfile data.
+-- Some columns that are SMALLINT in the lease4 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+CREATE OR REPLACE FUNCTION lease4Upload(
+    IN address VARCHAR,
+    IN hwaddr VARCHAR,
+    IN client_id VARCHAR,
+    IN valid_lifetime BIGINT,
+    IN expire BIGINT,
+    IN subnet_id BIGINT,
+    IN fqdn_fwd INT,
+    IN fqdn_rev INT,
+    IN hostname VARCHAR,
+    IN state INT8,
+    IN user_context VARCHAR,
+    IN pool_id BIGINT
+) RETURNS VOID AS $$
+BEGIN
+    INSERT INTO lease4 (
+        address,
+        hwaddr,
+        client_id,
+        valid_lifetime,
+        expire,
+        subnet_id,
+        fqdn_fwd,
+        fqdn_rev,
+        hostname,
+        state,
+        user_context,
+        pool_id
+    ) VALUES (
+        address::inet - '0.0.0.0'::inet,
+        decode(replace(hwaddr, ':', ''), 'hex'),
+        decode(replace(client_id, ':', ''), 'hex'),
+        valid_lifetime,
+        to_timestamp(expire),
+        subnet_id,
+        fqdn_fwd::int::boolean,
+        fqdn_rev::int::boolean,
+        replace(hostname, '&#x2c', ','),
+        state,
+        replace(user_context, '&#x2c', ','),
+        pool_id
+    );
+END
+$$ LANGUAGE plpgsql;
+
+-- Adding support for pool id in function that inserts a v6 lease from memfile data.
+-- Some columns that are SMALLINT in the lease6 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+CREATE OR REPLACE FUNCTION lease6Upload(
+    IN address VARCHAR,
+    IN duid VARCHAR,
+    IN valid_lifetime BIGINT,
+    IN expire BIGINT,
+    IN subnet_id BIGINT,
+    IN pref_lifetime BIGINT,
+    IN lease_type INT,
+    IN iaid INT,
+    IN prefix_len INT,
+    IN fqdn_fwd INT,
+    IN fqdn_rev INT,
+    IN hostname VARCHAR,
+    IN hwaddr VARCHAR,
+    IN state INT8,
+    IN user_context VARCHAR,
+    IN hwtype INT,
+    IN hwaddr_source INT,
+    IN pool_id BIGINT
+) RETURNS VOID AS $$
+BEGIN
+    INSERT INTO lease6 (
+        address,
+        duid,
+        valid_lifetime,
+        expire,
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd,
+        fqdn_rev,
+        hostname,
+        hwaddr,
+        state,
+        user_context,
+        hwtype,
+        hwaddr_source,
+        pool_id
+    ) VALUES (
+        address,
+        decode(replace(duid, ':', ''), 'hex'),
+        valid_lifetime,
+        to_timestamp(expire),
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd::int::boolean,
+        fqdn_rev::int::boolean,
+        replace(hostname, '&#x2c', ','),
+        decode(replace(hwaddr, ':', ''), 'hex'),
+        state,
+        replace(user_context, '&#x2c', ','),
+        hwtype,
+        hwaddr_source,
+        pool_id
+    );
+END
+$$ LANGUAGE plpgsql;
+
+INSERT INTO lease4_pool_stat (subnet_id, pool_id, state, leases)
+    SELECT subnet_id, pool_id, state, count(*) FROM lease4
+    WHERE state = 0 OR state = 1 GROUP BY subnet_id, pool_id, state;
+
+INSERT INTO lease6_pool_stat (subnet_id, pool_id, lease_type, state, leases)
+    SELECT subnet_id, pool_id, lease_type, state, count(*) FROM lease6
+    WHERE state = 0 OR state = 1 GROUP BY subnet_id, pool_id, lease_type, state;
+
+-- Add the binary version of the IPv6 address for v6 BLQ prefix filter.
+ALTER TABLE lease6
+    ADD COLUMN binaddr BYTEA DEFAULT NULL;
+CREATE INDEX lease6_by_binaddr ON lease6 (binaddr ASC);
+
+-- Create table for v6 BLQ by-relay-id.
+CREATE TABLE lease6_relay_id (
+    extended_info_id SERIAL PRIMARY KEY NOT NULL,
+    relay_id BYTEA NOT NULL,
+    lease_addr BYTEA NOT NULL);
+CREATE INDEX lease6_relay_id_by_id ON lease6_relay_id (relay_id, lease_addr ASC);
+CREATE INDEX lease6_relay_id_by_address ON lease6_relay_id (lease_addr);
+
+-- Create table for v6 BLQ by-remote-id.
+CREATE TABLE lease6_remote_id (
+    extended_info_id SERIAL PRIMARY KEY NOT NULL,
+    remote_id BYTEA NOT NULL,
+    lease_addr BYTEA NOT NULL);
+CREATE INDEX lease6_remote_id_by_id ON lease6_remote_id (remote_id, lease_addr ASC);
+CREATE INDEX lease6_remote_id_by_address ON lease6_remote_id (lease_addr);
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '17', minor = '0';
+
+-- This line concludes the schema upgrade to version 17.0.
+
+-- This line starts the schema upgrade to version 18.0.
+
+-- Drop binaddr index and column from lease6.
+DROP INDEX lease6_by_binaddr;
+ALTER TABLE lease6
+    DROP COLUMN binaddr;
+
+-- Change lease6:address to INET.
+ALTER TABLE lease6 ALTER COLUMN address TYPE INET USING address::INET;
+
+-- Change ipv6_reservations:address to INET.
+ALTER TABLE ipv6_reservations ALTER COLUMN address TYPE INET USING address::INET;
+
+-- Invoke HOST() on address now that address type is inet
+CREATE OR REPLACE FUNCTION lease6DumpData()
+RETURNS TABLE (
+    address VARCHAR,
+    duid VARCHAR,
+    valid_lifetime BIGINT,
+    expire BIGINT,
+    subnet_id BIGINT,
+    pref_lifetime BIGINT,
+    lease_type SMALLINT,
+    iaid INT,
+    prefix_len SMALLINT,
+    fqdn_fwd INT,
+    fqdn_rev INT,
+    hostname VARCHAR,
+    hwaddr VARCHAR,
+    state INT8,
+    user_context VARCHAR,
+    hwtype SMALLINT,
+    hwaddr_source SMALLINT,
+    pool_id BIGINT
+) AS $$
+    SELECT
+        HOST(address),
+        colonSeparatedHex(encode(duid, 'hex')),
+        valid_lifetime,
+        extract(epoch from expire)::bigint,
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd::int,
+        fqdn_rev::int,
+        replace(hostname, ',', '&#x2c'),
+        colonSeparatedHex(encode(hwaddr, 'hex')),
+        state,
+        replace(user_context, ',', '&#x2c'),
+        hwtype,
+        hwaddr_source,
+        pool_id
+    FROM lease6
+    ORDER BY address;
+$$ LANGUAGE SQL;
+
+-- Invoke HOST() on address now that address type is inet
+CREATE OR REPLACE FUNCTION lease6Upload(
+    IN address VARCHAR,
+    IN duid VARCHAR,
+    IN valid_lifetime BIGINT,
+    IN expire BIGINT,
+    IN subnet_id BIGINT,
+    IN pref_lifetime BIGINT,
+    IN lease_type INT,
+    IN iaid INT,
+    IN prefix_len INT,
+    IN fqdn_fwd INT,
+    IN fqdn_rev INT,
+    IN hostname VARCHAR,
+    IN hwaddr VARCHAR,
+    IN state INT8,
+    IN user_context VARCHAR,
+    IN hwtype INT,
+    IN hwaddr_source INT,
+    IN pool_id BIGINT
+) RETURNS VOID AS $$
+BEGIN
+    INSERT INTO lease6 (
+        address,
+        duid,
+        valid_lifetime,
+        expire,
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd,
+        fqdn_rev,
+        hostname,
+        hwaddr,
+        state,
+        user_context,
+        hwtype,
+        hwaddr_source,
+        pool_id
+    ) VALUES (
+        cast(address as inet),
+        decode(replace(duid, ':', ''), 'hex'),
+        valid_lifetime,
+        to_timestamp(expire),
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd::int::boolean,
+        fqdn_rev::int::boolean,
+        replace(hostname, '&#x2c', ','),
+        decode(replace(hwaddr, ':', ''), 'hex'),
+        state,
+        replace(user_context, '&#x2c', ','),
+        hwtype,
+        hwaddr_source,
+        pool_id
+    );
+END
+$$ LANGUAGE plpgsql;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '18', minor = '0';
+
+-- This line concludes the schema upgrade to version 18.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+-- Notes:
+
+-- Indexes
+-- =======
+-- It is likely that additional indexes will be needed.  However, the
+-- increase in lookup performance from these will come at the expense
+-- of a decrease in performance during insert operations due to the need
+-- to update the indexes.  For this reason, the need for additional indexes
+-- will be determined by experiment during performance tests.
+
+-- The most likely additional indexes will cover the following columns:
+
+-- hwaddr and client_id
+-- For lease stability: if a client requests a new lease, try to find an
+-- existing or recently expired lease for it so that it can keep using the
+-- same IP address.
+
+-- Field Sizes
+-- ===========
+-- If any of the VARxxx field sizes are altered, the lengths in the PgSQL
+-- backend source file (pgsql_lease_mgr.cc) must be correspondingly changed.
+
+-- Portability
+-- ===========
+-- Some columns contain binary data so are stored as BYTEA instead of
+-- VARCHAR.  This may be non-portable between databases: in this case, the
+-- definition should be changed to VARCHAR.
diff --git a/src/share/database/scripts/pgsql/dhcpdb_drop.pgsql b/src/share/database/scripts/pgsql/dhcpdb_drop.pgsql
new file mode 100644
index 0000000..044d9aa
--- /dev/null
+++ b/src/share/database/scripts/pgsql/dhcpdb_drop.pgsql
@@ -0,0 +1,249 @@
+-- Copyright (C) 2016-2023 Internet Systems Consortium.
+
+-- This Source Code Form is subject to the terms of the Mozilla Public
+-- License, v. 2.0. If a copy of the MPL was not distributed with this
+-- file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DROP TABLE IF EXISTS lease4 CASCADE;
+DROP TABLE IF EXISTS lease6 CASCADE;
+DROP TABLE IF EXISTS lease6_types CASCADE;
+DROP TABLE IF EXISTS schema_version CASCADE;
+DROP TABLE IF EXISTS lease_state CASCADE;
+DROP TABLE IF EXISTS dhcp4_options CASCADE;
+DROP TABLE IF EXISTS dhcp6_options CASCADE;
+DROP TABLE IF EXISTS ipv6_reservations CASCADE;
+DROP TABLE IF EXISTS lease_hwaddr_source CASCADE;
+DROP TABLE IF EXISTS host_identifier_type CASCADE;
+DROP TABLE IF EXISTS dhcp_option_scope CASCADE;
+DROP TABLE IF EXISTS hosts CASCADE;
+DROP FUNCTION IF EXISTS lease4DumpHeader();
+DROP FUNCTION IF EXISTS lease4DumpData();
+DROP FUNCTION IF EXISTS lease6DumpHeader();
+DROP FUNCTION IF EXISTS lease6DumpData();
+DROP TABLE IF EXISTS lease4_stat CASCADE;
+DROP TABLE IF EXISTS lease4_pool_stat CASCADE;
+DROP FUNCTION IF EXISTS proc_stat_lease4_insert ();
+DROP FUNCTION IF EXISTS proc_stat_lease4_update ();
+DROP FUNCTION IF EXISTS proc_stat_lease4_delete ();
+DROP TABLE IF EXISTS lease6_stat CASCADE;
+DROP TABLE IF EXISTS lease6_pool_stat CASCADE;
+DROP FUNCTION IF EXISTS proc_stat_lease6_insert ();
+DROP FUNCTION IF EXISTS proc_stat_lease6_update ();
+DROP FUNCTION IF EXISTS proc_stat_lease6_delete ();
+DROP TABLE IF EXISTS logs CASCADE;
+
+-- config backend procedures for DHCPv6
+DROP FUNCTION IF EXISTS createAuditRevisionDHCP6(audit_ts TIMESTAMP WITH TIME ZONE, server_tag VARCHAR(64),
+                                                 audit_log_message TEXT, cascade_transaction BOOLEAN);
+DROP FUNCTION IF EXISTS createAuditEntryDHCP6(object_type_val VARCHAR(256), object_id_val BIGINT,
+                                              modification_type_val VARCHAR(32));
+DROP FUNCTION IF EXISTS createOptionAuditDHCP6(modification_type VARCHAR, scope_id SMALLINT,
+                                               option_id INT, subnet_id BIGINT, host_id INT,
+                                               network_name VARCHAR, pool_id BIGINT, pd_pool_id BIGINT,
+                                               modification_ts TIMESTAMP WITH TIME ZONE);
+DROP FUNCTION IF EXISTS createOptionAuditDHCP6(modification_type VARCHAR, scope_id SMALLINT,
+                                               option_id INT, p_subnet_id BIGINT, host_id INT,
+                                               network_name VARCHAR, pool_id BIGINT, pd_pool_id BIGINT,
+                                               p_modification_ts TIMESTAMP WITH TIME ZONE);
+DROP FUNCTION IF EXISTS setClientClass6Order(id BIGINT, follow_class_name VARCHAR(128),
+                                             old_follow_class_name VARCHAR(128));
+DROP FUNCTION IF EXISTS checkDHCPv6ClientClassDependency(class_id BIGINT, dependency_id BIGINT);
+DROP FUNCTION IF EXISTS updateDHCPv6ClientClassKnownDependency(client_class_id BIGINT,
+                                                               dependency_id BIGINT);
+DROP FUNCTION IF EXISTS checkDHCPv6ClientClassKnownDependencyChange();
+
+-- config backend tables for DHCPv6
+DROP TABLE IF EXISTS dhcp6_audit CASCADE;
+DROP TABLE IF EXISTS dhcp6_option_def_server CASCADE;
+DROP TABLE IF EXISTS dhcp6_option_def CASCADE;
+DROP TABLE IF EXISTS dhcp6_options_server CASCADE;
+DROP TABLE IF EXISTS dhcp6_pool CASCADE;
+DROP TABLE IF EXISTS dhcp6_pd_pool CASCADE;
+DROP TABLE IF EXISTS dhcp6_subnet_server CASCADE;
+DROP TABLE IF EXISTS dhcp6_subnet CASCADE;
+DROP TABLE IF EXISTS dhcp6_shared_network_server CASCADE;
+DROP TABLE IF EXISTS dhcp6_shared_network CASCADE;
+DROP TABLE IF EXISTS dhcp6_global_parameter_server CASCADE;
+DROP TABLE IF EXISTS dhcp6_global_parameter CASCADE;
+DROP TABLE IF EXISTS dhcp6_server CASCADE;
+DROP TABLE IF EXISTS dhcp6_audit_revision CASCADE;
+DROP TABLE IF EXISTS dhcp6_client_class_server CASCADE;
+DROP TABLE IF EXISTS dhcp6_client_class_dependency CASCADE;
+DROP TABLE IF EXISTS dhcp6_client_class_order CASCADE;
+DROP TABLE IF EXISTS dhcp6_client_class CASCADE;
+
+-- drop trigger functions for DHCPv6
+DROP FUNCTION IF EXISTS func_dhcp6_client_class_AINS();
+DROP FUNCTION IF EXISTS func_dhcp6_client_class_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp6_client_class_ADEL();
+DROP FUNCTION IF EXISTS func_dhcp6_client_class_check_dependency_BINS();
+DROP FUNCTION IF EXISTS func_dhcp6_client_class_dependency_AINS();
+DROP FUNCTION IF EXISTS func_dhcp6_pool_BDEL();
+DROP FUNCTION IF EXISTS func_dhcp6_global_parameter_AINS();
+DROP FUNCTION IF EXISTS func_dhcp6_global_parameter_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp6_global_parameter_ADEL();
+DROP FUNCTION IF EXISTS func_dhcp6_subnet_AINS();
+DROP FUNCTION IF EXISTS func_dhcp6_subnet_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp6_shared_network_AINS();
+DROP FUNCTION IF EXISTS func_dhcp6_shared_network_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp6_shared_network_ADEL();
+DROP FUNCTION IF EXISTS func_dhcp6_option_def_AINS();
+DROP FUNCTION IF EXISTS func_dhcp6_option_def_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp6_option_def_ADEL();
+DROP FUNCTION IF EXISTS func_dhcp6_options_AINS();
+DROP FUNCTION IF EXISTS func_dhcp6_options_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp6_options_ADEL();
+DROP FUNCTION IF EXISTS func_dhcp6_server_AINS();
+DROP FUNCTION IF EXISTS func_dhcp6_server_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp6_server_ADEL();
+DROP FUNCTION IF EXISTS func_dhcp6_shared_network_BDEL();
+DROP FUNCTION IF EXISTS func_dhcp6_subnet_BDEL();
+DROP FUNCTION IF EXISTS func_dhcp6_pd_pool_BDEL();
+
+-- config backend procedures for DHCPv4
+DROP FUNCTION IF EXISTS createAuditRevisionDHCP4(audit_ts TIMESTAMP WITH TIME ZONE, server_tag VARCHAR(64),
+                                                 audit_log_message TEXT, cascade_transaction BOOLEAN);
+DROP FUNCTION IF EXISTS createAuditEntryDHCP4(object_type_val VARCHAR(256), object_id_val BIGINT,
+                                              modification_type_val VARCHAR(32));
+DROP FUNCTION IF EXISTS createOptionAuditDHCP4(modification_type VARCHAR, scope_id SMALLINT,
+                                               option_id INT, subnet_id BIGINT, host_id INT,
+                                               network_name VARCHAR, pool_id BIGINT,
+                                               modification_ts TIMESTAMP WITH TIME ZONE);
+DROP FUNCTION IF EXISTS setClientClass4Order(id BIGINT, follow_class_name VARCHAR(128),
+                                             old_follow_class_name VARCHAR(128));
+DROP FUNCTION IF EXISTS checkDHCPv4ClientClassDependency(class_id BIGINT, dependency_id BIGINT);
+DROP FUNCTION IF EXISTS updateDHCPv4ClientClassKnownDependency(client_class_id BIGINT,
+                                                               dependency_id BIGINT);
+DROP FUNCTION IF EXISTS checkDHCPv4ClientClassKnownDependencyChange();
+
+-- config backend tables for DHCPv4
+DROP TABLE IF EXISTS dhcp4_audit CASCADE;
+DROP TABLE IF EXISTS dhcp4_option_def_server CASCADE;
+DROP TABLE IF EXISTS dhcp4_option_def CASCADE;
+DROP TABLE IF EXISTS dhcp4_options_server CASCADE;
+DROP TABLE IF EXISTS dhcp4_pool CASCADE;
+DROP TABLE IF EXISTS dhcp4_pd_pool CASCADE;
+DROP TABLE IF EXISTS dhcp4_subnet_server CASCADE;
+DROP TABLE IF EXISTS dhcp4_subnet CASCADE;
+DROP TABLE IF EXISTS dhcp4_shared_network_server CASCADE;
+DROP TABLE IF EXISTS dhcp4_shared_network CASCADE;
+DROP TABLE IF EXISTS dhcp4_global_parameter_server CASCADE;
+DROP TABLE IF EXISTS dhcp4_global_parameter CASCADE;
+DROP TABLE IF EXISTS dhcp4_server CASCADE;
+DROP TABLE IF EXISTS dhcp4_audit_revision CASCADE;
+DROP TABLE IF EXISTS dhcp4_client_class_server CASCADE;
+DROP TABLE IF EXISTS dhcp4_client_class_dependency CASCADE;
+DROP TABLE IF EXISTS dhcp4_client_class_order CASCADE;
+DROP TABLE IF EXISTS dhcp4_client_class CASCADE;
+
+-- drop trigger functions for DHCPv4
+DROP FUNCTION IF EXISTS func_dhcp4_client_class_AINS();
+DROP FUNCTION IF EXISTS func_dhcp4_client_class_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp4_client_class_ADEL();
+DROP FUNCTION IF EXISTS func_dhcp4_client_class_check_dependency_BINS();
+DROP FUNCTION IF EXISTS func_dhcp4_client_class_dependency_AINS();
+DROP FUNCTION IF EXISTS func_dhcp4_pool_BDEL();
+DROP FUNCTION IF EXISTS func_dhcp4_global_parameter_AINS();
+DROP FUNCTION IF EXISTS func_dhcp4_global_parameter_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp4_global_parameter_ADEL();
+DROP FUNCTION IF EXISTS func_dhcp4_subnet_AINS();
+DROP FUNCTION IF EXISTS func_dhcp4_subnet_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp4_shared_network_AINS();
+DROP FUNCTION IF EXISTS func_dhcp4_shared_network_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp4_shared_network_ADEL();
+DROP FUNCTION IF EXISTS func_dhcp4_option_def_AINS();
+DROP FUNCTION IF EXISTS func_dhcp4_option_def_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp4_option_def_ADEL();
+DROP FUNCTION IF EXISTS func_dhcp4_options_AINS();
+DROP FUNCTION IF EXISTS func_dhcp4_options_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp4_options_ADEL();
+DROP FUNCTION IF EXISTS func_dhcp4_server_AINS();
+DROP FUNCTION IF EXISTS func_dhcp4_server_AUPD();
+DROP FUNCTION IF EXISTS func_dhcp4_server_ADEL();
+DROP FUNCTION IF EXISTS func_dhcp4_shared_network_BDEL();
+DROP FUNCTION IF EXISTS func_dhcp4_subnet_BDEL();
+
+-- common tables for config backend
+DROP TABLE IF EXISTS modification CASCADE;
+DROP TABLE IF EXISTS parameter_data_type CASCADE;
+DROP TABLE IF EXISTS ddns_replace_client_name_types CASCADE;
+DROP FUNCTION IF EXISTS modification_ts_update();
+DROP FUNCTION IF EXISTS get_session_boolean(name text);
+DROP FUNCTION IF EXISTS get_session_big_int(name text);
+DROP FUNCTION IF EXISTS get_session_value(name text);
+DROP FUNCTION IF EXISTS set_session_value(name text, value TEXT);
+DROP FUNCTION IF EXISTS set_session_value(name text, value BIGINT);
+DROP FUNCTION IF EXISTS set_session_value(name text, value BOOLEAN);
+
+DROP FUNCTION IF EXISTS lease4Upload(address VARCHAR, hwaddr VARCHAR,
+    client_id VARCHAR, valid_lifetime BIGINT, expire BIGINT, subnet_id BIGINT,
+    fqdn_fwd INT, fqdn_rev INT, hostname VARCHAR, state INT8,
+    user_context VARCHAR);
+DROP FUNCTION IF EXISTS lease6Upload(address VARCHAR, duid VARCHAR,
+    valid_lifetime BIGINT, expire BIGINT, subnet_id BIGINT,
+    pref_lifetime BIGINT, lease_type INT, iaid INT, prefix_len INT,
+    fqdn_fwd INT, fqdn_rev INT, hostname VARCHAR, hwaddr VARCHAR,
+    state INT8, user_context VARCHAR, hwtype INT, hwaddr_source INT);
+DROP FUNCTION IF EXISTS colonSeparatedHex(TEXT);
+
+DROP FUNCTION IF EXISTS gmt_epoch(input_time TIMESTAMP WITH TIME ZONE);
+
+-- lease limiting tables and functions
+DROP TABLE IF EXISTS lease4_stat_by_client_class;
+DROP TABLE IF EXISTS lease6_stat_by_client_class;
+DROP FUNCTION IF EXISTS lease4_AINS_lease4_stat(new_state BIGINT,
+                                                new_subnet_id BIGINT);
+DROP FUNCTION IF EXISTS lease4_AUPD_lease4_stat(old_state BIGINT,
+        old_subnet_id BIGINT, new_state BIGINT, new_subnet_id BIGINT);
+DROP FUNCTION IF EXISTS lease4_ADEL_lease4_stat(old_state BIGINT,
+                                                old_subnet_id BIGINT);
+DROP FUNCTION IF EXISTS lease6_AINS_lease6_stat(new_state BIGINT,
+        new_subnet_id BIGINT, new_lease_type SMALLINT);
+DROP FUNCTION IF EXISTS lease6_AUPD_lease6_stat(old_state BIGINT,
+        old_subnet_id BIGINT, old_lease_type SMALLINT, new_state BIGINT,
+        new_subnet_id BIGINT, new_lease_type SMALLINT);
+DROP FUNCTION IF EXISTS lease6_ADEL_lease6_stat(old_state BIGINT,
+        old_subnet_id BIGINT, old_lease_type SMALLINT);
+DROP FUNCTION IF EXISTS lease4_AINS_lease4_pool_stat(new_state BIGINT,
+        new_subnet_id BIGINT, new_pool_id BIGINT);
+DROP FUNCTION IF EXISTS lease4_AUPD_lease4_pool_stat(old_state BIGINT,
+        old_subnet_id BIGINT, old_pool_id BIGINT, new_state BIGINT,
+        new_subnet_id BIGINT, new_pool_id BIGINT);
+DROP FUNCTION IF EXISTS lease4_ADEL_lease4_pool_stat(old_state BIGINT,
+        old_subnet_id BIGINT, old_pool_id BIGINT);
+DROP FUNCTION IF EXISTS lease6_AINS_lease6_pool_stat(new_state BIGINT,
+        new_subnet_id BIGINT, new_pool_id BIGINT, new_lease_type SMALLINT);
+DROP FUNCTION IF EXISTS lease6_AUPD_lease6_pool_stat(old_state BIGINT,
+        old_subnet_id BIGINT, old_pool_id BIGINT, old_lease_type SMALLINT,
+        new_state BIGINT, new_subnet_id BIGINT, new_pool_id BIGINT,
+        new_lease_type SMALLINT);
+DROP FUNCTION IF EXISTS lease6_ADEL_lease6_pool_stat(old_state BIGINT,
+        old_subnet_id BIGINT, old_pool_id BIGINT, old_lease_type SMALLINT);
+DROP FUNCTION IF EXISTS lease4_AINS_lease4_stat_by_client_class(
+        new_state BIGINT, new_user_context TEXT);
+DROP FUNCTION IF EXISTS lease4_AUPD_lease4_stat_by_client_class(
+        old_state BIGINT, old_user_context TEXT,
+        new_state BIGINT, new_user_context TEXT);
+DROP FUNCTION IF EXISTS lease4_ADEL_lease4_stat_by_client_class(
+        old_state BIGINT, old_user_context TEXT);
+DROP FUNCTION IF EXISTS lease6_AINS_lease6_stat_by_client_class(
+        new_state BIGINT, new_user_context TEXT, new_lease_type SMALLINT);
+DROP FUNCTION IF EXISTS lease6_AUPD_lease6_stat_by_client_class(
+        old_state BIGINT, old_user_context TEXT, old_lease_type SMALLINT,
+        new_state BIGINT, new_user_context TEXT, new_lease_type SMALLINT);
+DROP FUNCTION IF EXISTS lease6_ADEL_lease6_stat_by_client_class(
+        old_state BIGINT, old_user_context TEXT, old_lease_type SMALLINT);
+DROP FUNCTION IF EXISTS func_lease4_AINS();
+DROP FUNCTION IF EXISTS func_lease4_AUPD();
+DROP FUNCTION IF EXISTS func_lease4_ADEL();
+DROP FUNCTION IF EXISTS func_lease6_AINS();
+DROP FUNCTION IF EXISTS func_lease6_AUPD();
+DROP FUNCTION IF EXISTS func_lease6_ADEL();
+DROP FUNCTION IF EXISTS checkLease4Limits(user_context TEXT);
+DROP FUNCTION IF EXISTS checkLease6Limits(user_context TEXT);
+DROP FUNCTION IF EXISTS isJsonSupported();
+DROP FUNCTION IF EXISTS json_cast(json_candidate TEXT);
+
+-- v6 BLQ cross-tables
+DROP TABLE IF EXISTS lease6_relay_id;
+DROP TABLE IF EXISTS lease6_remote_id;
diff --git a/src/share/database/scripts/pgsql/upgrade_001.0_to_002.0.sh.in b/src/share/database/scripts/pgsql/upgrade_001.0_to_002.0.sh.in
new file mode 100644
index 0000000..2900985
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_001.0_to_002.0.sh.in
@@ -0,0 +1,181 @@
+#!/bin/sh
+
+# Copyright (C) 2016-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "1.0" ]; then
+    printf 'This script upgrades 1.0 to 2.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+
+-- This line starts the schema upgrade to version 2.0.
+
+-- Add state column to the lease4 table.
+ALTER TABLE lease4
+    ADD COLUMN state INT8 DEFAULT 0;
+
+-- Add state column to the lease6 table.
+ALTER TABLE lease6
+    ADD COLUMN state INT8 DEFAULT 0;
+
+-- Create indexes for querying leases in a given state and segregated
+-- by the expiration time. One of the applications is to retrieve all
+-- expired leases. However, these indexes can be also used to retrieve
+-- leases in a given state regardless of the expiration time.
+CREATE INDEX lease4_by_state_expire ON lease4 (state ASC, expire ASC);
+CREATE INDEX lease6_by_state_expire ON lease6 (state ASC, expire ASC);
+
+-- Create table holding mapping of the lease states to their names.
+-- This is not used in queries from the DHCP server but rather in
+-- direct queries from the lease database management tools.
+CREATE TABLE lease_state (
+    state INT8 PRIMARY KEY NOT NULL,
+    name VARCHAR(64) NOT NULL);
+
+-- Insert currently defined state names.
+START TRANSACTION;
+INSERT INTO lease_state VALUES (0, 'default');
+INSERT INTO lease_state VALUES (1, 'declined');
+INSERT INTO lease_state VALUES (2, 'expired-reclaimed');
+COMMIT;
+
+-- Add a constraint that any state value added to the lease4 must
+-- map to a value in the lease_state table.
+ALTER TABLE lease4
+    ADD CONSTRAINT fk_lease4_state FOREIGN KEY (state)
+    REFERENCES lease_state (state);
+
+-- Add a constraint that any state value added to the lease6 must
+-- map to a value in the lease_state table.
+ALTER TABLE lease6
+    ADD CONSTRAINT fk_lease6_state FOREIGN KEY (state)
+    REFERENCES lease_state (state);
+
+-- Add a constraint that lease type in the lease6 table must map
+-- to a lease type defined in the lease6_types table.
+ALTER TABLE lease6
+    ADD CONSTRAINT fk_lease6_type FOREIGN KEY (lease_type)
+    REFERENCES lease6_types (lease_type);
+
+--
+--  FUNCTION that returns a result set containing the column names for lease4 dumps
+DROP FUNCTION IF EXISTS lease4DumpHeader();
+CREATE FUNCTION lease4DumpHeader() RETURNS text AS  \$\$
+    select cast('address,hwaddr,client_id,valid_lifetime,expire,subnet_id,fqdn_fwd,fqdn_rev,hostname,state' as text) as result;
+\$\$ LANGUAGE SQL;
+--
+
+--
+--  FUNCTION that returns a result set containing the data for lease4 dumps
+DROP FUNCTION IF EXISTS lease4DumpData();
+CREATE FUNCTION lease4DumpData() RETURNS
+    table (address inet,
+           hwaddr text,
+           client_id text,
+           valid_lifetime bigint,
+           expire timestamp with time zone,
+           subnet_id bigint,
+           fqdn_fwd int,
+           fqdn_rev int,
+           hostname text,
+           state text
+    ) as \$\$
+    SELECT ('0.0.0.0'::inet + l.address),
+            encode(l.hwaddr,'hex'),
+            encode(l.client_id,'hex'),
+            l.valid_lifetime,
+            l.expire,
+            l.subnet_id,
+            l.fqdn_fwd::int,
+            l.fqdn_rev::int,
+            l.hostname,
+            s.name
+    FROM lease4 l
+         left outer join lease_state s on (l.state = s.state);
+\$\$ LANGUAGE SQL;
+--
+
+--
+--  FUNCTION that returns a result set containing the column names for lease6 dumps
+DROP FUNCTION IF EXISTS lease6DumpHeader();
+CREATE FUNCTION lease6DumpHeader() RETURNS text AS  \$\$
+    select cast('address,duid,valid_lifetime,expire,subnet_id,pref_lifetime,lease_type,iaid,prefix_len,fqdn_fwd,fqdn_rev,hostname,state' as text) as result;
+\$\$ LANGUAGE SQL;
+--
+
+--
+--  FUNCTION that returns a result set containing the data for lease6 dumps
+DROP FUNCTION IF EXISTS lease6DumpData();
+CREATE FUNCTION lease6DumpData() RETURNS
+    TABLE (
+           address text,
+           duid text,
+           valid_lifetime bigint,
+           expire timestamp with time zone,
+           subnet_id bigint,
+           pref_lifetime bigint,
+           name text,
+           iaid integer,
+           prefix_len smallint,
+           fqdn_fwd int,
+           fqdn_rev int,
+           hostname text,
+           state text
+    ) AS \$\$
+    SELECT (l.address,
+            encode(l.duid,'hex'),
+            l.valid_lifetime,
+            l.expire,
+            l.subnet_id,
+            l.pref_lifetime,
+            t.name,
+            l.iaid,
+            l.prefix_len,
+            l.fqdn_fwd::int,
+            l.fqdn_rev::int,
+            l.hostname,
+            s.name)
+     FROM lease6 l
+         left outer join lease6_types t on (l.lease_type = t.lease_type)
+         left outer join lease_state s on (l.state = s.state);
+\$\$ LANGUAGE SQL;
+--
+
+-- Update the schema version number.
+START TRANSACTION;
+UPDATE schema_version
+    SET version = '2', minor = '0';
+
+-- This line concludes the schema upgrade to version 2.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_002.0_to_003.0.sh.in b/src/share/database/scripts/pgsql/upgrade_002.0_to_003.0.sh.in
new file mode 100644
index 0000000..266ce13
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_002.0_to_003.0.sh.in
@@ -0,0 +1,292 @@
+#!/bin/sh
+
+# Copyright (C) 2016-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "2.0" ]; then
+    printf 'This script upgrades 2.0 to 3.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 3.0.
+
+--
+-- Table structure for table host_identifier_type
+--
+
+CREATE TABLE host_identifier_type (
+  type SMALLINT PRIMARY KEY NOT NULL,
+  name VARCHAR(32) DEFAULT NULL
+);
+
+INSERT INTO host_identifier_type VALUES (0, 'hw-address');
+INSERT INTO host_identifier_type VALUES (1, 'duid');
+INSERT INTO host_identifier_type VALUES (2, 'circuit-id');
+
+CREATE TABLE dhcp_option_scope (
+  scope_id SMALLINT PRIMARY KEY NOT NULL,
+  scope_name varchar(32) DEFAULT NULL
+);
+
+INSERT INTO dhcp_option_scope VALUES (0, 'global');
+INSERT INTO dhcp_option_scope VALUES (1, 'subnet');
+INSERT INTO dhcp_option_scope VALUES (2, 'client-class');
+INSERT INTO dhcp_option_scope VALUES (3, 'host');
+
+--
+-- Table structure for table hosts
+--
+-- Primary key and unique constraints automatically create indexes
+-- foreign key constraints do not
+CREATE TABLE hosts (
+  host_id SERIAL PRIMARY KEY NOT NULL,
+  dhcp_identifier BYTEA NOT NULL,
+  dhcp_identifier_type SMALLINT NOT NULL,
+  dhcp4_subnet_id INT DEFAULT NULL,
+  dhcp6_subnet_id INT DEFAULT NULL,
+  ipv4_address BIGINT DEFAULT NULL,
+  hostname VARCHAR(255) DEFAULT NULL,
+  dhcp4_client_classes VARCHAR(255) DEFAULT NULL,
+  dhcp6_client_classes VARCHAR(255) DEFAULT NULL,
+  CONSTRAINT key_dhcp4_ipv4_address_subnet_id UNIQUE (ipv4_address, dhcp4_subnet_id),
+  CONSTRAINT key_dhcp4_identifier_subnet_id UNIQUE (dhcp_identifier, dhcp_identifier_type, dhcp4_subnet_id),
+  CONSTRAINT key_dhcp6_identifier_subnet_id UNIQUE (dhcp_identifier, dhcp_identifier_type, dhcp6_subnet_id),
+  CONSTRAINT fk_host_identifier_type FOREIGN KEY (dhcp_identifier_type) REFERENCES host_identifier_type (type)
+  ON DELETE CASCADE
+);
+
+CREATE INDEX fk_host_identifier_type ON hosts (dhcp_identifier_type);
+
+--
+-- Table structure for table dhcp4_options
+--
+
+CREATE TABLE dhcp4_options (
+  option_id SERIAL PRIMARY KEY NOT NULL,
+  code SMALLINT NOT NULL,
+  value BYTEA,
+  formatted_value TEXT,
+  space VARCHAR(128) DEFAULT NULL,
+  persistent BOOLEAN NOT NULL DEFAULT 'f',
+  dhcp_client_class VARCHAR(128) DEFAULT NULL,
+  dhcp4_subnet_id INT DEFAULT NULL,
+  host_id INT DEFAULT NULL,
+  scope_id SMALLINT NOT NULL,
+  CONSTRAINT fk_options_host1 FOREIGN KEY (host_id) REFERENCES hosts (host_id) ON DELETE CASCADE,
+  CONSTRAINT fk_dhcp4_option_scode FOREIGN KEY (scope_id) REFERENCES dhcp_option_scope (scope_id) ON DELETE CASCADE
+);
+
+CREATE INDEX fk_dhcp4_options_host1_idx ON dhcp4_options (host_id);
+CREATE INDEX fk_dhcp4_options_scope_idx ON dhcp4_options (scope_id);
+
+--
+-- Table structure for table dhcp6_options
+--
+
+CREATE TABLE dhcp6_options (
+  option_id SERIAL PRIMARY KEY NOT NULL,
+  code INT NOT NULL,
+  value BYTEA,
+  formatted_value TEXT,
+  space VARCHAR(128) DEFAULT NULL,
+  persistent BOOLEAN NOT NULL DEFAULT 'f',
+  dhcp_client_class VARCHAR(128) DEFAULT NULL,
+  dhcp6_subnet_id INT DEFAULT NULL,
+  host_id INT DEFAULT NULL,
+  scope_id SMALLINT NOT NULL,
+  CONSTRAINT fk_options_host10 FOREIGN KEY (host_id) REFERENCES hosts (host_id) ON DELETE CASCADE,
+  CONSTRAINT fk_dhcp6_option_scode FOREIGN KEY (scope_id) REFERENCES dhcp_option_scope (scope_id) ON DELETE CASCADE
+);
+
+CREATE INDEX fk_dhcp6_options_host1_idx ON dhcp6_options (host_id);
+CREATE INDEX fk_dhcp6_options_scope_idx ON dhcp6_options (scope_id);
+
+--
+-- Table structure for table ipv6_reservations
+--
+
+CREATE TABLE ipv6_reservations (
+  reservation_id SERIAL PRIMARY KEY NOT NULL,
+  address VARCHAR(39) NOT NULL,
+  prefix_len SMALLINT NOT NULL DEFAULT '128',
+  type SMALLINT NOT NULL DEFAULT '0',
+  dhcp6_iaid INT DEFAULT NULL,
+  host_id INT NOT NULL,
+  CONSTRAINT key_dhcp6_address_prefix_len UNIQUE (address, prefix_len),
+  CONSTRAINT fk_ipv6_reservations_host FOREIGN KEY (host_id) REFERENCES hosts (host_id) ON DELETE CASCADE
+);
+
+CREATE INDEX fk_ipv6_reservations_host_idx ON ipv6_reservations (host_id);
+
+--
+-- Table structure for table lease_hwaddr_source
+--
+
+CREATE TABLE lease_hwaddr_source (
+  hwaddr_source INT PRIMARY KEY NOT NULL,
+  name VARCHAR(40) DEFAULT NULL
+);
+
+-- In the event hardware address cannot be determined, we need to satisfy
+-- foreign key constraint between lease6 and lease_hardware_source
+INSERT INTO lease_hwaddr_source VALUES (0, 'HWADDR_SOURCE_UNKNOWN');
+
+-- Hardware address obtained from raw sockets
+INSERT INTO lease_hwaddr_source VALUES (1, 'HWADDR_SOURCE_RAW');
+
+-- Hardware address converted from IPv6 link-local address with EUI-64
+INSERT INTO lease_hwaddr_source VALUES (2, 'HWADDR_SOURCE_IPV6_LINK_LOCAL');
+
+-- Hardware address extracted from client-id (duid)
+INSERT INTO lease_hwaddr_source VALUES (4, 'HWADDR_SOURCE_DUID');
+
+-- Hardware address extracted from client address relay option (RFC6939)
+INSERT INTO lease_hwaddr_source VALUES (8, 'HWADDR_SOURCE_CLIENT_ADDR_RELAY_OPTION');
+
+-- Hardware address extracted from remote-id option (RFC4649)
+INSERT INTO lease_hwaddr_source VALUES (16, 'HWADDR_SOURCE_REMOTE_ID');
+
+-- Hardware address extracted from subscriber-id option (RFC4580)
+INSERT INTO lease_hwaddr_source VALUES (32, 'HWADDR_SOURCE_SUBSCRIBER_ID');
+
+-- Hardware address extracted from docsis options
+INSERT INTO lease_hwaddr_source VALUES (64, 'HWADDR_SOURCE_DOCSIS_CMTS');
+
+INSERT INTO lease_hwaddr_source VALUES (128, 'HWADDR_SOURCE_DOCSIS_MODEM');
+
+-- Adding ORDER BY clause to sort by lease address
+--
+--  FUNCTION that returns a result set containing the data for lease4 dumps
+DROP FUNCTION IF EXISTS lease4DumpData();
+CREATE FUNCTION lease4DumpData() RETURNS
+    table (address inet,
+           hwaddr text,
+           client_id text,
+           valid_lifetime bigint,
+           expire timestamp with time zone,
+           subnet_id bigint,
+           fqdn_fwd int,
+           fqdn_rev int,
+           hostname text,
+           state text
+    ) as \$\$
+    SELECT ('0.0.0.0'::inet + l.address),
+            encode(l.hwaddr,'hex'),
+            encode(l.client_id,'hex'),
+            l.valid_lifetime,
+            l.expire,
+            l.subnet_id,
+            l.fqdn_fwd::int,
+            l.fqdn_rev::int,
+            l.hostname,
+            s.name
+    FROM lease4 l
+         left outer join lease_state s on (l.state = s.state)
+    ORDER BY l.address;
+\$\$ LANGUAGE SQL;
+--
+
+-- Add new columns to lease6
+ALTER TABLE lease6
+  ADD COLUMN hwaddr BYTEA DEFAULT NULL,
+  ADD COLUMN hwtype SMALLINT DEFAULT NULL,
+  ADD COLUMN hwaddr_source SMALLINT DEFAULT NULL;
+
+--
+--  FUNCTION that returns a result set containing the column names for lease6 dumps
+DROP FUNCTION IF EXISTS lease6DumpHeader();
+CREATE FUNCTION lease6DumpHeader() RETURNS text AS  \$\$
+    select cast('address,duid,valid_lifetime,expire,subnet_id,pref_lifetime,lease_type,iaid,prefix_len,fqdn_fwd,fqdn_rev,hostname,state,hwaddr,hwtype,hwaddr_source' as text) as result;
+\$\$ LANGUAGE SQL;
+--
+
+--
+--  FUNCTION that returns a result set containing the data for lease6 dumps
+DROP FUNCTION IF EXISTS lease6DumpData();
+CREATE FUNCTION lease6DumpData() RETURNS
+    TABLE (
+           address text,
+           duid text,
+           valid_lifetime bigint,
+           expire timestamp with time zone,
+           subnet_id bigint,
+           pref_lifetime bigint,
+           name text,
+           iaid integer,
+           prefix_len smallint,
+           fqdn_fwd int,
+           fqdn_rev int,
+           hostname text,
+           state text,
+           hwaddr text,
+           hwtype smallint,
+           hwaddr_source text
+    ) AS \$\$
+    SELECT (l.address,
+            encode(l.duid,'hex'),
+            l.valid_lifetime,
+            l.expire,
+            l.subnet_id,
+            l.pref_lifetime,
+            t.name,
+            l.iaid,
+            l.prefix_len,
+            l.fqdn_fwd::int,
+            l.fqdn_rev::int,
+            l.hostname,
+            s.name,
+            encode(l.hwaddr,'hex'),
+            l.hwtype,
+            h.name
+     )
+     FROM lease6 l
+         left outer join lease6_types t on (l.lease_type = t.lease_type)
+         left outer join lease_state s on (l.state = s.state)
+         left outer join lease_hwaddr_source h on (l.hwaddr_source = h.hwaddr_source)
+     ORDER BY l.address;
+\$\$ LANGUAGE SQL;
+
+-- Add columns holding reservations for siaddr, sname and file fields
+-- carried within DHCPv4 message.
+ALTER TABLE hosts ADD COLUMN dhcp4_next_server BIGINT DEFAULT NULL;
+ALTER TABLE hosts ADD COLUMN dhcp4_server_hostname VARCHAR(64) DEFAULT NULL;
+ALTER TABLE hosts ADD COLUMN dhcp4_boot_file_name VARCHAR(128) DEFAULT NULL;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '3', minor = '0';
+
+-- This line concludes the schema upgrade to version 3.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_003.0_to_003.1.sh.in b/src/share/database/scripts/pgsql/upgrade_003.0_to_003.1.sh.in
new file mode 100644
index 0000000..53df10c
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_003.0_to_003.1.sh.in
@@ -0,0 +1,64 @@
+#!/bin/sh
+
+# Copyright (C) 2017-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "3.0" ]; then
+    printf 'This script upgrades 3.0 to 3.1. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 3.1.
+
+-- The 'client-id' host identifier type was missing in the
+-- 2.0 -> 3.0 upgrade script. However, it was present in the
+-- dhcpdb_create.pgsql file. This means that this entry may
+-- or may not be present. By the conditional insert below we
+-- will only insert it if it doesn't exist.
+INSERT INTO host_identifier_type (type, name)
+  SELECT 3, 'client-id'
+    WHERE NOT EXISTS (
+        SELECT type FROM host_identifier_type WHERE type = 3
+    );
+
+-- We also add a new identifier type: flex-id.
+INSERT INTO host_identifier_type VALUES (4, 'flex-id');
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '3', minor = '1';
+
+-- This line concludes the schema upgrade to version 3.1.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_003.1_to_003.2.sh.in b/src/share/database/scripts/pgsql/upgrade_003.1_to_003.2.sh.in
new file mode 100644
index 0000000..a2f31b1
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_003.1_to_003.2.sh.in
@@ -0,0 +1,79 @@
+#!/bin/sh
+
+# Copyright (C) 2017-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "3.1" ]; then
+    printf 'This script upgrades 3.1 to 3.2. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 3.2.
+
+-- Remove constraints which perform too restrictive checks on the inserted
+-- host reservations. We want to be able to insert host reservations which
+-- include no specific IPv4 address or those that have repeating subnet
+-- identifiers, e.g. IPv4 reservations would typically include 0 (or null)
+-- IPv6 subnet identifiers.
+ALTER TABLE hosts DROP CONSTRAINT key_dhcp4_ipv4_address_subnet_id;
+ALTER TABLE hosts DROP CONSTRAINT key_dhcp4_identifier_subnet_id;
+ALTER TABLE hosts DROP CONSTRAINT key_dhcp6_identifier_subnet_id;
+
+-- Create partial indexes instead of the constraints that we have removed.
+
+-- IPv4 address/IPv4 subnet identifier pair is unique if subnet identifier is
+-- not null and not 0.
+CREATE UNIQUE INDEX hosts_dhcp4_ipv4_address_subnet_id ON hosts
+       (ipv4_address ASC, dhcp4_subnet_id ASC)
+    WHERE ipv4_address IS NOT NULL AND ipv4_address <> 0;
+
+-- Client identifier is unique within an IPv4 subnet when subnet identifier is
+-- not null and not 0.
+CREATE UNIQUE INDEX hosts_dhcp4_identifier_subnet_id ON hosts
+        (dhcp_identifier ASC, dhcp_identifier_type ASC, dhcp4_subnet_id ASC)
+    WHERE (dhcp4_subnet_id IS NOT NULL AND dhcp4_subnet_id <> 0);
+
+-- Client identifier is unique within an IPv6 subnet when subnet identifier is
+-- not null and not 0.
+CREATE UNIQUE INDEX hosts_dhcp6_identifier_subnet_id ON hosts
+        (dhcp_identifier ASC, dhcp_identifier_type ASC, dhcp6_subnet_id ASC)
+    WHERE (dhcp6_subnet_id IS NOT NULL AND dhcp6_subnet_id <> 0);
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '3', minor = '2';
+
+-- This line concludes the schema upgrade to version 3.2.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_003.2_to_003.3.sh.in b/src/share/database/scripts/pgsql/upgrade_003.2_to_003.3.sh.in
new file mode 100644
index 0000000..84cfb2d
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_003.2_to_003.3.sh.in
@@ -0,0 +1,57 @@
+#!/bin/sh
+
+# Copyright (C) 2018-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "3.2" ]; then
+    printf 'This script upgrades 3.2 to 3.3. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 3.3.
+
+-- Change subnet ID columns type to BIGINT to match lease4/6 tables
+ALTER TABLE hosts ALTER COLUMN dhcp4_subnet_id TYPE BIGINT;
+ALTER TABLE hosts ALTER COLUMN dhcp6_subnet_id TYPE BIGINT;
+
+ALTER TABLE dhcp4_options ALTER COLUMN dhcp4_subnet_id TYPE BIGINT;
+ALTER TABLE dhcp6_options ALTER COLUMN dhcp6_subnet_id TYPE BIGINT;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '3', minor = '3';
+
+-- This line concludes the schema upgrade to version 3.3.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_003.3_to_004.0.sh.in b/src/share/database/scripts/pgsql/upgrade_003.3_to_004.0.sh.in
new file mode 100644
index 0000000..e460ef7
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_003.3_to_004.0.sh.in
@@ -0,0 +1,262 @@
+#!/bin/sh
+
+# Copyright (C) 2018-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "3.3" ]; then
+    printf 'This script upgrades 3.3 to 4.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 4.0.
+
+-- Add a column holding hosts for user context.
+ALTER TABLE hosts ADD COLUMN user_context TEXT;
+
+-- Add a column holding DHCP options for user context.
+ALTER TABLE dhcp4_options ADD COLUMN user_context TEXT;
+ALTER TABLE dhcp6_options ADD COLUMN user_context TEXT;
+
+-- Create index for searching leases by subnet identifier.
+CREATE INDEX lease4_by_subnet_id ON lease4 (subnet_id);
+
+-- Create for searching leases by subnet identifier and lease type.
+CREATE INDEX lease6_by_subnet_id_lease_type ON lease6 (subnet_id, lease_type);
+
+-- The index by iaid_subnet_id_duid is not the best choice because there are
+-- cases when we don't specify subnet identifier while searching leases. The
+-- index will be universal if the subnet_id is the right most column in the
+-- index.
+DROP INDEX lease6_by_iaid_subnet_id_duid;
+CREATE INDEX lease6_by_duid_iaid_subnet_id ON lease6 (duid, iaid, subnet_id);
+
+-- Create v4 lease statistics table
+CREATE TABLE lease4_stat (
+    subnet_id BIGINT NOT NULL,
+    state INT8 NOT NULL,
+    leases BIGINT,
+    PRIMARY KEY (subnet_id, state)
+);
+
+--
+-- Create v4 insert trigger procedure
+CREATE FUNCTION proc_stat_lease4_insert () RETURNS trigger AS \$stat_lease4_insert\$
+BEGIN
+    IF NEW.state < 2 THEN
+        UPDATE lease4_stat
+            SET leases = leases + 1
+            WHERE subnet_id = NEW.subnet_id AND state = NEW.state;
+
+        IF NOT FOUND THEN
+            INSERT INTO lease4_stat VALUES (new.subnet_id, new.state, 1);
+        END IF;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+\$stat_lease4_insert\$ LANGUAGE plpgsql;
+
+-- Create v4 insert trigger procedure
+CREATE TRIGGER stat_lease4_insert
+AFTER INSERT ON lease4
+    FOR EACH ROW EXECUTE PROCEDURE proc_stat_lease4_insert();
+
+--
+-- Create v4 update trigger procedure
+CREATE FUNCTION proc_stat_lease4_update () RETURNS trigger AS \$stat_lease4_update\$
+BEGIN
+    IF OLD.state != NEW.state THEN
+        IF OLD.state < 2 THEN
+            -- Decrement the old state count if record exists
+            UPDATE lease4_stat SET leases = leases - 1
+            WHERE subnet_id = OLD.subnet_id AND state = OLD.state;
+        END IF;
+
+        IF NEW.state < 2 THEN
+            -- Increment the new state count if record exists
+            UPDATE lease4_stat SET leases = leases + 1
+            WHERE subnet_id = NEW.subnet_id AND state = NEW.state;
+
+            -- Insert new state record if it does not exist
+            IF NOT FOUND THEN
+                INSERT INTO lease4_stat VALUES (NEW.subnet_id, NEW.state, 1);
+            END IF;
+        END IF;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+\$stat_lease4_update\$ LANGUAGE plpgsql;
+
+-- Create v4 update trigger
+CREATE TRIGGER stat_lease4_update
+AFTER UPDATE ON lease4
+    FOR EACH ROW EXECUTE PROCEDURE proc_stat_lease4_update();
+
+--
+-- Create the v4 delete trigger procedure
+CREATE FUNCTION proc_stat_lease4_delete () RETURNS trigger AS \$stat_lease4_delete\$
+BEGIN
+    IF OLD.state < 2 THEN
+        -- Decrement the state count if record exists
+        UPDATE lease4_stat SET leases = leases - 1
+        WHERE subnet_id = OLD.subnet_id AND OLD.state = state;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+\$stat_lease4_delete\$ LANGUAGE plpgsql;
+
+-- Create the v4 delete trigger
+CREATE TRIGGER stat_lease4_delete
+AFTER DELETE ON lease4
+    FOR EACH ROW EXECUTE PROCEDURE proc_stat_lease4_delete();
+
+-- Create v6 lease statistics table
+CREATE TABLE lease6_stat (
+    subnet_id BIGINT NOT NULL,
+    lease_type SMALLINT NOT NULL,
+    state INT8 NOT NULL,
+    leases BIGINT,
+    PRIMARY KEY (subnet_id, lease_type, state)
+);
+
+--
+-- Create v6 insert trigger procedure
+CREATE FUNCTION proc_stat_lease6_insert () RETURNS trigger AS \$stat_lease6_insert\$
+BEGIN
+    IF NEW.state < 2 THEN
+        UPDATE lease6_stat
+        SET leases = leases + 1
+        WHERE
+        subnet_id = NEW.subnet_id AND lease_type = NEW.lease_type
+        AND state = NEW.state;
+
+        IF NOT FOUND THEN
+            INSERT INTO lease6_stat
+            VALUES (NEW.subnet_id, NEW.lease_type, NEW.state, 1);
+        END IF;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+\$stat_lease6_insert\$ LANGUAGE plpgsql;
+
+-- Create v6 insert trigger procedure
+CREATE TRIGGER stat_lease6_insert
+AFTER INSERT ON lease6
+    FOR EACH ROW EXECUTE PROCEDURE proc_stat_lease6_insert();
+
+--
+-- Create v6 update trigger procedure
+CREATE FUNCTION proc_stat_lease6_update () RETURNS trigger AS \$stat_lease6_update\$
+BEGIN
+    IF OLD.state != NEW.state THEN
+        IF OLD.state < 2 THEN
+            -- Decrement the old state count if record exists
+            UPDATE lease6_stat SET leases = leases - 1
+            WHERE subnet_id = OLD.subnet_id AND lease_type = OLD.lease_type
+            AND state = OLD.state;
+        END IF;
+
+        IF NEW.state < 2 THEN
+            -- Increment the new state count if record exists
+            UPDATE lease6_stat SET leases = leases + 1
+            WHERE subnet_id = NEW.subnet_id AND lease_type = NEW.lease_type
+            AND state = NEW.state;
+
+            -- Insert new state record if it does not exist
+            IF NOT FOUND THEN
+                INSERT INTO lease6_stat VALUES (NEW.subnet_id, NEW.lease_type, NEW.state, 1);
+            END IF;
+        END IF;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+\$stat_lease6_update\$ LANGUAGE plpgsql;
+
+-- Create v6 update trigger
+CREATE TRIGGER stat_lease6_update
+AFTER UPDATE ON lease6
+    FOR EACH ROW EXECUTE PROCEDURE proc_stat_lease6_update();
+
+--
+-- Create the v6 delete trigger procedure
+CREATE FUNCTION proc_stat_lease6_delete() RETURNS trigger AS \$stat_lease6_delete\$
+BEGIN
+    IF OLD.state < 2 THEN
+        -- Decrement the state count if record exists
+        UPDATE lease6_stat SET leases = leases - 1
+        WHERE subnet_id = OLD.subnet_id AND lease_type = OLD.lease_type
+        AND OLD.state = state;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+\$stat_lease6_delete\$ LANGUAGE plpgsql;
+
+-- Create the v6 delete trigger
+CREATE TRIGGER stat_lease6_delete
+AFTER DELETE ON lease6
+    FOR EACH ROW EXECUTE PROCEDURE proc_stat_lease6_delete();
+
+-- Populate lease4_stat table based on existing leases
+-- We only care about assigned and declined states
+INSERT INTO lease4_stat (subnet_id, state, leases)
+    SELECT subnet_id, state, count(state)
+    FROM lease4 WHERE state < 2
+    GROUP BY subnet_id, state ORDER BY subnet_id;
+
+-- Populate lease6_stat table based on existing leases
+-- We only care about assigned and declined states
+INSERT INTO lease6_stat (subnet_id, lease_type, state, leases)
+    SELECT subnet_id, lease_type, state, count(state)
+    FROM lease6 WHERE state < 2
+    GROUP BY subnet_id, lease_type, state
+    ORDER BY subnet_id;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '4', minor = '0';
+
+-- This line concludes the schema upgrade to version 4.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_004.0_to_005.0.sh.in b/src/share/database/scripts/pgsql/upgrade_004.0_to_005.0.sh.in
new file mode 100644
index 0000000..244cde2
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_004.0_to_005.0.sh.in
@@ -0,0 +1,173 @@
+#!/bin/sh
+
+# Copyright (C) 2018-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "4.0" ]; then
+    printf 'This script upgrades 4.0 to 5.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 5.0.
+
+-- Add a column holding leases for user context.
+ALTER TABLE lease4 ADD COLUMN user_context TEXT;
+ALTER TABLE lease6 ADD COLUMN user_context TEXT;
+
+--
+--  FUNCTION that returns a result set containing the column names for lease4 dumps
+DROP FUNCTION IF EXISTS lease4DumpHeader();
+CREATE FUNCTION lease4DumpHeader() RETURNS text AS  \$\$
+    select cast('address,hwaddr,client_id,valid_lifetime,expire,subnet_id,fqdn_fwd,fqdn_rev,hostname,state,user_context' as text) as result;
+\$\$ LANGUAGE SQL;
+--
+
+--
+--  FUNCTION that returns a result set containing the data for lease4 dumps
+DROP FUNCTION IF EXISTS lease4DumpData();
+CREATE FUNCTION lease4DumpData() RETURNS
+    table (address inet,
+           hwaddr text,
+           client_id text,
+           valid_lifetime bigint,
+           expire timestamp with time zone,
+           subnet_id bigint,
+           fqdn_fwd int,
+           fqdn_rev int,
+           hostname text,
+           state text,
+           user_context text
+    ) as \$\$
+    SELECT ('0.0.0.0'::inet + l.address),
+            encode(l.hwaddr,'hex'),
+            encode(l.client_id,'hex'),
+            l.valid_lifetime,
+            l.expire,
+            l.subnet_id,
+            l.fqdn_fwd::int,
+            l.fqdn_rev::int,
+            l.hostname,
+            s.name,
+            l.user_context
+    FROM lease4 l
+         left outer join lease_state s on (l.state = s.state)
+    ORDER BY l.address;
+\$\$ LANGUAGE SQL;
+--
+
+--
+--  FUNCTION that returns a result set containing the column names for lease6 dumps
+DROP FUNCTION IF EXISTS lease6DumpHeader();
+CREATE FUNCTION lease6DumpHeader() RETURNS text AS  \$\$
+    select cast('address,duid,valid_lifetime,expire,subnet_id,pref_lifetime,lease_type,iaid,prefix_len,fqdn_fwd,fqdn_rev,hostname,state,hwaddr,hwtype,hwaddr_source,user_context' as text) as result;
+\$\$ LANGUAGE SQL;
+--
+
+--
+--  FUNCTION that returns a result set containing the data for lease6 dumps
+DROP FUNCTION IF EXISTS lease6DumpData();
+CREATE FUNCTION lease6DumpData() RETURNS
+    TABLE (
+           address text,
+           duid text,
+           valid_lifetime bigint,
+           expire timestamp with time zone,
+           subnet_id bigint,
+           pref_lifetime bigint,
+           name text,
+           iaid integer,
+           prefix_len smallint,
+           fqdn_fwd int,
+           fqdn_rev int,
+           hostname text,
+           state text,
+           hwaddr text,
+           hwtype smallint,
+           hwaddr_source text,
+           user_context text
+    ) AS \$\$
+    SELECT (l.address,
+            encode(l.duid,'hex'),
+            l.valid_lifetime,
+            l.expire,
+            l.subnet_id,
+            l.pref_lifetime,
+            t.name,
+            l.iaid,
+            l.prefix_len,
+            l.fqdn_fwd::int,
+            l.fqdn_rev::int,
+            l.hostname,
+            s.name,
+            encode(l.hwaddr,'hex'),
+            l.hwtype,
+            h.name,
+            l.user_context
+     )
+     FROM lease6 l
+         left outer join lease6_types t on (l.lease_type = t.lease_type)
+         left outer join lease_state s on (l.state = s.state)
+         left outer join lease_hwaddr_source h on (l.hwaddr_source = h.hwaddr_source)
+     ORDER BY l.address;
+\$\$ LANGUAGE SQL;
+--
+
+-- Create logs table (logs table is used by forensic logging hook library)
+CREATE TABLE logs (
+    timestamp TIMESTAMP WITH TIME ZONE
+    DEFAULT CURRENT_TIMESTAMP,          -- creation timestamp
+    address VARCHAR(43) NULL,           -- address or prefix
+    log TEXT NOT NULL                   -- the log itself
+    );
+
+-- Create search indexes
+CREATE INDEX timestamp_id ON logs (timestamp);
+CREATE INDEX address_id ON logs (address);
+
+-- Create auth_key in hosts table for storing keys for DHCPv6 reconfigure.
+ALTER TABLE hosts ADD COLUMN auth_key  VARCHAR(16) DEFAULT NULL;
+
+-- Convert subnet-id values of 0  to NULL
+UPDATE hosts SET dhcp4_subnet_id = NULL WHERE dhcp4_subnet_id = 0;
+UPDATE dhcp4_options SET dhcp4_subnet_id = NULL WHERE dhcp4_subnet_id = 0;
+UPDATE hosts SET dhcp6_subnet_id = NULL WHERE dhcp6_subnet_id = 0;
+UPDATE dhcp6_options SET dhcp6_subnet_id = NULL WHERE dhcp6_subnet_id = 0;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '5', minor = '0';
+
+-- This line concludes the schema upgrade to version 5.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_005.0_to_005.1.sh.in b/src/share/database/scripts/pgsql/upgrade_005.0_to_005.1.sh.in
new file mode 100644
index 0000000..e273975
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_005.0_to_005.1.sh.in
@@ -0,0 +1,53 @@
+#!/bin/sh
+
+# Copyright (C) 2019-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "5.0" ]; then
+    printf 'This script upgrades 5.0 to 5.1. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 5.1.
+
+-- Put the auth key in hexadecimal (double size but far more user friendly).
+ALTER TABLE hosts ALTER COLUMN auth_key TYPE VARCHAR(32);
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '5', minor = '1';
+
+-- This line concludes the schema upgrade to version 5.1.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_005.1_to_006.0.sh.in b/src/share/database/scripts/pgsql/upgrade_005.1_to_006.0.sh.in
new file mode 100644
index 0000000..88b53de
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_005.1_to_006.0.sh.in
@@ -0,0 +1,72 @@
+#!/bin/sh
+
+# Copyright (C) 2019-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "5.1" ]; then
+    printf 'This script upgrades 5.1 to 6.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 6.0.
+
+-- Create a lower case hostname index for hosts.
+CREATE INDEX hosts_by_hostname ON hosts (lower(hostname))
+WHERE hostname IS NOT NULL;
+
+-- Create a hostname index for lease4.
+CREATE INDEX lease4_by_hostname ON lease4 (lower(hostname))
+WHERE hostname IS NOT NULL;
+
+-- Create a hostname index for lease6.
+CREATE INDEX lease6_by_hostname ON lease6 (lower(hostname))
+WHERE hostname IS NOT NULL;
+
+-- Move to lower case hostnames in lease4 table.
+-- Not required so in comment
+-- UPDATE lease4 SET hostname = lower(hostname)
+-- WHERE lower(hostname) != hostname;
+
+-- Move to lower case hostnames in lease6 table.
+-- Not required so in comment
+-- UPDATE lease6 SET hostname = lower(hostname)
+-- WHERE lower(hostname) != hostname;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '6', minor = '0';
+
+-- This line concludes the schema upgrade to version 6.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_006.0_to_006.1.sh.in b/src/share/database/scripts/pgsql/upgrade_006.0_to_006.1.sh.in
new file mode 100644
index 0000000..54b044c
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_006.0_to_006.1.sh.in
@@ -0,0 +1,140 @@
+#!/bin/sh
+
+# Copyright (C) 2020-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "6.0" ]; then
+    printf 'This script upgrades 6.0 to 6.1. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 6.1.
+
+-- Fix v4 update trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease4_update () RETURNS trigger AS \$stat_lease4_update\$
+BEGIN
+    IF OLD.subnet_id != NEW.subnet_id OR OLD.state != NEW.state THEN
+        IF OLD.state < 2 THEN
+            -- Decrement the old state count if record exists
+            UPDATE lease4_stat SET leases = GREATEST(leases - 1, 0)
+            WHERE subnet_id = OLD.subnet_id AND state = OLD.state;
+        END IF;
+
+        IF NEW.state < 2 THEN
+            -- Increment the new state count if record exists
+            UPDATE lease4_stat SET leases = leases + 1
+            WHERE subnet_id = NEW.subnet_id AND state = NEW.state;
+
+            -- Insert new state record if it does not exist
+            IF NOT FOUND THEN
+                INSERT INTO lease4_stat VALUES (NEW.subnet_id, NEW.state, 1);
+            END IF;
+        END IF;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+\$stat_lease4_update\$ LANGUAGE plpgsql;
+
+--
+-- Fix the v4 delete trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease4_delete () RETURNS trigger AS \$stat_lease4_delete\$
+BEGIN
+    IF OLD.state < 2 THEN
+        -- Decrement the state count if record exists
+        UPDATE lease4_stat SET leases = GREATEST(leases - 1, 0)
+        WHERE subnet_id = OLD.subnet_id AND OLD.state = state;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+\$stat_lease4_delete\$ LANGUAGE plpgsql;
+
+--
+-- Fix v6 update trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease6_update () RETURNS trigger AS \$stat_lease6_update\$
+BEGIN
+    IF OLD.subnet_id != NEW.subnet_id OR
+       OLD.lease_type != NEW.lease_type OR
+       OLD.state != NEW.state THEN
+        IF OLD.state < 2 THEN
+            -- Decrement the old state count if record exists
+            UPDATE lease6_stat SET leases = GREATEST(leases - 1, 0)
+            WHERE subnet_id = OLD.subnet_id AND lease_type = OLD.lease_type
+            AND state = OLD.state;
+        END IF;
+
+        IF NEW.state < 2 THEN
+            -- Increment the new state count if record exists
+            UPDATE lease6_stat SET leases = leases + 1
+            WHERE subnet_id = NEW.subnet_id AND lease_type = NEW.lease_type
+            AND state = NEW.state;
+
+            -- Insert new state record if it does not exist
+            IF NOT FOUND THEN
+                INSERT INTO lease6_stat VALUES (NEW.subnet_id, NEW.lease_type, NEW.state, 1);
+            END IF;
+        END IF;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+\$stat_lease6_update\$ LANGUAGE plpgsql;
+
+--
+-- Fix the v6 delete trigger procedure
+CREATE OR REPLACE FUNCTION proc_stat_lease6_delete() RETURNS trigger AS \$stat_lease6_delete\$
+BEGIN
+    IF OLD.state < 2 THEN
+        -- Decrement the state count if record exists
+        UPDATE lease6_stat SET leases = GREATEST(leases - 1, 0)
+        WHERE subnet_id = OLD.subnet_id AND lease_type = OLD.lease_type
+        AND OLD.state = state;
+    END IF;
+
+    -- Return is ignored since this is an after insert
+    RETURN NULL;
+END;
+\$stat_lease6_delete\$ LANGUAGE plpgsql;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '6', minor = '1';
+
+-- This line concludes the schema upgrade to version 6.1.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_006.1_to_006.2.sh.in b/src/share/database/scripts/pgsql/upgrade_006.1_to_006.2.sh.in
new file mode 100644
index 0000000..6fd4462
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_006.1_to_006.2.sh.in
@@ -0,0 +1,75 @@
+#!/bin/sh
+
+# Copyright (C) 2020-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "6.1" ]; then
+    printf 'This script upgrades 6.1 to 6.2. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 6.2.
+
+-- Starting from this version we allow specifying multiple IP reservations
+-- for the same address in certain DHCP configurations. The server may check
+-- uniqueness of the IP addresses on its own. This is no longer checked at
+-- the database level to facilitate the use cases when a single host may
+-- get the same reserved IP address via different interfaces.
+
+-- Replace the unique index with non-unique index so the queries for
+-- hosts by IPv4 address are still efficient.
+--
+-- Note we have introduced a bug a while ago which causes the index to have
+-- different names depending on whether the schema was created via the
+-- dhcpdb_create.pgsql script or via updates. Therefore, let's make sure
+-- that we drop the index regardless of its current name.
+DROP INDEX IF EXISTS key_dhcp4_ipv4_address_subnet_id;
+DROP INDEX IF EXISTS hosts_dhcp4_ipv4_address_subnet_id;
+CREATE INDEX key_dhcp4_ipv4_address_subnet_id
+    ON hosts (ipv4_address ASC, dhcp4_subnet_id ASC);
+
+-- Replace the unique index with non-unique index so the queries for
+-- hosts by IPv6 address are still efficient.
+ALTER TABLE ipv6_reservations DROP CONSTRAINT IF EXISTS key_dhcp6_address_prefix_len;
+CREATE INDEX key_dhcp6_address_prefix_len
+    ON ipv6_reservations (address ASC, prefix_len ASC);
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '6', minor = '2';
+
+-- This line concludes the schema upgrade to version 6.2.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_006.2_to_007.0.sh.in b/src/share/database/scripts/pgsql/upgrade_006.2_to_007.0.sh.in
new file mode 100644
index 0000000..a62903a
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_006.2_to_007.0.sh.in
@@ -0,0 +1,2745 @@
+#!/bin/sh
+
+# Copyright (C) 2021-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "6.2" ]; then
+    printf 'This script upgrades 6.2 to 7.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 7.0.
+
+-- Add a lot (20+) of tables for the config backend.
+
+-- Adding on update trigger in MySQL is as easy as using this column definition in CREATE TABLE:
+-- modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+-- Sadly, Postgres has its own convoluted way of doing this. Luckily, the update pattern is
+-- the same in many tables, so we can define the trigger function once and the use it everywhere.
+
+-- First, we need to define a function that will do the actual job.
+-- This is used in many, many tables.
+CREATE OR REPLACE FUNCTION modification_ts_update()
+  RETURNS trigger AS \$modification_ts_update\$
+  BEGIN
+    new.modification_ts = CURRENT_TIMESTAMP;
+    RETURN NULL;
+  END;
+
+-- Second, we need to specify which language it was written in.
+\$modification_ts_update\$ LANGUAGE plpgsql;
+
+-- Create table modification and insert values for modification types.
+CREATE TABLE modification (
+  id smallint NOT NULL,
+  modification_type VARCHAR(32) NOT NULL,
+  PRIMARY KEY (id)
+);
+INSERT INTO modification VALUES (0,'create'), (1,'update'), (2,'delete');
+
+-- Now create the table that holds different parameter data types.
+CREATE TABLE parameter_data_type (
+  id smallint NOT NULL,
+  name VARCHAR(32) NOT NULL,
+  PRIMARY KEY (id)
+);
+INSERT INTO parameter_data_type VALUES
+    (0,'integer'),
+    (1,'real'),
+    (2,'boolean'),
+    (4,'string');
+
+-- This table doesn't exist in MySQL. However, it's nice to have an enum that explains what the values
+-- in ddns_replace_client_name field in the dhcp{4,6}_shared_network table means.
+CREATE TABLE ddns_replace_client_name_types (
+  type INT8 PRIMARY KEY NOT NULL,
+  name VARCHAR(32)
+);
+-- See enum ReplaceClientNameMode in src/lib/dhcpsrv/d2_client_cfg.h
+INSERT INTO ddns_replace_client_name_types (type, name) VALUES
+  (0, 'RCM_NEVER'),
+  (1, 'RCM_ALWAYS'),
+  (2, 'RCM_WHEN_PRESENT'),
+  (3, 'RCM_WHEN_NOT_PRESENT');
+
+-- Create table for DHCPv6 servers
+CREATE TABLE dhcp6_server (
+  id SERIAL PRIMARY KEY NOT NULL,
+  tag VARCHAR(64) NOT NULL,
+  description TEXT DEFAULT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  UNIQUE(tag)
+);
+CREATE INDEX dhcp6_server_idx1 ON dhcp6_server (modification_ts);
+CREATE UNIQUE INDEX dhcp6_server_idx2 ON dhcp6_server(tag);
+CREATE TRIGGER dhcp6_server_modification_ts_update
+  AFTER UPDATE ON dhcp6_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+INSERT INTO dhcp6_server (tag, description) VALUES ('all','special type: all servers');
+
+-- Create a table for storing IPv6 shared networks
+CREATE TABLE dhcp6_shared_network (
+  id SERIAL PRIMARY KEY NOT NULL,
+  name VARCHAR(128) UNIQUE NOT NULL,
+  client_class VARCHAR(128) DEFAULT NULL,
+  interface VARCHAR(128) DEFAULT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  preferred_lifetime BIGINT DEFAULT NULL,
+  rapid_commit BOOLEAN DEFAULT NULL,
+  rebind_timer BIGINT DEFAULT NULL,
+  relay TEXT DEFAULT NULL,
+  renew_timer BIGINT DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  valid_lifetime BIGINT DEFAULT NULL,
+  calculate_tee_times BOOLEAN DEFAULT NULL,
+  t1_percent float DEFAULT NULL,
+  t2_percent float DEFAULT NULL,
+  interface_id BYTEA DEFAULT NULL, -- 128 bytes
+  min_preferred_lifetime BIGINT DEFAULT NULL,
+  max_preferred_lifetime BIGINT DEFAULT NULL,
+  min_valid_lifetime BIGINT DEFAULT NULL,
+  max_valid_lifetime BIGINT DEFAULT NULL,
+  ddns_send_updates BOOLEAN DEFAULT NULL,
+  ddns_override_no_update BOOLEAN DEFAULT NULL,
+  ddns_override_client_update BOOLEAN DEFAULT NULL,
+  ddns_replace_client_name INT8 DEFAULT NULL,
+  ddns_generated_prefix VARCHAR(255) DEFAULT NULL,
+  ddns_qualifying_suffix VARCHAR(255) DEFAULT NULL,
+  reservations_global BOOLEAN DEFAULT NULL,
+  reservations_in_subnet BOOLEAN DEFAULT NULL,
+  reservations_out_of_pool BOOLEAN DEFAULT NULL,
+  cache_threshold float DEFAULT NULL,
+  cache_max_age BIGINT DEFAULT NULL,
+  CONSTRAINT fk_ddns_replace_client_name FOREIGN KEY (ddns_replace_client_name)
+    REFERENCES ddns_replace_client_name_types (type)
+);
+CREATE INDEX dhcp6_shared_network_idx1 ON dhcp6_shared_network (name);
+
+CREATE TRIGGER dhcp6_shared_network_modification_ts_update
+  AFTER UPDATE ON dhcp6_shared_network
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Now we need to create a relationship between defined shared networks and the servers
+CREATE TABLE dhcp6_shared_network_server (
+  shared_network_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (shared_network_id, server_id),
+  CONSTRAINT fk_dhcp6_shared_network_server_server_id FOREIGN KEY (server_id)
+    REFERENCES dhcp6_server (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp6_shared_network_server_shared_network_id FOREIGN KEY (shared_network_id)
+    REFERENCES dhcp6_shared_network (id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+CREATE INDEX dhcp6_shared_network_server_idx1 ON dhcp6_shared_network_server (modification_ts);
+CREATE INDEX dhcp6_shared_network_server_idx2 ON dhcp6_shared_network_server (server_id);
+
+-- Create a list of IPv6 subnets
+CREATE TABLE dhcp6_subnet (
+  subnet_id BIGINT PRIMARY KEY NOT NULL,
+  subnet_prefix VARCHAR(64) UNIQUE NOT NULL,
+  client_class VARCHAR(128) DEFAULT NULL,
+  interface VARCHAR(128) DEFAULT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  preferred_lifetime BIGINT DEFAULT NULL,
+  rapid_commit BOOLEAN DEFAULT NULL,
+  rebind_timer BIGINT DEFAULT NULL,
+  relay TEXT DEFAULT NULL,
+  renew_timer BIGINT DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  shared_network_name VARCHAR(128) DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  valid_lifetime BIGINT DEFAULT NULL,
+  calculate_tee_times BOOLEAN DEFAULT NULL,
+  t1_percent float DEFAULT NULL,
+  t2_percent float DEFAULT NULL,
+  interface_id BYTEA DEFAULT NULL,
+  min_preferred_lifetime BIGINT DEFAULT NULL,
+  max_preferred_lifetime BIGINT DEFAULT NULL,
+  min_valid_lifetime BIGINT DEFAULT NULL,
+  max_valid_lifetime BIGINT DEFAULT NULL,
+  ddns_send_updates BOOLEAN DEFAULT NULL,
+  ddns_override_no_update BOOLEAN DEFAULT NULL,
+  ddns_override_client_update BOOLEAN DEFAULT NULL,
+  ddns_replace_client_name INT8 DEFAULT NULL,
+  ddns_generated_prefix VARCHAR(255) DEFAULT NULL,
+  ddns_qualifying_suffix VARCHAR(255) DEFAULT NULL,
+  reservations_global BOOLEAN DEFAULT NULL,
+  reservations_in_subnet BOOLEAN DEFAULT NULL,
+  reservations_out_of_pool BOOLEAN DEFAULT NULL,
+  cache_threshold float DEFAULT NULL,
+  cache_max_age BIGINT DEFAULT NULL,
+  CONSTRAINT fk_dhcp6_subnet_shared_network FOREIGN KEY (shared_network_name)
+    REFERENCES dhcp6_shared_network (name) ON DELETE SET NULL ON UPDATE NO ACTION,
+  CONSTRAINT fk_ddns_replace_client_name FOREIGN KEY (ddns_replace_client_name)
+    REFERENCES ddns_replace_client_name_types (type)
+);
+
+CREATE TRIGGER dhcp6_subnet_modification_ts_update
+  AFTER UPDATE ON dhcp6_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+CREATE INDEX dhcp6_subnet_idx1 ON dhcp6_subnet (modification_ts);
+CREATE INDEX dhcp6_subnet_idx2 ON dhcp6_subnet (shared_network_name);
+
+-- Create a table that holds all address pools in IPv6.
+CREATE TABLE dhcp6_pool (
+  id SERIAL PRIMARY KEY NOT NULL,
+  start_address inet NOT NULL,
+  end_address inet NOT NULL,
+  subnet_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  client_class VARCHAR(128) DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  CONSTRAINT fk_dhcp6_pool_subnet_id FOREIGN KEY (subnet_id) REFERENCES dhcp6_subnet (subnet_id)
+);
+CREATE INDEX dhcp6_pool_idx1 ON dhcp6_pool (modification_ts);
+CREATE INDEX dhcp6_pool_idx2 ON dhcp6_pool (subnet_id);
+
+CREATE TRIGGER dhcp6_pool_modification_ts_update
+  AFTER UPDATE ON dhcp6_pool
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- And now the same, but for PD pools.
+CREATE TABLE dhcp6_pd_pool (
+  id SERIAL PRIMARY KEY NOT NULL,
+  prefix VARCHAR(45) NOT NULL,
+  prefix_length SMALLINT NOT NULL,
+  delegated_prefix_length SMALLINT NOT NULL,
+  subnet_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  excluded_prefix VARCHAR(45) DEFAULT NULL,
+  excluded_prefix_length SMALLINT NOT NULL,
+  client_class VARCHAR(128) DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  CONSTRAINT fk_dhcp6_pd_pool_subnet_id FOREIGN KEY (subnet_id) REFERENCES dhcp6_subnet(subnet_id)
+);
+
+CREATE INDEX dhcp6_pd_pool_idx1 ON dhcp6_pd_pool (modification_ts);
+CREATE INDEX dhcp6_pd_pool_idx2 ON dhcp6_pd_pool (subnet_id);
+CREATE TRIGGER dhcp6_pd_pool_modification_ts_update
+  AFTER UPDATE ON dhcp6_pd_pool
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+CREATE TABLE dhcp6_subnet_server (
+  subnet_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (subnet_id, server_id),
+  CONSTRAINT fk_dhcp6_subnet_server_server_id
+    FOREIGN KEY (server_id) REFERENCES dhcp6_server (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp6_subnet_server_subnet_id
+    FOREIGN KEY (subnet_id) REFERENCES dhcp6_subnet (subnet_id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  UNIQUE (subnet_id, server_id)
+);
+CREATE INDEX dhcp6_subnet_server_idx1 ON dhcp6_subnet_server(server_id);
+CREATE INDEX dhcp6_subnet_server_idx2 ON dhcp6_subnet_server(modification_ts);
+CREATE TRIGGER dhcp6_subnet_server_modification_ts_update
+  AFTER UPDATE ON dhcp6_subnet_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Create table for storing global DHCPv6 parameters.
+CREATE TABLE dhcp6_global_parameter (
+  id SERIAL PRIMARY KEY NOT NULL,
+  name VARCHAR(128) NOT NULL,
+  value TEXT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  parameter_type SMALLINT NOT NULL,
+  CONSTRAINT fk_dhcp6_global_parameter_type FOREIGN KEY (parameter_type) REFERENCES parameter_data_type(id)
+);
+
+CREATE INDEX key_dhcp6_global_parameter_idx1 ON dhcp6_global_parameter(modification_ts);
+CREATE INDEX key_dhcp6_global_parameter_idx2 ON dhcp6_global_parameter(name);
+
+CREATE TRIGGER dhcp6_global_parameter_modification_ts_update
+  AFTER UPDATE ON dhcp6_global_parameter
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+CREATE TABLE dhcp6_global_parameter_server (
+  parameter_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (parameter_id, server_id),
+  CONSTRAINT fk_dhcp6_global_parameter_server_parameter_id FOREIGN KEY (parameter_id)
+    REFERENCES dhcp6_global_parameter(id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp6_global_parameter_server_server_id FOREIGN KEY (server_id)
+    REFERENCES dhcp6_server(id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+CREATE INDEX key_dhcp6_global_parameter_server_idx1 ON dhcp6_global_parameter_server(modification_ts);
+CREATE TRIGGER dhcp6_global_parameter_server_modification_ts_update
+  AFTER UPDATE ON dhcp6_global_parameter_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Create a table for storing DHCPv6 options.
+ALTER TABLE dhcp6_options
+  ADD COLUMN shared_network_name VARCHAR(128) DEFAULT NULL,
+  ADD COLUMN pool_id BIGINT DEFAULT NULL,
+  ADD COLUMN pd_pool_id BIGINT DEFAULT NULL,
+  ADD CONSTRAINT fk_dhcp6_options_pd_pool FOREIGN KEY (pd_pool_id)
+    REFERENCES dhcp6_pd_pool(id) ON DELETE CASCADE ON UPDATE CASCADE,
+  ADD CONSTRAINT fk_dhcp6_options_pool FOREIGN KEY (pool_id)
+    REFERENCES dhcp6_pool (id) ON DELETE CASCADE ON UPDATE CASCADE,
+  ADD CONSTRAINT fk_dhcp6_options_shared_network FOREIGN KEY (shared_network_name)
+    REFERENCES dhcp6_shared_network (name) ON DELETE CASCADE ON UPDATE CASCADE;
+
+CREATE TRIGGER dhcp6_options_modification_ts_update
+  AFTER UPDATE ON dhcp6_options
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Now create a table for associating defined options with servers.
+CREATE TABLE dhcp6_options_server (
+  option_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (option_id, server_id),
+  CONSTRAINT fk_dhcp6_options_server_option_id FOREIGN KEY (option_id)
+    REFERENCES dhcp6_options (option_id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp6_options_server_server_id FOREIGN KEY (server_id)
+    REFERENCES dhcp6_server (id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+CREATE INDEX dhcp6_options_server_idx1 ON dhcp6_options_server(server_id);
+CREATE INDEX dhcp6_options_server_idx2 ON dhcp6_options_server(modification_ts);
+CREATE TRIGGER dhcp6_options_server_modification_ts_update
+  AFTER UPDATE ON dhcp6_options_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- This table is for storing IPv6 option definitions
+CREATE TABLE dhcp6_option_def (
+  id SERIAL PRIMARY KEY UNIQUE NOT NULL,
+  code SMALLINT NOT NULL,
+  name VARCHAR(128) NOT NULL,
+  space VARCHAR(128) NOT NULL,
+  type SMALLINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  is_array BOOLEAN NOT NULL,
+  encapsulate VARCHAR(128) NOT NULL,
+  record_types VARCHAR DEFAULT NULL,
+  user_context JSON DEFAULT NULL
+);
+CREATE INDEX dhcp6_option_def_idx1 ON dhcp6_option_def(modification_ts);
+CREATE INDEX dhcp6_option_def_idx2 ON dhcp6_option_def(code, space);
+CREATE TRIGGER dhcp6_option_def_modification_ts_update
+  AFTER UPDATE ON dhcp6_option_def
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- and another table for storing relationship between option definitions and servers.
+CREATE TABLE dhcp6_option_def_server (
+  option_def_id BIGINT NOT NULL REFERENCES dhcp6_option_def (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  server_id BIGINT NOT NULL REFERENCES dhcp6_server (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (option_def_id, server_id)
+);
+CREATE TRIGGER dhcp6_option_def_server_modification_ts_update
+  AFTER UPDATE ON dhcp6_option_def_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Now create two tables for audit revisions...
+CREATE TABLE dhcp6_audit_revision (
+  id SERIAL PRIMARY KEY NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  log_message TEXT DEFAULT NULL,
+  server_id BIGINT DEFAULT NULL
+);
+CREATE TRIGGER dhcp6_audit_revision_modification_ts_update
+  AFTER UPDATE ON dhcp6_audit_revision
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- ... and the DHCPv6 audit itself.
+CREATE TABLE dhcp6_audit (
+  id SERIAL UNIQUE NOT NULL,
+  object_type VARCHAR(256) NOT NULL,
+  object_id BIGINT NOT NULL,
+  modification_type SMALLINT NOT NULL,
+  revision_id BIGINT NOT NULL,
+  CONSTRAINT fk_dhcp6_audit_modification_type FOREIGN KEY (modification_type)
+    REFERENCES modification (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp6_audit_revision FOREIGN KEY (revision_id)
+    REFERENCES dhcp6_audit_revision (id) ON DELETE NO ACTION ON UPDATE CASCADE
+);
+CREATE TRIGGER dhcp6_audit_modification_ts_update
+  AFTER UPDATE ON dhcp6_audit
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+CREATE INDEX dhcp6_audit_idx1 ON dhcp6_audit (modification_type);
+CREATE INDEX dhcp6_audit_idx2 ON dhcp6_audit (revision_id);
+
+-- Create table for DHCPv4 servers
+CREATE TABLE dhcp4_server (
+  id SERIAL PRIMARY KEY NOT NULL,
+  tag VARCHAR(64) NOT NULL,
+  description TEXT DEFAULT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  UNIQUE(tag)
+);
+CREATE INDEX dhcp4_server_modification_ts ON dhcp6_server (modification_ts);
+CREATE TRIGGER dhcp4_server_modification_ts_update
+  AFTER UPDATE ON dhcp4_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+INSERT INTO dhcp4_server (tag, description) VALUES ('all','special type: all servers');
+
+-- Create table for storing global DHCPv4 parameters.
+CREATE TABLE dhcp4_global_parameter (
+  id SERIAL PRIMARY KEY NOT NULL,
+  name VARCHAR(128) NOT NULL,
+  value TEXT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  parameter_type SMALLINT NOT NULL,
+  CONSTRAINT fk_dhcp6_global_parameter_type FOREIGN KEY (parameter_type) REFERENCES parameter_data_type(id)
+);
+CREATE INDEX dhcp4_global_parameter_idx1 ON dhcp4_global_parameter(modification_ts);
+CREATE INDEX dhcp4_global_parameter_idx2 ON dhcp4_global_parameter(name);
+
+CREATE TRIGGER dhcp4_global_parameter_modification_ts_update
+  AFTER UPDATE ON dhcp4_global_parameter
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- and create mapping for the global DHCPv4 parameters mapping to servers
+CREATE TABLE dhcp4_global_parameter_server (
+  parameter_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (parameter_id, server_id),
+  CONSTRAINT fk_dhcp4_global_parameter_server_parameter_id FOREIGN KEY (parameter_id)
+    REFERENCES dhcp4_global_parameter(id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp4_global_parameter_server_server_id FOREIGN KEY (server_id)
+    REFERENCES dhcp4_server(id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+CREATE INDEX key_dhcp4_global_parameter_idx1 ON dhcp4_global_parameter_server(modification_ts);
+CREATE TRIGGER dhcp4_global_parameter_server_modification_ts_update
+  AFTER UPDATE ON dhcp4_global_parameter_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Create a table for storing IPv4 shared networks
+CREATE TABLE dhcp4_shared_network (
+  id SERIAL PRIMARY KEY NOT NULL,
+  name VARCHAR(128) UNIQUE NOT NULL,
+  client_class VARCHAR(128) DEFAULT NULL,
+  interface VARCHAR(128) DEFAULT NULL,
+  match_client_id BOOLEAN DEFAULT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  rebind_timer BIGINT DEFAULT NULL,
+  relay TEXT DEFAULT NULL,
+  renew_timer BIGINT DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  valid_lifetime BIGINT DEFAULT NULL,
+  authoritative BOOLEAN DEFAULT NULL,
+  calculate_tee_times BOOLEAN DEFAULT NULL,
+  t1_percent float DEFAULT NULL,
+  t2_percent float DEFAULT NULL,
+  boot_file_name VARCHAR(128) DEFAULT NULL,
+  next_server inet DEFAULT NULL,   -- let's use type inet
+  server_hostname VARCHAR(64) DEFAULT NULL,
+  min_valid_lifetime BIGINT DEFAULT NULL,
+  max_valid_lifetime BIGINT DEFAULT NULL,
+  ddns_send_updates BOOLEAN DEFAULT NULL,
+  ddns_override_no_update BOOLEAN DEFAULT NULL,
+  ddns_override_client_update BOOLEAN DEFAULT NULL,
+  ddns_replace_client_name INT8 DEFAULT NULL,
+  ddns_generated_prefix VARCHAR(255) DEFAULT NULL,
+  ddns_qualifying_suffix VARCHAR(255) DEFAULT NULL,
+  reservations_global BOOLEAN DEFAULT NULL,
+  reservations_in_subnet BOOLEAN DEFAULT NULL,
+  reservations_out_of_pool BOOLEAN DEFAULT NULL,
+  cache_threshold float DEFAULT NULL,
+  cache_max_age BIGINT DEFAULT NULL,
+  CONSTRAINT fk_ddns_replace_client_name FOREIGN KEY (ddns_replace_client_name)
+    REFERENCES ddns_replace_client_name_types (type)
+);
+
+CREATE UNIQUE INDEX dhcp4_shared_network_idx1 ON dhcp4_shared_network (name);
+CREATE INDEX dhcp4_shared_network_idx2 ON dhcp4_shared_network (modification_ts);
+
+CREATE TRIGGER dhcp4_shared_network_modification_ts_update
+  AFTER UPDATE ON dhcp4_shared_network
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Now we need to create a relationship between defined shared networks and the servers
+CREATE TABLE dhcp4_shared_network_server (
+  shared_network_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (shared_network_id, server_id),
+  CONSTRAINT fk_dhcp4_shared_network_server_server_id FOREIGN KEY (server_id)
+    REFERENCES dhcp4_server (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp4_shared_network_server_shared_network_id FOREIGN KEY (shared_network_id)
+    REFERENCES dhcp4_shared_network (id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+CREATE INDEX dhcp4_shared_network_server_idx1 ON dhcp4_shared_network_server (modification_ts);
+CREATE INDEX dhcp4_shared_network_server_idx2 ON dhcp4_shared_network_server (server_id);
+
+-- Create a list of IPv4 subnets
+CREATE TABLE dhcp4_subnet (
+  subnet_id BIGINT PRIMARY KEY NOT NULL,
+  subnet_prefix VARCHAR(64) UNIQUE NOT NULL,
+  interface_4o6 VARCHAR(128) DEFAULT NULL,
+  interface_id_4o6 VARCHAR(128) DEFAULT NULL,
+  subnet_4o6 VARCHAR(64) DEFAULT NULL,
+  boot_file_name VARCHAR(128) DEFAULT NULL,
+  client_class VARCHAR(128) DEFAULT NULL,
+  interface VARCHAR(128) DEFAULT NULL,
+  match_client_id BOOLEAN DEFAULT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  next_server inet DEFAULT NULL,
+  rebind_timer BIGINT DEFAULT NULL,
+  relay TEXT DEFAULT NULL,
+  renew_timer BIGINT DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  server_hostname VARCHAR(64) DEFAULT NULL,
+  shared_network_name VARCHAR(128) DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  valid_lifetime BIGINT DEFAULT NULL,
+  authoritative BOOLEAN DEFAULT NULL,
+  calculate_tee_times BOOLEAN DEFAULT NULL,
+  t1_percent float DEFAULT NULL,
+  t2_percent float DEFAULT NULL,
+  min_valid_lifetime BIGINT DEFAULT NULL,
+  max_valid_lifetime BIGINT DEFAULT NULL,
+  ddns_send_updates BOOLEAN DEFAULT NULL,
+  ddns_override_no_update BOOLEAN DEFAULT NULL,
+  ddns_override_client_update BOOLEAN DEFAULT NULL,
+  ddns_replace_client_name INT8 DEFAULT NULL,
+  ddns_generated_prefix VARCHAR(255) DEFAULT NULL,
+  ddns_qualifying_suffix VARCHAR(255) DEFAULT NULL,
+  reservations_global BOOLEAN DEFAULT NULL,
+  reservations_in_subnet BOOLEAN DEFAULT NULL,
+  reservations_out_of_pool BOOLEAN DEFAULT NULL,
+  cache_threshold float DEFAULT NULL,
+  cache_max_age BIGINT DEFAULT NULL,
+  CONSTRAINT fk_dhcp4_subnet_shared_network FOREIGN KEY (shared_network_name)
+    REFERENCES dhcp4_shared_network (name) ON DELETE SET NULL ON UPDATE NO ACTION,
+  CONSTRAINT fk_ddns_replace_client_name FOREIGN KEY (ddns_replace_client_name)
+    REFERENCES ddns_replace_client_name_types (type)
+);
+
+CREATE TRIGGER dhcp4_subnet_modification_ts_update
+  AFTER UPDATE ON dhcp4_subnet
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+CREATE INDEX dhcp4_subnet_idx1 ON dhcp4_subnet (modification_ts);
+CREATE INDEX dhcp4_subnet_idx2 ON dhcp4_subnet (shared_network_name);
+
+CREATE TABLE dhcp4_subnet_server (
+  subnet_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (subnet_id, server_id),
+  CONSTRAINT fk_dhcp6_subnet_server_server_id
+    FOREIGN KEY (server_id) REFERENCES dhcp6_server (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp6_subnet_server_subnet_id
+    FOREIGN KEY (subnet_id) REFERENCES dhcp6_subnet (subnet_id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  UNIQUE (subnet_id, server_id)
+);
+CREATE INDEX dhcp4_subnet_server_idx1 ON dhcp4_subnet_server(server_id);
+CREATE INDEX dhcp4_subnet_server_idx2 ON dhcp4_subnet_server(modification_ts);
+CREATE TRIGGER dhcp4_subnet_server_modification_ts_update
+  AFTER UPDATE ON dhcp4_subnet_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Create a table that holds all address pools in IPv4.
+CREATE TABLE dhcp4_pool (
+  id SERIAL PRIMARY KEY NOT NULL,
+  start_address inet NOT NULL,
+  end_address inet NOT NULL,
+  subnet_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  client_class VARCHAR(128) DEFAULT NULL,
+  require_client_classes TEXT DEFAULT NULL,
+  user_context JSON DEFAULT NULL,
+  CONSTRAINT fk_dhcp4_pool_subnet_id FOREIGN KEY (subnet_id) REFERENCES dhcp4_subnet (subnet_id)
+);
+CREATE INDEX dhcp4_pool_idx1 ON dhcp4_pool (modification_ts);
+CREATE INDEX dhcp4_pool_idx2 ON dhcp4_pool (subnet_id);
+
+CREATE TRIGGER dhcp4_pool_modification_ts_update
+  AFTER UPDATE ON dhcp4_pool
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Create a table for storing DHCPv4 options.
+ALTER TABLE dhcp4_options
+  ADD COLUMN shared_network_name VARCHAR(128) DEFAULT NULL,
+  ADD COLUMN pool_id BIGINT DEFAULT NULL,
+  ADD COLUMN modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  ADD CONSTRAINT fk_dhcp4_options_pool FOREIGN KEY (pool_id)
+    REFERENCES dhcp4_pool (id) ON DELETE CASCADE ON UPDATE CASCADE,
+  ADD CONSTRAINT fk_dhcp4_options_shared_network FOREIGN KEY (shared_network_name)
+    REFERENCES dhcp4_shared_network (name) ON DELETE CASCADE ON UPDATE CASCADE;
+
+CREATE TRIGGER dhcp4_options_modification_ts_update
+  AFTER UPDATE ON dhcp4_options
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Now create a table for associating defined v4 options with servers.
+CREATE TABLE dhcp4_options_server (
+  option_id BIGINT NOT NULL,
+  server_id BIGINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (option_id, server_id),
+  CONSTRAINT fk_dhcp4_options_server_option_id FOREIGN KEY (option_id)
+    REFERENCES dhcp4_options (option_id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp4_options_server_server_id FOREIGN KEY (server_id)
+    REFERENCES dhcp4_server (id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+CREATE INDEX dhcp4_options_server_idx1 ON dhcp4_options_server(server_id);
+CREATE INDEX dhcp4_options_server_idx2 ON dhcp4_options_server(modification_ts);
+CREATE TRIGGER dhcp4_options_server_modification_ts_update
+  AFTER UPDATE ON dhcp4_options_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- This table is for storing IPv4 option definitions
+CREATE TABLE dhcp4_option_def (
+  id SERIAL PRIMARY KEY UNIQUE NOT NULL,
+  code SMALLINT NOT NULL,
+  name VARCHAR(128) NOT NULL,
+  space VARCHAR(128) NOT NULL,
+  type SMALLINT NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  is_array BOOLEAN NOT NULL,
+  encapsulate VARCHAR(128) NOT NULL,
+  record_types VARCHAR DEFAULT NULL,
+  user_context JSON DEFAULT NULL
+);
+CREATE INDEX dhcp4_option_def_idx1 ON dhcp4_option_def(modification_ts);
+CREATE INDEX dhcp4_option_def_idx2 ON dhcp4_option_def(code, space);
+CREATE TRIGGER dhcp4_option_def_modification_ts_update
+  AFTER UPDATE ON dhcp4_option_def
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- and another table for storing relationship between option definitions and servers.
+CREATE TABLE dhcp4_option_def_server (
+  option_def_id BIGINT NOT NULL REFERENCES dhcp6_option_def (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  server_id BIGINT NOT NULL REFERENCES dhcp4_server (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (option_def_id, server_id)
+);
+CREATE TRIGGER dhcp4_option_def_server_modification_ts_update
+  AFTER UPDATE ON dhcp4_option_def_server
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- Now create two tables for audit revisions...
+CREATE TABLE dhcp4_audit_revision (
+  id SERIAL PRIMARY KEY NOT NULL,
+  modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  log_message TEXT DEFAULT NULL,
+  server_id BIGINT DEFAULT NULL
+);
+CREATE TRIGGER dhcp4_audit_revision_modification_ts_update
+  AFTER UPDATE ON dhcp4_audit_revision
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+
+-- ... and the DHCPv4 audit itself.
+CREATE TABLE dhcp4_audit (
+  id SERIAL UNIQUE NOT NULL,
+  object_type VARCHAR(256) NOT NULL,
+  object_id BIGINT NOT NULL,
+  modification_type SMALLINT NOT NULL,
+  revision_id BIGINT NOT NULL,
+  CONSTRAINT fk_dhcp4_audit_modification_type FOREIGN KEY (modification_type)
+    REFERENCES modification (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+  CONSTRAINT fk_dhcp4_audit_revision FOREIGN KEY (revision_id)
+    REFERENCES dhcp4_audit_revision (id) ON DELETE NO ACTION ON UPDATE CASCADE
+);
+CREATE TRIGGER dhcp4_audit_modification_ts_update
+  AFTER UPDATE ON dhcp4_audit
+  FOR EACH ROW EXECUTE PROCEDURE modification_ts_update();
+CREATE INDEX dhcp4_audit_idx1 ON dhcp4_audit (modification_type);
+CREATE INDEX dhcp4_audit_idx2 ON dhcp4_audit (revision_id);
+
+-- Stores a TEXT value to a session variable
+-- name name of session variable to set
+-- value TEXT value to store
+CREATE OR REPLACE FUNCTION set_session_value(name text, value TEXT)
+RETURNS VOID
+AS \$\$
+DECLARE
+BEGIN
+    PERFORM set_config(name, value, false);
+    RETURN;
+
+    EXCEPTION
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'set_session_value(%) : value:[%] failed, sqlstate: %', name, value, sqlstate;
+END;\$\$
+LANGUAGE plpgsql;
+
+-- Stores a BIGINT value to a session variable
+-- Note the value converted to TEXT and then stored as Postgresql does
+-- not support any other data type in session variables.
+-- name name of session variable to set
+-- value BIGINT value to store
+CREATE OR REPLACE FUNCTION set_session_value(name text, value BIGINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    PERFORM set_config(name, cast(value as text), false);
+    RETURN;
+
+    EXCEPTION
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'set_session_value(%) : value:[%] failed, sqlstate: %', name, value, sqlstate;
+END;\$\$
+LANGUAGE plpgsql;
+
+-- Stores a BOOLEAN value to a session variable
+-- Note the value converted to TEXT and then stored as Postgresql does
+-- not support any other data type in session variables.
+-- name name of session variable to set
+-- value BOOLEAN value to store
+CREATE OR REPLACE FUNCTION set_session_value(name text, value BOOLEAN)
+RETURNS VOID
+AS \$\$
+BEGIN
+    PERFORM set_config(name, cast(value as text), false);
+    RETURN;
+
+    EXCEPTION
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'set_session_value(%) : value:[%] failed, sqlstate: %', name, value, sqlstate;
+END;\$\$
+LANGUAGE plpgsql;
+
+-- Fetches a text value from the session configuration.
+-- param name name of the session variable to fetch
+-- If the name is not found it returns NULL.
+-- Postgresql allows you to store custom session values
+-- but throws an exception if they have not first been
+-- set.  This allows us to be a bit more graceful.
+CREATE OR REPLACE FUNCTION get_session_value(name TEXT)
+RETURNS TEXT
+AS \$\$
+DECLARE
+    text_value TEXT := '';
+BEGIN
+    text_value = current_setting(name);
+    RETURN(text_value);
+
+    EXCEPTION
+    WHEN undefined_object THEN
+        -- Variable has not been initialized so return NULL
+        RETURN NULL;
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'get_session_value(%, TEXT) failed, sqlstate: %', name, sqlstate;
+END;\$\$
+LANGUAGE plpgsql;
+
+-- Fetches an BIGINT value from the session configuration.
+-- param name name of the session variable to fetch
+-- If the name is not found it returns zero.
+CREATE OR REPLACE FUNCTION get_session_big_int(name text)
+RETURNS BIGINT
+AS \$\$
+DECLARE
+    int_value BIGINT := 0;
+    text_value TEXT := '';
+BEGIN
+    text_value = get_session_value(name);
+    IF text_value is NULL or text_value = '' THEN
+        RETURN(0);
+    END IF;
+
+    int_value = cast(text_value as BIGINT);
+    RETURN(int_value);
+
+    EXCEPTION
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'get_session_big_int(%) failed - text:[%] , sqlstate: %', name, text_value, sqlstate;
+
+END;\$\$
+LANGUAGE plpgsql;
+
+-- Fetches an BOOLEAN value from the session configuration.
+-- param name name of the session variable to fetch
+-- If the name is not found it returns zero.
+CREATE OR REPLACE FUNCTION get_session_boolean(name text)
+RETURNS BOOLEAN
+AS \$\$
+DECLARE
+    bool_value BOOLEAN := false;
+    text_value TEXT := '';
+BEGIN
+    text_value = get_session_value(name);
+    IF text_value is NULL or text_value = '' THEN
+        RETURN(false);
+    END IF;
+
+    bool_value = cast(text_value as BOOLEAN);
+    RETURN(bool_value);
+
+    EXCEPTION
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'get_session_boolean(%) failed - text:[%] , sqlstate: %', name, text_value, sqlstate;
+
+END;\$\$
+LANGUAGE plpgsql;
+
+-- -----------------------------------------------------
+-- Stored procedure which creates a new entry in the
+-- dhcp4_audit_revision table and sets appropriate session
+-- variables to be used while creating the audit entries
+-- by triggers. This procedure should be called at the
+-- beginning of a transaction which modifies configuration
+-- data in the database, e.g. when new subnet is added.
+--
+-- Parameters:
+-- - audit_ts timestamp to be associated with the audit
+--   revision.
+-- - server_tag is used to retrieve the server_id which
+--   associates the changes applied with the particular
+--   server or all servers.
+-- - audit_log_message is a log message associates with
+--   the audit revision.
+-- - cascade_transaction is assigned to a session
+--   variable which is used in some triggers to determine
+--   if the audit entry should be created for them or
+--   not. Specifically, this is used when DHCP options
+--   are inserted, updated or deleted. If such modification
+--   is a part of the larger change (e.g. change in the
+--   subnet the options belong to) the dedicated audit
+--   entry for options must not be created. On the other
+--   hand, if the global option is being added, the
+--   audit entry for the option must be created because
+--   it is the sole object modified in that case.
+--   Session variable disable_audit is used to disable
+--   the procedure when wiping the database during
+--   unit tests.  This avoids issues with revision_id
+--   being null.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createAuditRevisionDHCP4(audit_ts TIMESTAMP WITH TIME ZONE,
+                                                    server_tag VARCHAR(64),
+                                                    audit_log_message TEXT,
+                                                    cascade_transaction BOOLEAN)
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    disable_audit BOOLEAN := false;
+    audit_revision_id BIGINT;
+    srv_id BIGINT;
+BEGIN
+    -- Fetch session value for disable_audit.
+    disable_audit := get_session_boolean('kea.disable_audit');
+    IF disable_audit = false THEN
+        SELECT id INTO srv_id FROM dhcp4_server WHERE tag = server_tag;
+        INSERT INTO dhcp4_audit_revision (modification_ts, server_id, log_message)
+            VALUES (audit_ts, srv_id, audit_log_message) returning id INTO audit_revision_id;
+
+        -- Update pertinent session variables.
+        PERFORM set_session_value('kea.audit_revision_id', audit_revision_id);
+        PERFORM set_session_value('kea.cascade_transaction', cascade_transaction);
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- -----------------------------------------------------
+-- Stored procedure which creates a new entry in the
+-- dhcp4_audit table. It should be called from the
+-- triggers of the tables where the config modifications
+-- are applied. The audit_revision_id variable contains
+-- the revision id to be placed in the audit entries.
+--
+-- The following parameters are passed to this procedure:
+-- - object_type_val: name of the table to be associated
+--   with the applied changes.
+-- - object_id_val: identifier of the modified object in
+--   that table.
+-- - modification_type_val: string value indicating the
+--   type of the change, i.e. 'create', 'update' or
+--   'delete'.
+--   Session variable disable_audit is used to disable
+--   the procedure when wiping the database during
+--   unit tests.  This avoids issues with revision_id
+--   being null.
+-- ----------------------------------------------------
+CREATE OR REPLACE FUNCTION createAuditEntryDHCP4(object_type_val VARCHAR(256),
+                                                 object_id_val BIGINT,
+                                                 modification_type_val VARCHAR(32))
+RETURNS VOID
+LANGUAGE plpgsql
+as \$\$
+DECLARE
+    audit_revision_id BIGINT;
+    disable_audit BOOLEAN := false;
+BEGIN
+    -- Fetch session value for disable_audit.
+    disable_audit := get_session_boolean('kea.disable_audit');
+
+    IF disable_audit IS NULL OR disable_audit = false THEN
+        -- Fetch session value most recently created audit_revision_id.
+        audit_revision_id := get_session_big_int('kea.audit_revision_id');
+        INSERT INTO dhcp4_audit (object_type, object_id, modification_type, revision_id)
+            VALUES (object_type_val, object_id_val,
+                (SELECT id FROM modification WHERE modification_type = modification_type_val),
+                 audit_revision_id);
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- -----------------------------------------------------------------------
+-- Create a table holding the DHCPv4 client classes. Most table
+-- columns map directly to respective client class properties in
+-- Kea configuration. The depend_on_known_directly column is
+-- explicitly set in an insert or update statement to indicate
+-- if the client class directly depends on KNOWN or UNKNOWN
+-- built-in classes. A caller should determine it by evaluating
+-- a test expression before inserting or updating the client
+-- class in the database. The nullable follow_class_name column
+-- can be used for positioning the inserted or updated client
+-- class within the class hierarchy. Set this column value to
+-- an existing class name, after which this class should be
+-- placed in the class hierarchy. See dhcp4_client_class_order
+-- description for the details of how classes are ordered.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp4_client_class (
+    id SERIAL PRIMARY KEY NOT NULL,
+    name VARCHAR(128) UNIQUE NOT NULL,
+    test TEXT,
+    next_server INET DEFAULT NULL,
+    server_hostname VARCHAR(128) DEFAULT NULL,
+    boot_file_name VARCHAR(512) DEFAULT NULL,
+    only_if_required BOOLEAN NOT NULL DEFAULT false,
+    valid_lifetime BIGINT DEFAULT NULL,
+    min_valid_lifetime BIGINT DEFAULT NULL,
+    max_valid_lifetime BIGINT DEFAULT NULL,
+    depend_on_known_directly BOOLEAN NOT NULL DEFAULT false,
+    follow_class_name VARCHAR(128) DEFAULT NULL,
+    modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE INDEX key_dhcp4_client_class_modification_ts on dhcp4_client_class (modification_ts);
+
+-- -----------------------------------------------------------------------
+-- Create a table for ordering client classes and holding information
+-- about indirect dependencies on KNOWN/UKNOWN built-in client classes.
+-- Each class in the dhcp4_client_class table has a corresponding row
+-- in the dhcp4_client_class_order table. A caller should not modify
+-- the contents of this table. Its entries are automatically created
+-- upon inserting or updating client classes in the dhcp4_client_classes
+-- using triggers. The order_index designates the position of the client
+-- class within the class hierarchy. If the follow_class_name value of
+-- the dhcp4_client_class table is set to NULL, the client class is
+-- appended at the end of the hierarchy. The assigned order_index
+-- value for that class is set to a maximum current value + 1.
+-- If the follow_client_class specifies a name of an existing class,
+-- the generated order_index is set to an id of that class + 1, and
+-- the order_index values of the later classes are incremented by 1.
+-- The depend_on_known_indirectly column holds a boolean value indicating
+-- whether the given class depends on KNOWN/UKNOWN built-in classes
+-- via other classes, i.e. it depends on classes that directly or
+-- indirectly depend on these built-ins. This value is auto-generated
+-- by a trigger on the dhcp4_client_class_dependency table.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp4_client_class_order (
+    class_id BIGINT PRIMARY KEY NOT NULL,
+    order_index BIGINT NOT NULL,
+    depend_on_known_indirectly BOOLEAN NOT NULL DEFAULT false,
+    CONSTRAINT fk_dhcp4_client_class_order_class_id FOREIGN KEY (class_id)
+        REFERENCES dhcp4_client_class (id) ON DELETE CASCADE
+);
+
+CREATE INDEX key_dhcp4_client_class_order_index on dhcp4_client_class_order (order_index);
+
+-- -----------------------------------------------------------------------
+-- Stored procedure positioning an inserted or updated client class
+-- within the class hierarchy, depending on the value of the
+-- follow_class_name parameter.
+--
+-- Parameters:
+-- - id id of the positioned class,
+-- - follow_class_name name of the class after which this class should be
+--   positioned within the class hierarchy.
+-- - old_follow_class_name previous name of the class after which this
+--   class was positioned within the class hierarchy.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION setClientClass4Order(id BIGINT,
+                                                new_follow_class_name VARCHAR(128),
+                                                old_follow_class_name VARCHAR(128))
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    -- Used to fetch class's current value for depend_on_known_indirectly
+    l_depend_on_known_indirectly BIGINT := 0;
+
+    -- Optionally set if the follow_class_name column value is specified.
+    follow_class_index BIGINT;
+BEGIN
+    -- Fetch the class's current value of depend_on_known_indirectly.
+    SELECT depend_on_known_indirectly INTO l_depend_on_known_indirectly
+        FROM dhcp4_client_class_order WHERE id = class_id;
+
+    -- Save it to the current session for use elsewhere during this transaction.
+    -- Note this does not work prior to Postgres 9.2 unless the variables are
+    -- defined in postgresql.conf. I think for now we put up with CB not supported
+    -- prior to 9.2 or we tell people how to edit the conf file.
+    PERFORM set_session_value('kea.depend_on_known_indirectly', l_depend_on_known_indirectly);
+
+    -- Bail if the class is updated without re-positioning.
+    IF(
+       l_depend_on_known_indirectly IS NOT NULL AND
+       ((new_follow_class_name IS NULL AND old_follow_class_name IS NULL) OR
+        (new_follow_class_name = old_follow_class_name))
+    ) THEN
+        -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+        -- whenever the dhcp4_client_class record is updated. Such update may include
+        -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+        -- This value will be later adjusted when dependencies are inserted.
+        -- TKM should we update the session value also or is it moot?
+        UPDATE dhcp4_client_class_order SET depend_on_known_indirectly = false
+            WHERE class_id = id;
+        RETURN;
+    END IF;
+
+    IF new_follow_class_name IS NOT NULL THEN
+        -- Get the position of the class after which the new class should be added.
+        SELECT o.order_index INTO follow_class_index
+            FROM dhcp4_client_class AS c
+            INNER JOIN dhcp4_client_class_order AS o
+                ON c.id = o.class_id
+            WHERE c.name = new_follow_class_name;
+
+        IF follow_class_index IS NULL THEN
+            -- The class with a name specified with new_follow_class_name does
+            -- not exist.
+            RAISE EXCEPTION 'Class %s does not exist.', new_follow_class_name
+                USING ERRCODE = 'sql_routine_exception';
+        END IF;
+
+        -- We need to place the new class at the position of follow_class_index + 1.
+        -- There may be a class at this position already.
+        IF EXISTS(SELECT * FROM dhcp4_client_class_order WHERE order_index = follow_class_index + 1) THEN
+            -- There is a class at this position already. Let's move all classes
+            -- starting from this position by one to create a spot for the new
+            -- class.
+            UPDATE dhcp4_client_class_order
+                SET order_index = order_index + 1
+            WHERE order_index >= follow_class_index + 1;
+            -- TKM postgresql doesn't like order by here, does it matter?
+            -- ORDER BY order_index DESC;
+        END IF;
+
+    ELSE
+        -- A caller did not specify the new_follow_class_name value. Let's append the
+        -- new class at the end of the hierarchy.
+        SELECT MAX(order_index) INTO follow_class_index FROM dhcp4_client_class_order;
+        IF follow_class_index IS NULL THEN
+            -- Apparently, there are no classes. Let's start from 0.
+            follow_class_index = 0;
+        END IF;
+    END IF;
+
+    -- Check if moving the class doesn't break dependent classes.
+    IF EXISTS(
+        SELECT 1 FROM dhcp4_client_class_dependency AS d
+            INNER JOIN dhcp4_client_class_order AS o
+                ON d.class_id = o.class_id
+            WHERE d.dependency_id = id AND o.order_index < follow_class_index + 1
+        LIMIT 1
+    ) THEN
+        RAISE EXCEPTION 'Unable to move class with id %s because it would break its dependencies', id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+    -- whenever the dhcp4_client_class record is updated. Such update may include
+    -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+    -- This value will be later adjusted when dependencies are inserted.
+    -- ON CONFLICT required 9.5 or later
+    UPDATE dhcp4_client_class_order
+        SET order_index = follow_class_index + 1,
+            depend_on_known_indirectly = l_depend_on_known_indirectly
+        WHERE class_id = id;
+    IF FOUND THEN
+        RETURN;
+    END IF;
+
+    INSERT INTO  dhcp4_client_class_order(class_id, order_index, depend_on_known_indirectly)
+        VALUES (id, follow_class_index + 1, 0);
+    RETURN;
+END;\$\$;
+
+-- -----------------------------------------------------------------------
+-- Trigger procedure to position an inserted class within the class hierarchy
+-- and create audit.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp4_client_class_AINS() RETURNS trigger AS \$dhcp4_client_class_AINS\$
+BEGIN
+    PERFORM setClientClass4Order(NEW.id, NEW.follow_class_name, NULL);
+    PERFORM createAuditEntryDHCP4('dhcp4_client_class', NEW.id, 'create');
+    RETURN NULL;
+END;
+\$dhcp4_client_class_AINS\$
+LANGUAGE plpgsql;
+
+-- Create dhcp4_client_class insert trigger
+CREATE TRIGGER dhcp4_client_class_AINS
+    AFTER INSERT ON dhcp4_client_class
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_client_class_AINS();
+
+-- -----------------------------------------------------------------------
+-- Trigger to position an updated class within the class hierarchy,
+-- create audit and remember the direct dependency on the
+-- KNOWN/UNKNOWN built-in classes before the class update.
+-- When updating a client class, it is very important to ensure that
+-- its dependency on KNOWN or UNKNOWN built-in client classes is not
+-- changed. It is because there may be other classes that depend on
+-- these built-ins via this class. Changing the dependency would break
+-- the chain of dependencies for other classes. Here, we store the
+-- information about the dependency in the session variables. Their
+-- values will be compared with the new dependencies after an update.
+-- If they change, an error will be signaled.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp4_client_class_AUPD() RETURNS trigger AS \$dhcp4_client_class_AUPD\$
+BEGIN
+    PERFORM set_session_value('kea.depend_on_known_directly', OLD.depend_on_known_directly);
+    PERFORM set_session_value('kea.client_class_id', NEW.id);
+    PERFORM setClientClass4Order(NEW.id, NEW.follow_class_name, OLD.follow_class_name);
+    PERFORM createAuditEntryDHCP4('dhcp4_client_class', NEW.id, 'update');
+    RETURN NULL;
+END;
+\$dhcp4_client_class_AUPD\$
+LANGUAGE plpgsql;
+
+-- Create dhcp4_client_class update insert trigger
+CREATE TRIGGER dhcp4_client_class_AUPD
+    AFTER UPDATE ON dhcp4_client_class
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_client_class_AUPD();
+
+-- -----------------------------------------------------------------------
+-- Trigger procedure to create the audit entry for client class delete.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp4_client_class_ADEL() RETURNS trigger AS \$dhcp4_client_class_ADEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_client_class', OLD.id, 'delete');
+    RETURN NULL;
+END;
+\$dhcp4_client_class_ADEL\$
+LANGUAGE plpgsql;
+
+-- Create dhcp4_client_class delete trigger
+CREATE TRIGGER dhcp4_client_class_ADEL
+    AFTER DELETE ON dhcp4_client_class
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_client_class_ADEL();
+
+-- -----------------------------------------------------------------------
+-- Create a table associating client classes stored in the
+-- dhcp4_client_class table with their dependencies. There is
+-- an M:N relationship between these tables. Each class may have
+-- many dependencies (created using member operator in test expression),
+-- and each class may be a dependency for many other classes. A caller
+-- is responsible for inserting dependencies for a class after inserting
+-- or updating it in the dhcp4_client_class table. A caller should
+-- delete all existing dependencies for an updated client class, evaluate
+-- test expression to discover new dependencies (in case test expression
+-- has changed), and insert new dependencies to this table.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp4_client_class_dependency (
+    class_id BIGINT PRIMARY KEY NOT NULL,
+    dependency_id BIGINT NOT NULL,
+
+    CONSTRAINT dhcp4_client_class_class_id FOREIGN KEY (class_id)
+        REFERENCES dhcp4_client_class (id) ON DELETE CASCADE,
+    CONSTRAINT dhcp4_client_class_dependency_id FOREIGN KEY (dependency_id)
+        REFERENCES dhcp4_client_class (id)
+);
+
+CREATE INDEX dhcp4_client_class_dependency_id_idx on dhcp4_client_class_dependency (dependency_id);
+
+-- -----------------------------------------------------------------------
+-- Stored procedure verifying if class dependency is met. It includes
+-- checking if referenced classes exist, are associated with the same
+-- server or all servers, and are defined before the class specified with
+-- class_id.
+--
+-- Parameters:
+-- - p_class_id id client class,
+-- - p_dependency_id id of the dependency.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION checkDHCPv4ClientClassDependency(p_class_id BIGINT,
+                                                            p_dependency_id BIGINT)
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    class_index BIGINT;
+    dependency_index BIGINT;
+BEGIN
+    -- We could check the same with a constraint but later in this
+    -- trigger we use this value to verify if the dependencies are
+    -- met.
+    IF p_class_id IS NULL THEN
+        RAISE EXCEPTION 'Client class id must not be NULL.'
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    IF p_dependency_id IS NULL THEN
+        RAISE EXCEPTION 'Class dependency id must not be NULL.'
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Dependencies on self make no sense.
+    IF p_class_id = p_dependency_id THEN
+        RAISE EXCEPTION 'Client class must not have dependency on self.'
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Check position of our class in the hierarchy.
+    SELECT o.order_index INTO class_index FROM dhcp4_client_class AS c
+        INNER JOIN dhcp4_client_class_order AS o ON c.id = o.class_id
+        WHERE c.id = p_class_id;
+
+    IF class_index IS NULL THEN
+        RAISE EXCEPTION 'Client class with id % does not exist.', p_class_id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Check position of the dependency.
+    SELECT o.order_index INTO dependency_index FROM dhcp4_client_class AS c
+        INNER JOIN dhcp4_client_class_order AS o ON c.id = o.class_id
+        WHERE c.id = p_dependency_id;
+
+    IF dependency_index IS NULL THEN
+        RAISE EXCEPTION 'Dependency class with id % does not exist.', p_dependency_id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- The dependency must not be later than our class.
+    IF dependency_index > class_index THEN
+        RAISE EXCEPTION
+            'Client class with id % must not depend on class defined later with id %',
+            p_class_id, p_dependency_id USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Check if all servers associated with the new class have dependent
+    -- classes configured. This catches the cases that class A belongs to
+    -- server1 and depends on class B which belongs only to server 2.
+    -- It is fine if the class B belongs to all servers in this case.
+    -- Make a SELECT on the dhcp4_client_class_server table to gather
+    -- all servers to which the class belongs. LEFT JOIN it with the
+    -- same table, selecting all records matching the dependency class
+    -- and the servers to which the new class belongs. If there are
+    -- any NULL records joined it implies that some dependencies are
+    -- not met (didn't find a dependency for at least one server).
+    IF EXISTS(
+        SELECT 1 FROM dhcp4_client_class_server AS t1
+            LEFT JOIN dhcp4_client_class_server AS t2
+                ON t2.class_id = p_dependency_id AND (t2.server_id = 1 OR t2.server_id = t1.server_id)
+        WHERE t1.class_id = p_class_id AND t2.server_id IS NULL
+        LIMIT 1
+    ) THEN
+        RAISE EXCEPTION 'Unmet dependencies for client class with id %', class_id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- -----------------------------------------------------------------------
+-- Trigger verifying if class dependency is met. It includes checking
+-- if referenced classes exist, are associated with the same server
+-- or all servers, and are defined before the class specified with
+-- class_id.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp4_client_class_check_dependency_BINS()
+    RETURNS trigger AS \$dhcp4_client_class_check_dependency_BINS\$
+BEGIN
+    PERFORM checkDHCPv4ClientClassDependency(NEW.class_id, NEW.dependency_id);
+    RETURN NULL;
+END;
+\$dhcp4_client_class_check_dependency_BINS\$
+LANGUAGE plpgsql;
+
+-- Create dhcp4_client_class_check_dependency_BINS before insert trigger.
+CREATE TRIGGER dhcp4_client_class_check_dependency_BINS
+    BEFORE INSERT ON dhcp4_client_class_dependency
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_client_class_check_dependency_BINS();
+
+-- -----------------------------------------------------------------------
+-- Stored procedure setting client class indirect dependency on KNOWN or
+-- UNKNOWN built-in classes by checking this flag for the client classes
+-- on which it depends.
+--
+-- Parameters:
+-- - client_class_id id of the client class which dependency is set,
+-- - dependency_id id of the client class on which the given class depends.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION updateDHCPv4ClientClassKnownDependency(client_class_id BIGINT,
+                                                                  dependency_id BIGINT)
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    dependency BOOLEAN;
+BEGIN
+    -- Check if the dependency class references KNOWN/UNKNOWN.
+    SELECT depend_on_known_directly INTO dependency FROM dhcp4_client_class
+        WHERE id = dependency_id;
+
+    -- If it doesn't, check if the dependency references KNOWN/UNKNOWN
+    -- indirectly (via other classes).
+    IF dependency = false THEN
+        SELECT depend_on_known_indirectly INTO dependency FROM dhcp4_client_class_order
+            WHERE class_id = dependency_id;
+    END IF;
+
+    IF dependency = true THEN
+        UPDATE dhcp4_client_class_order
+            SET depend_on_known_indirectly = true
+        WHERE class_id = client_class_id;
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- -----------------------------------------------------------------------
+-- Trigger setting client class indirect dependency on KNOWN or UNKNOWN
+-- built-in classes by checking this flag for the client classes on which
+-- it depends.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp4_client_class_dependency_AINS()
+    RETURNS TRIGGER AS \$dhcp4_client_class_dependency_AINS\$
+BEGIN
+    PERFORM updateDHCPv4ClientClassKnownDependency(NEW.class_id, NEW.dependency_id);
+    RETURN NULL;
+END;
+\$dhcp4_client_class_dependency_AINS\$
+LANGUAGE plpgsql;
+
+-- Create dhcp4_client_class_check_dependency_AINS after insert trigger.
+CREATE TRIGGER dhcp4_client_class_dependency_AINS
+    AFTER INSERT ON dhcp4_client_class_dependency
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_client_class_dependency_AINS();
+
+-- -----------------------------------------------------------------------
+-- Stored procedure to be executed before committing a transaction
+-- updating a DHCPv4 client class. It verifies if the class dependency on
+-- KNOWN or UNKNOWN built-in classes has changed as a result of the
+-- update. It signals an error if it has changed and there is at least
+-- one class depending on this class.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION checkDHCPv4ClientClassKnownDependencyChange()
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    depended BOOLEAN := false;
+    depends BOOLEAN := false;
+    client_class_id BIGINT;
+    depend_on_known_directly BOOLEAN;
+    depend_on_known_indirectly BOOLEAN;
+BEGIN
+
+    -- Session variables are set upon a client class update.
+    client_class_id := get_session_big_int('kea.client_class_id');
+    IF client_class_id IS NOT NULL THEN
+        -- Check if any of the classes depend on this class. If not,
+        -- it is ok to change the dependency on KNOWN/UNKNOWN.
+        IF EXISTS(
+            SELECT 1 FROM dhcp4_client_class_dependency
+            WHERE dependency_id = client_class_id LIMIT 1
+        ) THEN
+            -- Using the session variables, determine whether the client class
+            -- depended on KNOWN/UNKNOWN before the update.
+            depend_on_known_directly := get_session_boolean('kea.depend_on_known_directly');
+            depend_on_known_indirectly := get_session_boolean('kea.depend_on_known_indirectly');
+            IF depend_on_known_directly = true OR depend_on_known_indirectly = true THEN
+                SET depended = true;
+            END IF;
+
+            -- Check if the client class depends on KNOWN/UNKNOWN after the update.
+            SELECT depend_on_known_directly INTO depends FROM dhcp4_client_class
+                WHERE id = client_class_id;
+
+            -- If it doesn't depend directly, check indirect dependencies.
+            IF depends = false THEN
+                SELECT depend_on_known_indirectly INTO depends FROM dhcp4_client_class_order
+                    WHERE class_id = client_class_id;
+            END IF;
+
+            -- The resulting dependency on KNOWN/UNKNOWN must not change.
+            IF depended <> depends THEN
+                RAISE EXCEPTION 'Class dependency on KNOWN/UNKNOWN built-in classes must not change.'
+                    USING ERRCODE = 'sql_routine_exception';
+            END IF;
+        END IF;
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- -----------------------------------------------------------------------
+-- Create table matching DHCPv4 classes with the servers.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp4_client_class_server (
+    class_id BIGINT NOT NULL,
+    server_id BIGINT NOT NULL,
+    modification_ts  TIMESTAMP WITH TIME ZONE NULL DEFAULT NULL,
+    PRIMARY KEY (class_id,server_id),
+    CONSTRAINT fk_dhcp4_client_class_class_id FOREIGN KEY (class_id)
+        REFERENCES dhcp4_client_class (id)
+        ON DELETE CASCADE,
+    CONSTRAINT fk_dhcp4_client_class_server_id FOREIGN KEY (server_id)
+        REFERENCES dhcp4_server (id)
+);
+
+CREATE INDEX fk_dhcp4_client_class_server_id ON dhcp4_client_class_server (server_id);
+
+-- -----------------------------------------------------
+-- Stored procedure which creates a new entry in the
+-- dhcp6_audit_revision table and sets appropriate session
+-- variables to be used while creating the audit entries
+-- by triggers. This procedure should be called at the
+-- beginning of a transaction which modifies configuration
+-- data in the database, e.g. when new subnet is added.
+--
+-- Parameters:
+-- - audit_ts timestamp to be associated with the audit
+--   revision.
+-- - server_tag is used to retrieve the server_id which
+--   associates the changes applied with the particular
+--   server or all servers.
+-- - audit_log_message is a log message associates with
+--   the audit revision.
+-- - cascade_transaction is assigned to a session
+--   variable which is used in some triggers to determine
+--   if the audit entry should be created for them or
+--   not. Specifically, this is used when DHCP options
+--   are inserted, updated or deleted. If such modification
+--   is a part of the larger change (e.g. change in the
+--   subnet the options belong to) the dedicated audit
+--   entry for options must not be created. On the other
+--   hand, if the global option is being added, the
+--   audit entry for the option must be created because
+--   it is the sole object modified in that case.
+--   Session variable disable_audit is used to disable
+--   the procedure when wiping the database during
+--   unit tests.  This avoids issues with revision_id
+--   being null.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createAuditRevisionDHCP6(audit_ts TIMESTAMP WITH TIME ZONE,
+                                                    server_tag VARCHAR(64),
+                                                    audit_log_message TEXT,
+                                                    cascade_transaction BOOLEAN)
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    disable_audit BOOLEAN := false;
+    audit_revision_id BIGINT;
+    srv_id BIGINT;
+BEGIN
+    -- Fetch session value for disable_audit.
+    disable_audit := get_session_boolean('kea.disable_audit');
+    IF disable_audit = false THEN
+        SELECT id INTO srv_id FROM dhcp6_server WHERE tag = server_tag;
+        INSERT INTO dhcp6_audit_revision (modification_ts, server_id, log_message)
+            VALUES (audit_ts, srv_id, audit_log_message) returning id INTO audit_revision_id;
+
+        -- Update pertinent session variables.
+        PERFORM set_session_value('kea.audit_revision_id', audit_revision_id);
+        PERFORM set_session_value('kea.cascade_transaction', cascade_transaction);
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- -----------------------------------------------------
+-- Stored procedure which creates a new entry in the
+-- dhcp6_audit table. It should be called from the
+-- triggers of the tables where the config modifications
+-- are applied. The audit_revision_id variable contains
+-- the revision id to be placed in the audit entries.
+--
+-- The following parameters are passed to this procedure:
+-- - object_type_val: name of the table to be associated
+--   with the applied changes.
+-- - object_id_val: identifier of the modified object in
+--   that table.
+-- - modification_type_val: string value indicating the
+--   type of the change, i.e. 'create', 'update' or
+--   'delete'.
+--   Session variable disable_audit is used to disable
+--   the procedure when wiping the database during
+--   unit tests.  This avoids issues with revision_id
+--   being null.
+-- ----------------------------------------------------
+CREATE OR REPLACE FUNCTION createAuditEntryDHCP6(object_type_val VARCHAR(256),
+                                                 object_id_val BIGINT,
+                                                 modification_type_val VARCHAR(32))
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    audit_revision_id BIGINT;
+    disable_audit BOOLEAN := false;
+BEGIN
+    -- Fetch session value for disable_audit.
+    disable_audit := get_session_boolean('kea.disable_audit');
+    IF disable_audit = false THEN
+        -- Fetch session value most recently created audit_revision_id.
+        audit_revision_id := get_session_big_int('kea.audit_revision_id');
+        INSERT INTO dhcp6_audit (object_type, object_id, modification_type, revision_id)
+            VALUES (object_type_val, object_id_val,
+                (SELECT id FROM modification WHERE modification_type = modification_type_val),
+                 audit_revision_id);
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- -----------------------------------------------------------------------
+-- Create a table holding the DHCPv6 client classes. Most table
+-- columns map directly to respective client class properties in
+-- Kea configuration. The depend_on_known_directly column is
+-- explicitly set in an insert or update statement to indicate
+-- if the client class directly depends on KNOWN or UNKNOWN
+-- built-in classes. A caller should determine it by evaluating
+-- a test expression before inserting or updating the client
+-- class in the database. The nullable follow_class_name column
+-- can be used for positioning the inserted or updated client
+-- class within the class hierarchy. Set this column value to
+-- an existing class name, after which this class should be
+-- placed in the class hierarchy. See dhcp6_client_class_order
+-- description for the details of how classes are ordered.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp6_client_class (
+    id SERIAL PRIMARY KEY NOT NULL,
+    name VARCHAR(128) UNIQUE NOT NULL,
+    test TEXT,
+    only_if_required BOOLEAN NOT NULL DEFAULT false,
+    valid_lifetime BIGINT DEFAULT NULL,
+    min_valid_lifetime BIGINT DEFAULT NULL,
+    max_valid_lifetime BIGINT DEFAULT NULL,
+    depend_on_known_directly BOOLEAN NOT NULL DEFAULT false,
+    follow_class_name VARCHAR(128) DEFAULT NULL,
+    modification_ts TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE INDEX key_dhcp6_client_class_modification_ts on dhcp6_client_class (modification_ts);
+
+-- -----------------------------------------------------------------------
+-- Create a table for ordering client classes and holding information
+-- about indirect dependencies on KNOWN/UKNOWN built-in client classes.
+-- Each class in the dhcp6_client_class table has a corresponding row
+-- in the dhcp6_client_class_order table. A caller should not modify
+-- the contents of this table. Its entries are automatically created
+-- upon inserting or updating client classes in the dhcp6_client_classes
+-- using triggers. The order_index designates the position of the client
+-- class within the class hierarchy. If the follow_class_name value of
+-- the dhcp6_client_class table is set to NULL, the client class is
+-- appended at the end of the hierarchy. The assigned order_index
+-- value for that class is set to a maximum current value + 1.
+-- If the follow_client_class specifies a name of an existing class,
+-- the generated order_index is set to an id of that class + 1, and
+-- the order_index values of the later classes are incremented by 1.
+-- The depend_on_known_indirectly column holds a boolean value indicating
+-- whether the given class depends on KNOWN/UKNOWN built-in classes
+-- via other classes, i.e. it depends on classes that directly or
+-- indirectly depend on these built-ins. This value is auto-generated
+-- by a trigger on the dhcp6_client_class_dependency table.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp6_client_class_order (
+    class_id BIGINT PRIMARY KEY NOT NULL,
+    order_index BIGINT NOT NULL,
+    depend_on_known_indirectly BOOLEAN NOT NULL DEFAULT false,
+    CONSTRAINT fk_dhcp6_client_class_order_class_id FOREIGN KEY (class_id)
+        REFERENCES dhcp6_client_class (id) ON DELETE CASCADE
+);
+
+CREATE INDEX key_dhcp6_client_class_order_index on dhcp6_client_class_order (order_index);
+
+-- -----------------------------------------------------------------------
+-- Stored procedure positioning an inserted or updated client class
+-- within the class hierarchy, depending on the value of the
+-- new_follow_class_name parameter.
+--
+-- Parameters:
+-- - id id of the positioned class,
+-- - new_follow_class_name name of the class after which this class should be
+--   positioned within the class hierarchy.
+-- - old_follow_class_name previous name of the class after which this
+--   class was positioned within the class hierarchy.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION setClientClass6Order(id BIGINT,
+                                                new_follow_class_name VARCHAR(128),
+                                                old_follow_class_name VARCHAR(128))
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    -- Used to fetch class's current value for depend_on_known_indirectly
+    l_depend_on_known_indirectly BIGINT := 0;
+
+    -- Optionally set if the follow_class_name column value is specified.
+    follow_class_index BIGINT;
+BEGIN
+    -- Fetch the class's current value of depend_on_known_indirectly.
+    SELECT depend_on_known_indirectly INTO l_depend_on_known_indirectly
+        FROM dhcp6_client_class_order WHERE id = class_id;
+
+    -- Save it to the current session for use elsewhere during this transaction.
+    -- Note this does not work prior to Postgres 9.2 unless the variables are
+    -- defined in postgresql.conf. I think for now we put up with CB not supported
+    -- prior to 9.2 or we tell people how to edit the conf file.
+    PERFORM set_session_value('kea.depend_on_known_indirectly', l_depend_on_known_indirectly);
+
+    -- Bail if the class is updated without re-positioning.
+    IF(
+       l_depend_on_known_indirectly IS NOT NULL AND
+       ((new_follow_class_name IS NULL AND old_follow_class_name IS NULL) OR
+        (new_follow_class_name = old_follow_class_name))
+    ) THEN
+        -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+        -- whenever the dhcp6_client_class record is updated. Such update may include
+        -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+        -- This value will be later adjusted when dependencies are inserted.
+        -- TKM should we update the session value also or is it moot?
+        UPDATE dhcp6_client_class_order SET depend_on_known_indirectly = false
+            WHERE class_id = id;
+        RETURN;
+    END IF;
+
+    IF new_follow_class_name IS NOT NULL THEN
+        -- Get the position of the class after which the new class should be added.
+        SELECT o.order_index INTO follow_class_index
+            FROM dhcp6_client_class AS c
+            INNER JOIN dhcp6_client_class_order AS o
+                ON c.id = o.class_id
+            WHERE c.name = new_follow_class_name;
+
+        IF follow_class_index IS NULL THEN
+            -- The class with a name specified with new_follow_class_name does
+            -- not exist.
+            RAISE EXCEPTION 'Class %s does not exist.', new_follow_class_name
+                USING ERRCODE = 'sql_routine_exception';
+        END IF;
+
+        -- We need to place the new class at the position of follow_class_index + 1.
+        -- There may be a class at this position already.
+        IF EXISTS(SELECT * FROM dhcp6_client_class_order WHERE order_index = follow_class_index + 1) THEN
+            -- There is a class at this position already. Let's move all classes
+            -- starting from this position by one to create a spot for the new
+            -- class.
+            UPDATE dhcp6_client_class_order
+                SET order_index = order_index + 1
+            WHERE order_index >= follow_class_index + 1;
+            -- TKM postgresql doesn't like order by here, does it matter?
+            -- ORDER BY order_index DESC;
+        END IF;
+
+    ELSE
+        -- A caller did not specify the new_follow_class_name value. Let's append the
+        -- new class at the end of the hierarchy.
+        SELECT MAX(order_index) INTO follow_class_index FROM dhcp6_client_class_order;
+        IF follow_class_index IS NULL THEN
+            -- Apparently, there are no classes. Let's start from 0.
+            follow_class_index = 0;
+        END IF;
+    END IF;
+
+    -- Check if moving the class doesn't break dependent classes.
+    IF EXISTS(
+        SELECT 1 FROM dhcp6_client_class_dependency AS d
+            INNER JOIN dhcp6_client_class_order AS o
+                ON d.class_id = o.class_id
+            WHERE d.dependency_id = id AND o.order_index < follow_class_index + 1
+        LIMIT 1
+    ) THEN
+        RAISE EXCEPTION 'Unable to move class with id %s because it would break its dependencies', id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+    -- whenever the dhcp6_client_class record is updated. Such update may include
+    -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+    -- This value will be later adjusted when dependencies are inserted.
+    -- TKM - note that ON CONFLICT requires PostgreSQL 9.5 or later.
+    UPDATE dhcp6_client_class_order
+        SET order_index = follow_class_index + 1,
+            depend_on_known_indirectly = l_depend_on_known_indirectly
+        WHERE class_id = id;
+    IF FOUND THEN
+        RETURN;
+    END IF;
+
+    INSERT INTO  dhcp6_client_class_order(class_id, order_index, depend_on_known_indirectly)
+        VALUES (id, follow_class_index + 1, 0);
+    RETURN;
+END;\$\$;
+
+-- -----------------------------------------------------------------------
+-- Trigger procedure to position an inserted class within the class hierarchy
+-- and create audit.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp6_client_class_AINS() RETURNS trigger AS \$dhcp6_client_class_AINS\$
+BEGIN
+    PERFORM setClientClass6Order(NEW.id, NEW.follow_class_name, NULL);
+    PERFORM createAuditEntryDHCP6('dhcp6_client_class', NEW.id, 'create');
+    RETURN NULL;
+END;
+\$dhcp6_client_class_AINS\$
+LANGUAGE plpgsql;
+
+-- Create dhcp6_client_class insert trigger
+CREATE TRIGGER dhcp6_client_class_AINS
+    AFTER INSERT ON dhcp6_client_class
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_client_class_AINS();
+
+-- -----------------------------------------------------------------------
+-- Trigger to position an updated class within the class hierarchy,
+-- create audit and remember the direct dependency on the
+-- KNOWN/UNKNOWN built-in classes before the class update.
+-- When updating a client class, it is very important to ensure that
+-- its dependency on KNOWN or UNKNOWN built-in client classes is not
+-- changed. It is because there may be other classes that depend on
+-- these built-ins via this class. Changing the dependency would break
+-- the chain of dependencies for other classes. Here, we store the
+-- information about the dependency in the session variables. Their
+-- values will be compared with the new dependencies after an update.
+-- If they change, an error will be signaled.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp6_client_class_AUPD() RETURNS trigger AS \$dhcp6_client_class_AUPD\$
+BEGIN
+    PERFORM set_session_value('kea.depend_on_known_directly', OLD.depend_on_known_directly);
+    PERFORM set_session_value('kea.client_class_id', NEW.id);
+    PERFORM setClientClass6Order(NEW.id, NEW.follow_class_name, OLD.follow_class_name);
+    PERFORM createAuditEntryDHCP6('dhcp6_client_class', NEW.id, 'update');
+    RETURN NULL;
+END;
+\$dhcp6_client_class_AUPD\$
+LANGUAGE plpgsql;
+
+-- Create dhcp6_client_class update insert trigger
+CREATE TRIGGER dhcp6_client_class_AUPD
+    AFTER UPDATE ON dhcp6_client_class
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_client_class_AUPD();
+
+-- -----------------------------------------------------------------------
+-- Trigger procedure to create the audit entry for client class delete.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp6_client_class_ADEL() RETURNS trigger AS \$dhcp6_client_class_ADEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_client_class', OLD.id, 'delete');
+    RETURN NULL;
+END;
+\$dhcp6_client_class_ADEL\$
+LANGUAGE plpgsql;
+
+-- Create dhcp6_client_class delete trigger
+CREATE TRIGGER dhcp6_client_class_ADEL
+    AFTER DELETE ON dhcp6_client_class
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_client_class_ADEL();
+
+-- -----------------------------------------------------------------------
+-- Create a table associating client classes stored in the
+-- dhcp6_client_class table with their dependencies. There is
+-- an M:N relationship between these tables. Each class may have
+-- many dependencies (created using member operator in test expression),
+-- and each class may be a dependency for many other classes. A caller
+-- is responsible for inserting dependencies for a class after inserting
+-- or updating it in the dhcp6_client_class table. A caller should
+-- delete all existing dependencies for an updated client class, evaluate
+-- test expression to discover new dependencies (in case test expression
+-- has changed), and insert new dependencies to this table.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp6_client_class_dependency (
+    class_id BIGINT PRIMARY KEY NOT NULL,
+    dependency_id BIGINT NOT NULL,
+
+    CONSTRAINT dhcp6_client_class_class_id FOREIGN KEY (class_id)
+        REFERENCES dhcp6_client_class (id) ON DELETE CASCADE,
+    CONSTRAINT dhcp6_client_class_dependency_id FOREIGN KEY (dependency_id)
+        REFERENCES dhcp6_client_class (id)
+);
+
+CREATE INDEX dhcp6_client_class_dependency_id_idx on dhcp6_client_class_dependency (dependency_id);
+
+-- -----------------------------------------------------------------------
+-- Stored procedure verifying if class dependency is met. It includes
+-- checking if referenced classes exist, are associated with the same
+-- server or all servers, and are defined before the class specified with
+-- class_id.
+--
+-- Parameters:
+-- - p_class_id id client class,
+-- - p_dependency_id id of the dependency.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION checkDHCPv6ClientClassDependency(p_class_id BIGINT,
+                                                            p_dependency_id BIGINT)
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    class_index BIGINT;
+    dependency_index BIGINT;
+BEGIN
+    -- We could check the same with a constraint but later in this
+    -- trigger we use this value to verify if the dependencies are
+    -- met.
+    IF p_class_id IS NULL THEN
+        RAISE EXCEPTION 'Client class id must not be NULL.'
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    IF p_dependency_id IS NULL THEN
+        RAISE EXCEPTION 'Class dependency id must not be NULL.'
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Dependencies on self make no sense.
+    IF p_class_id = p_dependency_id THEN
+        RAISE EXCEPTION 'Client class must not have dependency on self.'
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Check position of our class in the hierarchy.
+    SELECT o.order_index INTO class_index FROM dhcp6_client_class AS c
+        INNER JOIN dhcp6_client_class_order AS o ON c.id = o.class_id
+        WHERE c.id = p_class_id;
+
+    IF class_index IS NULL THEN
+        RAISE EXCEPTION 'Client class with id % does not exist.', p_class_id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Check position of the dependency.
+    SELECT o.order_index INTO dependency_index FROM dhcp6_client_class AS c
+        INNER JOIN dhcp6_client_class_order AS o ON c.id = o.class_id
+        WHERE c.id = p_dependency_id;
+
+    IF dependency_index IS NULL THEN
+        RAISE EXCEPTION 'Dependency class with id % does not exist.', p_dependency_id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- The dependency must not be later than our class.
+    IF dependency_index > class_index THEN
+        RAISE EXCEPTION
+            'Client class with id % must not depend on class defined later with id %',
+            p_class_id, p_dependency_id USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- Check if all servers associated with the new class have dependent
+    -- classes configured. This catches the cases that class A belongs to
+    -- server1 and depends on class B which belongs only to server 2.
+    -- It is fine if the class B belongs to all servers in this case.
+    -- Make a SELECT on the dhcp6_client_class_server table to gather
+    -- all servers to which the class belongs. LEFT JOIN it with the
+    -- same table, selecting all records matching the dependency class
+    -- and the servers to which the new class belongs. If there are
+    -- any NULL records joined it implies that some dependencies are
+    -- not met (didn't find a dependency for at least one server).
+    IF EXISTS(
+        SELECT 1 FROM dhcp6_client_class_server AS t1
+            LEFT JOIN dhcp6_client_class_server AS t2
+                ON t2.class_id = p_dependency_id AND (t2.server_id = 1 OR t2.server_id = t1.server_id)
+        WHERE t1.class_id = p_class_id AND t2.server_id IS NULL
+        LIMIT 1
+    ) THEN
+        RAISE EXCEPTION 'Unmet dependencies for client class with id %', p_class_id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- -----------------------------------------------------------------------
+-- Trigger verifying if class dependency is met. It includes checking
+-- if referenced classes exist, are associated with the same server
+-- or all servers, and are defined before the class specified with
+-- class_id.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp6_client_class_check_dependency_BINS()
+    RETURNS trigger AS \$dhcp6_client_class_check_dependency_BINS\$
+BEGIN
+    PERFORM checkDHCPv6ClientClassDependency(NEW.class_id, NEW.dependency_id);
+    RETURN NULL;
+END;
+\$dhcp6_client_class_check_dependency_BINS\$
+LANGUAGE plpgsql;
+
+-- Create dhcp6_client_class_check_dependency_BINS before insert trigger.
+CREATE TRIGGER dhcp6_client_class_check_dependency_BINS
+    BEFORE INSERT ON dhcp6_client_class_dependency
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_client_class_check_dependency_BINS();
+
+-- -----------------------------------------------------------------------
+-- Stored procedure setting client class indirect dependency on KNOWN or
+-- UNKNOWN built-in classes by checking this flag for the client classes
+-- on which it depends.
+--
+-- Parameters:
+-- - client_class_id id of the client class which dependency is set,
+-- - dependency_id id of the client class on which the given class depends.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION updateDHCPv6ClientClassKnownDependency(client_class_id BIGINT,
+                                                                  dependency_id BIGINT)
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    dependency BOOLEAN;
+BEGIN
+    -- Check if the dependency class references KNOWN/UNKNOWN.
+    SELECT depend_on_known_directly INTO dependency FROM dhcp6_client_class
+        WHERE id = dependency_id;
+
+    -- If it doesn't, check if the dependency references KNOWN/UNKNOWN
+    -- indirectly (via other classes).
+    IF dependency = false THEN
+        SELECT depend_on_known_indirectly INTO dependency FROM dhcp6_client_class_order
+            WHERE class_id = dependency_id;
+    END IF;
+
+    IF dependency = true THEN
+        UPDATE dhcp6_client_class_order
+            SET depend_on_known_indirectly = true
+        WHERE class_id = client_class_id;
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- -----------------------------------------------------------------------
+-- Trigger setting client class indirect dependency on KNOWN or UNKNOWN
+-- built-in classes by checking this flag for the client classes on which
+-- it depends.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp6_client_class_dependency_AINS()
+    RETURNS TRIGGER AS \$dhcp6_client_class_dependency_AINS\$
+BEGIN
+    PERFORM updateDHCPv6ClientClassKnownDependency(NEW.class_id, NEW.dependency_id);
+    RETURN NULL;
+END;
+\$dhcp6_client_class_dependency_AINS\$
+LANGUAGE plpgsql;
+
+-- Create dhcp6_client_class_check_dependency_AINS after insert trigger.
+CREATE TRIGGER dhcp6_client_class_dependency_AINS
+    AFTER INSERT ON dhcp6_client_class_dependency
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_client_class_dependency_AINS();
+
+-- -----------------------------------------------------------------------
+-- Stored procedure to be executed before committing a transaction
+-- updating a DHCPv6 client class. It verifies if the class dependency on
+-- KNOWN or UNKNOWN built-in classes has changed as a result of the
+-- update. It signals an error if it has changed and there is at least
+-- one class depending on this class.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION checkDHCPv6ClientClassKnownDependencyChange()
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    depended BOOLEAN := false;
+    depends BOOLEAN := false;
+    client_class_id BIGINT;
+    depend_on_known_directly BOOLEAN;
+    depend_on_known_indirectly BOOLEAN;
+BEGIN
+
+    -- Session variables are set upon a client class update.
+    client_class_id := get_session_big_int('kea.client_class_id');
+    IF client_class_id IS NOT NULL THEN
+        -- Check if any of the classes depend on this class. If not,
+        -- it is ok to change the dependency on KNOWN/UNKNOWN.
+        IF EXISTS(
+            SELECT 1 FROM dhcp6_client_class_dependency
+            WHERE dependency_id = client_class_id LIMIT 1
+        ) THEN
+            -- Using the session variables, determine whether the client class
+            -- depended on KNOWN/UNKNOWN before the update.
+            depend_on_known_directly := get_session_boolean('kea.depend_on_known_directly');
+            depend_on_known_indirectly := get_session_boolean('kea.depend_on_known_indirectly');
+            IF depend_on_known_directly = true OR depend_on_known_indirectly = true THEN
+                SET depended = true;
+            END IF;
+
+            -- Check if the client class depends on KNOWN/UNKNOWN after the update.
+            SELECT depend_on_known_directly INTO depends FROM dhcp6_client_class
+                WHERE id = client_class_id;
+
+            -- If it doesn't depend directly, check indirect dependencies.
+            IF depends = false THEN
+                SELECT depend_on_known_indirectly INTO depends FROM dhcp6_client_class_order
+                    WHERE class_id = client_class_id;
+            END IF;
+
+            -- The resulting dependency on KNOWN/UNKNOWN must not change.
+            IF depended <> depends THEN
+                RAISE EXCEPTION 'Class dependency on KNOWN/UNKNOWN built-in classes must not change.'
+                    USING ERRCODE = 'sql_routine_exception';
+            END IF;
+        END IF;
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- -----------------------------------------------------------------------
+-- Create table matching DHCPv6 classes with the servers.
+-- -----------------------------------------------------------------------
+CREATE TABLE IF NOT EXISTS dhcp6_client_class_server (
+    class_id BIGINT NOT NULL,
+    server_id BIGINT NOT NULL,
+    modification_ts  TIMESTAMP WITH TIME ZONE NULL DEFAULT NULL,
+    PRIMARY KEY (class_id,server_id),
+    CONSTRAINT fk_dhcp6_client_class_class_id FOREIGN KEY (class_id)
+        REFERENCES dhcp6_client_class (id)
+        ON DELETE CASCADE,
+    CONSTRAINT fk_dhcp6_client_class_server_id FOREIGN KEY (server_id)
+        REFERENCES dhcp6_server (id)
+);
+
+CREATE INDEX fk_dhcp6_client_class_server_id ON dhcp6_client_class_server (server_id);
+
+-- Trigger function for dhcp4_pool_BDEL called BEFORE DELETE on dhcp4_pool
+-- It removes pool specific options upon removal of the pool.
+CREATE OR REPLACE FUNCTION func_dhcp4_pool_BDEL() RETURNS TRIGGER AS \$dhcp4_pool_BDEL\$
+BEGIN
+    DELETE FROM dhcp4_options WHERE scope_id = 5 AND pool_id = OLD.id;
+    RETURN OLD;
+END;
+\$dhcp4_pool_BDEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_pool_BDEL
+    BEFORE DELETE ON dhcp4_pool
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_pool_BDEL();
+
+-- Trigger function for dhcp6_pool_BDEL called BEFORE DELETE on dhcp6_pool
+-- It removes pool specific options upon removal of the pool.
+CREATE OR REPLACE FUNCTION func_dhcp6_pool_BDEL() RETURNS TRIGGER AS \$dhcp6_pool_BDEL\$
+BEGIN
+    DELETE FROM dhcp6_options WHERE scope_id = 5 AND pool_id = OLD.id;
+    RETURN OLD;
+END;
+\$dhcp6_pool_BDEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_pool_BDEL
+    BEFORE DELETE ON dhcp6_pool
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_pool_BDEL();
+
+-- Trigger function for dhcp4_global_parameter_AINS called AFTER INSERT on dhcp4_global_parameter
+CREATE OR REPLACE FUNCTION func_dhcp4_global_parameter_AINS() RETURNS TRIGGER AS \$dhcp4_global_parameter_AINS\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_global_parameter', NEW.id, 'create');
+    RETURN NULL;
+END;
+\$dhcp4_global_parameter_AINS\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_global_parameter_AINS
+    AFTER INSERT ON dhcp4_global_parameter
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_global_parameter_AINS();
+
+-- Trigger function for dhcp4_global_parameter_AUPD called AFTER UPDATE on dhcp4_global_parameter
+CREATE OR REPLACE FUNCTION func_dhcp4_global_parameter_AUPD() RETURNS TRIGGER AS \$dhcp4_global_parameter_AUPD\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_global_parameter', NEW.id, 'update');
+    RETURN NULL;
+END;
+\$dhcp4_global_parameter_AUPD\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_global_parameter_AUPD
+    AFTER UPDATE ON dhcp4_global_parameter
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_global_parameter_AUPD();
+
+-- Trigger function for dhcp4_global_parameter_ADEL called AFTER DELETE on dhcp4_global_parameter
+CREATE OR REPLACE FUNCTION func_dhcp4_global_parameter_ADEL() RETURNS TRIGGER AS \$dhcp4_global_parameter_ADEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_global_parameter', OLD.id, 'delete');
+    RETURN NULL;
+END;
+\$dhcp4_global_parameter_ADEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_global_parameter_ADEL
+    AFTER DELETE ON dhcp4_global_parameter
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_global_parameter_ADEL();
+
+-- Trigger function for dhcp4_subnet_AINS called AFTER INSERT on dhcp4_subnet
+CREATE OR REPLACE FUNCTION func_dhcp4_subnet_AINS() RETURNS TRIGGER AS \$dhcp4_subnet_AINS\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_subnet', NEW.subnet_id, 'create');
+    RETURN NULL;
+END;
+\$dhcp4_subnet_AINS\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_subnet_AINS
+    AFTER INSERT ON dhcp4_subnet
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_subnet_AINS();
+
+-- Trigger function for dhcp4_subnet_AUPD called AFTER UPDATE on dhcp4_subnet
+CREATE OR REPLACE FUNCTION func_dhcp4_subnet_AUPD() RETURNS TRIGGER AS \$dhcp4_subnet_AUPD\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_subnet', NEW.subnet_id, 'update');
+    RETURN NULL;
+END;
+\$dhcp4_subnet_AUPD\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_subnet_AUPD
+    AFTER UPDATE ON dhcp4_subnet
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_subnet_AUPD();
+
+-- Trigger function for dhcp4_shared_network_AINS called AFTER INSERT on dhcp4_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp4_shared_network_AINS() RETURNS TRIGGER AS \$dhcp4_shared_network_AINS\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_shared_network', NEW.id, 'create');
+    RETURN NULL;
+END;
+\$dhcp4_shared_network_AINS\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_shared_network_AINS
+    AFTER INSERT ON dhcp4_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_shared_network_AINS();
+
+-- Trigger function for dhcp4_shared_network_AUPD called AFTER UPDATE on dhcp4_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp4_shared_network_AUPD() RETURNS TRIGGER AS \$dhcp4_shared_network_AUPD\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_shared_network', NEW.id, 'update');
+    RETURN NULL;
+END;
+\$dhcp4_shared_network_AUPD\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_shared_network_AUPD
+    AFTER UPDATE ON dhcp4_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_shared_network_AUPD();
+
+-- Trigger function for dhcp4_shared_network_ADEL called AFTER DELETE on dhcp4_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp4_shared_network_ADEL() RETURNS TRIGGER AS \$dhcp4_shared_network_ADEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_shared_network', OLD.id, 'delete');
+    RETURN NULL;
+END;
+\$dhcp4_shared_network_ADEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_shared_network_ADEL
+    AFTER DELETE ON dhcp4_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_shared_network_ADEL();
+
+-- Trigger function for dhcp4_option_def_AINS called AFTER INSERT on dhcp4_option_def
+CREATE OR REPLACE FUNCTION func_dhcp4_option_def_AINS() RETURNS TRIGGER AS \$dhcp4_option_def_AINS\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_option_def', NEW.id, 'create');
+    RETURN NULL;
+END;
+\$dhcp4_option_def_AINS\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_option_def_AINS
+    AFTER INSERT ON dhcp4_option_def
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_option_def_AINS();
+
+-- Trigger function for dhcp4_option_def_AUPD called AFTER UPDATE on dhcp4_option_def
+CREATE OR REPLACE FUNCTION func_dhcp4_option_def_AUPD() RETURNS TRIGGER AS \$dhcp4_option_def_AUPD\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_option_def', NEW.id, 'update');
+    RETURN NULL;
+END;
+\$dhcp4_option_def_AUPD\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_option_def_AUPD
+    AFTER UPDATE ON dhcp4_option_def
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_option_def_AUPD();
+
+-- Trigger function for dhcp4_option_def_ADEL called AFTER DELETE on dhcp4_option_def
+CREATE OR REPLACE FUNCTION func_dhcp4_option_def_ADEL() RETURNS TRIGGER AS \$dhcp4_option_def_ADEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_option_def', OLD.id, 'delete');
+    RETURN NULL;
+END;
+\$dhcp4_option_def_ADEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_option_def_ADEL
+    AFTER DELETE ON dhcp4_option_def
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_option_def_ADEL();
+
+-- -----------------------------------------------------
+--
+-- Stored procedure which updates modification timestamp of
+-- a parent object when an option is modified.
+--
+-- The following parameters are passed to the procedure:
+-- - modification_type: 'create', 'update' or 'delete'
+-- - scope_id: identifier of the option scope, e.g.
+--   global, subnet specific etc.
+-- - option_id: identifier of the option.
+-- - p_subnet_id: identifier of the subnet if the option
+--   belongs to the subnet.
+-- - host_id: identifier of the host if the option
+-- - belongs to the host.
+-- - network_name: shared network name if the option
+--   belongs to the shared network.
+-- - pool_id: identifier of the pool if the option
+--   belongs to the pool.
+-- - p_modification_ts: modification timestamp of the
+--   option.
+--   Some arguments are prefixed with "p_" to avoid ambiguity
+--   with column names in SQL statements. PostgreSQL does not
+--   allow table aliases to be used with column names in update
+--   set expressions.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createOptionAuditDHCP4(modification_type VARCHAR,
+                                                  scope_id SMALLINT,
+                                                  option_id INT,
+                                                  p_subnet_id BIGINT,
+                                                  host_id INT,
+                                                  network_name VARCHAR,
+                                                  pool_id BIGINT,
+                                                  p_modification_ts TIMESTAMP WITH TIME ZONE)
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    -- These variables will hold shared network id and subnet id that
+    -- we will select.
+    snid VARCHAR(128);
+    sid BIGINT;
+    cascade_transaction BOOLEAN := true;
+    ct TEXT;
+BEGIN
+    -- Cascade transaction flag is set to true to prevent creation of
+    -- the audit entries for the options when the options are
+    -- created as part of the parent object creation or update.
+    -- For example: when the option is added as part of the subnet
+    -- addition, the cascade transaction flag is equal to true. If
+    -- the option is added into the existing subnet the cascade
+    -- transaction is equal to false. Note that depending on the option
+    -- scope the audit entry will contain the object_type value
+    -- of the parent object to cause the server to replace the
+    -- entire subnet. The only case when the object_type will be
+    -- set to 'dhcp4_options' is when a global option is added.
+    -- Global options do not have the owner.
+
+    cascade_transaction := get_session_boolean('kea.cascade_transaction');
+    IF cascade_transaction = false THEN
+        -- todo: host manager hasn't been updated to use audit
+        -- mechanisms so ignore host specific options for now.
+        IF scope_id = 0 THEN
+            -- If a global option is added or modified, create audit
+            -- entry for the 'dhcp4_options' table.
+            PERFORM createAuditEntryDHCP4('dhcp4_options', option_id, modification_type);
+        ELSEIF scope_id = 1 THEN
+            -- If subnet specific option is added or modified, update
+            -- the modification timestamp of this subnet to allow the
+            -- servers to refresh the subnet information. This will
+            -- also result in creating an audit entry for this subnet.
+            UPDATE dhcp4_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = p_subnet_id;
+        ELSEIF scope_id = 4 THEN
+            -- If shared network specific option is added or modified,
+            -- update the modification timestamp of this shared network
+            -- to allow the servers to refresh the shared network
+            -- information. This will also result in creating an
+            -- audit entry for this shared network.
+           SELECT id INTO snid FROM dhcp4_shared_network WHERE name = network_name LIMIT 1;
+           UPDATE dhcp4_shared_network SET modification_ts = p_modification_ts
+                WHERE id = snid;
+        ELSEIF scope_id = 5 THEN
+            -- If pool specific option is added or modified, update
+            -- the modification timestamp of the owning subnet.
+            SELECT dhcp4_pool.subnet_id INTO sid FROM dhcp4_pool WHERE id = pool_id;
+            UPDATE dhcp4_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        END IF;
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- Trigger function for dhcp4_options_AINS called AFTER INSERT on dhcp4_options
+CREATE OR REPLACE FUNCTION func_dhcp4_options_AINS() RETURNS TRIGGER AS \$dhcp4_options_AINS\$
+BEGIN
+    PERFORM createOptionAuditDHCP4('create', NEW.scope_id, NEW.option_id, NEW.dhcp4_subnet_id,
+                                   NEW.host_id, NEW.shared_network_name, NEW.pool_id,
+                                   NEW.modification_ts);
+    RETURN NULL;
+END;
+\$dhcp4_options_AINS\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_options_AINS
+    AFTER INSERT ON dhcp4_options
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_options_AINS();
+
+-- Trigger function for dhcp4_options_AUPD called AFTER UPDATE on dhcp4_options
+CREATE OR REPLACE FUNCTION func_dhcp4_options_AUPD() RETURNS TRIGGER AS \$dhcp4_options_AUPD\$
+BEGIN
+    PERFORM createOptionAuditDHCP4('update', NEW.scope_id, NEW.option_id, NEW.dhcp4_subnet_id,
+                                   NEW.host_id, NEW.shared_network_name, NEW.pool_id,
+                                   NEW.modification_ts);
+    RETURN NULL;
+END;
+\$dhcp4_options_AUPD\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_options_AUPD
+    AFTER UPDATE ON dhcp4_options
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_options_AUPD();
+
+-- Trigger function for dhcp4_options_ADEL called AFTER DELETE on dhcp4_options
+CREATE OR REPLACE FUNCTION func_dhcp4_options_ADEL() RETURNS TRIGGER AS \$dhcp4_options_ADEL\$
+BEGIN
+    PERFORM createOptionAuditDHCP4('delete', OLD.scope_id, OLD.option_id, OLD.dhcp4_subnet_id,
+                                   OLD.host_id, OLD.shared_network_name, OLD.pool_id,
+                                   NOW());
+    RETURN NULL;
+END;
+\$dhcp4_options_ADEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_options_ADEL
+    AFTER DELETE ON dhcp4_options
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_options_ADEL();
+
+-- Trigger function for dhcp6_global_parameter_AINS called AFTER INSERT on dhcp6_global_parameter
+CREATE OR REPLACE FUNCTION func_dhcp6_global_parameter_AINS() RETURNS TRIGGER AS \$dhcp6_global_parameter_AINS\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_global_parameter', NEW.id, 'create');
+    RETURN NULL;
+END;
+\$dhcp6_global_parameter_AINS\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_global_parameter_AINS
+    AFTER INSERT ON dhcp6_global_parameter
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_global_parameter_AINS();
+
+-- Trigger function for dhcp6_global_parameter_AUPD called AFTER UPDATE on dhcp6_global_parameter
+CREATE OR REPLACE FUNCTION func_dhcp6_global_parameter_AUPD() RETURNS TRIGGER AS \$dhcp6_global_parameter_AUPD\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_global_parameter', NEW.id, 'update');
+    RETURN NULL;
+END;
+\$dhcp6_global_parameter_AUPD\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_global_parameter_AUPD
+    AFTER UPDATE ON dhcp6_global_parameter
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_global_parameter_AUPD();
+
+-- Trigger function for dhcp6_global_parameter_ADEL called AFTER DELETE on dhcp6_global_parameter
+CREATE OR REPLACE FUNCTION func_dhcp6_global_parameter_ADEL() RETURNS TRIGGER AS \$dhcp6_global_parameter_ADEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_global_parameter', OLD.id, 'delete');
+    RETURN NULL;
+END;
+\$dhcp6_global_parameter_ADEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_global_parameter_ADEL
+    AFTER DELETE ON dhcp6_global_parameter
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_global_parameter_ADEL();
+
+-- Trigger function for dhcp6_subnet_AINS called AFTER INSERT on dhcp6_subnet
+CREATE OR REPLACE FUNCTION func_dhcp6_subnet_AINS() RETURNS TRIGGER AS \$dhcp6_subnet_AINS\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_subnet', NEW.subnet_id, 'create');
+    RETURN NULL;
+END;
+\$dhcp6_subnet_AINS\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_subnet_AINS
+    AFTER INSERT ON dhcp6_subnet
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_subnet_AINS();
+
+-- Trigger function for dhcp6_subnet_AUPD called AFTER UPDATE on dhcp6_subnet
+CREATE OR REPLACE FUNCTION func_dhcp6_subnet_AUPD() RETURNS TRIGGER AS \$dhcp6_subnet_AUPD\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_subnet', NEW.subnet_id, 'update');
+    RETURN NULL;
+END;
+\$dhcp6_subnet_AUPD\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_subnet_AUPD
+    AFTER UPDATE ON dhcp6_subnet
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_subnet_AUPD();
+
+-- Trigger function for dhcp6_shared_network_AINS called AFTER INSERT on dhcp6_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp6_shared_network_AINS() RETURNS TRIGGER AS \$dhcp6_shared_network_AINS\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_shared_network', NEW.id, 'create');
+    RETURN NULL;
+END;
+\$dhcp6_shared_network_AINS\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_shared_network_AINS
+    AFTER INSERT ON dhcp6_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_shared_network_AINS();
+
+-- Trigger function for dhcp6_shared_network_AUPD called AFTER UPDATE on dhcp6_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp6_shared_network_AUPD() RETURNS TRIGGER AS \$dhcp6_shared_network_AUPD\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_shared_network', NEW.id, 'update');
+    RETURN NULL;
+END;
+\$dhcp6_shared_network_AUPD\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_shared_network_AUPD
+    AFTER UPDATE ON dhcp6_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_shared_network_AUPD();
+
+-- Trigger function for dhcp6_shared_network_ADEL called AFTER DELETE on dhcp6_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp6_shared_network_ADEL() RETURNS TRIGGER AS \$dhcp6_shared_network_ADEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_shared_network', OLD.id, 'delete');
+    RETURN NULL;
+END;
+\$dhcp6_shared_network_ADEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_shared_network_ADEL
+    AFTER DELETE ON dhcp6_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_shared_network_ADEL();
+
+-- Trigger function for dhcp6_option_def_AINS called AFTER INSERT on dhcp6_option_def
+CREATE OR REPLACE FUNCTION func_dhcp6_option_def_AINS() RETURNS TRIGGER AS \$dhcp6_option_def_AINS\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_option_def', NEW.id, 'create');
+    RETURN NULL;
+END;
+\$dhcp6_option_def_AINS\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_option_def_AINS
+    AFTER INSERT ON dhcp6_option_def
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_option_def_AINS();
+
+-- Trigger function for dhcp6_option_def_AUPD called AFTER UPDATE on dhcp6_option_def
+CREATE OR REPLACE FUNCTION func_dhcp6_option_def_AUPD() RETURNS TRIGGER AS \$dhcp6_option_def_AUPD\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_option_def', NEW.id, 'update');
+    RETURN NULL;
+END;
+\$dhcp6_option_def_AUPD\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_option_def_AUPD
+    AFTER UPDATE ON dhcp6_option_def
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_option_def_AUPD();
+
+-- Trigger function for dhcp6_option_def_ADEL called AFTER DELETE on dhcp6_option_def
+CREATE OR REPLACE FUNCTION func_dhcp6_option_def_ADEL() RETURNS TRIGGER AS \$dhcp6_option_def_ADEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_option_def', OLD.id, 'delete');
+    RETURN NULL;
+END;
+\$dhcp6_option_def_ADEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_option_def_ADEL
+    AFTER DELETE ON dhcp6_option_def
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_option_def_ADEL();
+
+-- - pool_id: identifier of the pool if the option
+--   belongs to the pool.
+-- - pd_pool_id: identifier of the pool if the option
+--   belongs to the pd pool.
+-- - modification_ts: modification timestamp of the
+--   option.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createOptionAuditDHCP6(modification_type VARCHAR(32),
+                                                  scope_id SMALLINT,
+                                                  option_id INT,
+                                                  subnet_id BIGINT,
+                                                  host_id INT,
+                                                  network_name VARCHAR(128),
+                                                  pool_id BIGINT,
+                                                  pd_pool_id BIGINT,
+                                                  modification_ts TIMESTAMP WITH TIME ZONE)
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    -- These variables will hold shared network id and subnet id that
+    -- we will select.
+    snid VARCHAR(128);
+    sid BIGINT;
+    cascade_transaction BOOLEAN := false;
+
+BEGIN
+    -- Cascade transaction flag is set to true to prevent creation of
+    -- the audit entries for the options when the options are
+    -- created as part of the parent object creation or update.
+    -- For example: when the option is added as part of the subnet
+    -- addition, the cascade transaction flag is equal to true. If
+    -- the option is added into the existing subnet the cascade
+    -- transaction is equal to false. Note that depending on the option
+    -- scope the audit entry will contain the object_type value
+    -- of the parent object to cause the server to replace the
+    -- entire subnet. The only case when the object_type will be
+    -- set to 'dhcp6_options' is when a global option is added.
+    -- Global options do not have the owner.
+    cascade_transaction := get_session_boolean('kea.cascade_transaction');
+    IF cascade_transaction = false THEN
+        -- todo: host manager hasn't been updated to use audit
+        -- mechanisms so ignore host specific options for now.
+        IF scope_id = 0 THEN
+            -- If a global option is added or modified, create audit
+            -- entry for the 'dhcp6_options' table.
+            PERFORM createAuditEntryDHCP6('dhcp6_options', option_id, modification_type);
+        ELSEIF scope_id = 1 THEN
+            -- If subnet specific option is added or modified, create
+            -- audit entry for the entire subnet, which indicates that
+            -- it should be treated as the subnet update.
+            PERFORM createAuditEntryDHCP6('dhcp6_subnet', subnet_id, 'update');
+        ELSEIF scope_id = 4 THEN
+            -- If shared network specific option is added or modified,
+            -- create audit entry for the shared network which
+            -- indicates that it should be treated as the shared
+            -- network update.
+           SELECT id INTO snid FROM dhcp6_shared_network
+                WHERE name = network_name LIMIT 1;
+           PERFORM createAuditEntryDHCP6('dhcp6_shared_network', snid, 'update');
+        ELSEIF scope_id = 5 THEN
+            -- If pool specific option is added or modified, create
+            -- audit entry for the subnet which this pool belongs to.
+            SELECT dhcp6_pool.subnet_id INTO sid FROM dhcp6_pool WHERE id = pool_id;
+            PERFORM createAuditEntryDHCP6('dhcp6_subnet', sid, 'update');
+        ELSEIF scope_id = 6 THEN
+            -- If pd pool specific option is added or modified, create
+            -- audit entry for the subnet which this pd pool belongs to.
+            SELECT dhcp6_pd_pool.subnet_id INTO sid FROM dhcp6_pd_pool
+                WHERE id = pd_pool_id;
+            PERFORM createAuditEntryDHCP6('dhcp6_subnet', sid, 'update');
+        END IF;
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- Trigger function for dhcp6_options_AINS called AFTER INSERT on dhcp6_options
+CREATE OR REPLACE FUNCTION func_dhcp6_options_AINS() RETURNS TRIGGER AS \$dhcp6_options_AINS\$
+BEGIN
+    PERFORM createOptionAuditDHCP6('create', NEW.scope_id, NEW.option_id, NEW.dhcp6_subnet_id,
+                                   NEW.host_id, NEW.shared_network_name, NEW.pool_id,
+                                   NEW.pd_pool_id, NEW.modification_ts);
+    RETURN NULL;
+END;
+\$dhcp6_options_AINS\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_options_AINS
+    AFTER INSERT ON dhcp6_options
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_options_AINS();
+
+-- Trigger function for dhcp6_options_AUPD called AFTER UPDATE on dhcp6_options
+CREATE OR REPLACE FUNCTION func_dhcp6_options_AUPD() RETURNS TRIGGER AS \$dhcp6_options_AUPD\$
+BEGIN
+    PERFORM createOptionAuditDHCP6('update', NEW.scope_id, NEW.option_id, NEW.dhcp6_subnet_id,
+                                   NEW.host_id, NEW.shared_network_name, NEW.pool_id,
+                                   NEW.pd_pool_id, NEW.modification_ts);
+    RETURN NULL;
+END;
+\$dhcp6_options_AUPD\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_options_AUPD
+    AFTER UPDATE ON dhcp6_options
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_options_AUPD();
+
+-- Trigger function for dhcp6_options_ADEL called AFTER DELETE on dhcp6_options
+CREATE OR REPLACE FUNCTION func_dhcp6_options_ADEL() RETURNS TRIGGER AS \$dhcp6_options_ADEL\$
+BEGIN
+    PERFORM createOptionAuditDHCP6('delete', OLD.scope_id, OLD.option_id, OLD.dhcp6_subnet_id,
+                                   OLD.host_id, OLD.shared_network_name, OLD.pool_id,
+                                   OLD.pd_pool_id, NOW());
+    RETURN NULL;
+END;
+\$dhcp6_options_ADEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_options_ADEL
+    AFTER DELETE ON dhcp6_options
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_options_ADEL();
+
+-- Trigger function for dhcp4_server_AINS called AFTER INSERT on dhcp4_server
+CREATE OR REPLACE FUNCTION func_dhcp4_server_AINS() RETURNS TRIGGER AS \$dhcp4_server_AINS\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_server', NEW.id, 'create');
+    RETURN NULL;
+END;
+\$dhcp4_server_AINS\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_server_AINS
+    AFTER INSERT ON dhcp4_server
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_server_AINS();
+
+-- Trigger function for dhcp4_server_AUPD called AFTER UPDATE on dhcp4_server
+CREATE OR REPLACE FUNCTION func_dhcp4_server_AUPD() RETURNS TRIGGER AS \$dhcp4_server_AUPD\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_server', NEW.id, 'update');
+    RETURN NULL;
+END;
+\$dhcp4_server_AUPD\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_server_AUPD
+    AFTER UPDATE ON dhcp4_server
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_server_AUPD();
+
+-- Trigger function for dhcp4_server_ADEL called AFTER DELETE on dhcp4_server
+CREATE OR REPLACE FUNCTION func_dhcp4_server_ADEL() RETURNS TRIGGER AS \$dhcp4_server_ADEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_server', OLD.id, 'delete');
+    RETURN NULL;
+END;
+\$dhcp4_server_ADEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_server_ADEL
+    AFTER DELETE ON dhcp4_server
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_server_ADEL();
+
+-- Trigger function for dhcp6_server_AINS called AFTER INSERT on dhcp6_server
+CREATE OR REPLACE FUNCTION func_dhcp6_server_AINS() RETURNS TRIGGER AS \$dhcp6_server_AINS\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_server', NEW.id, 'create');
+    RETURN NULL;
+END;
+\$dhcp6_server_AINS\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_server_AINS
+    AFTER INSERT ON dhcp6_server
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_server_AINS();
+
+-- Trigger function for dhcp6_server_AUPD called AFTER UPDATE on dhcp6_server
+CREATE OR REPLACE FUNCTION func_dhcp6_server_AUPD() RETURNS TRIGGER AS \$dhcp6_server_AUPD\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_server', NEW.id, 'update');
+    RETURN NULL;
+END;
+\$dhcp6_server_AUPD\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_server_AUPD
+    AFTER UPDATE ON dhcp6_server
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_server_AUPD();
+
+-- Trigger function for dhcp6_server_ADEL called AFTER DELETE on dhcp6_server
+CREATE OR REPLACE FUNCTION func_dhcp6_server_ADEL() RETURNS TRIGGER AS \$dhcp6_server_ADEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_server', OLD.id, 'delete');
+    RETURN NULL;
+END;
+\$dhcp6_server_ADEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_server_ADEL
+    AFTER DELETE ON dhcp6_server
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_server_ADEL();
+
+-- Trigger function for dhcp4_shared_network_BDEL called BEFORE DELETE on dhcp4_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp4_shared_network_BDEL() RETURNS TRIGGER AS \$dhcp4_shared_network_BDEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_shared_network', OLD.id, 'delete');
+    DELETE FROM dhcp4_options WHERE shared_network_name = OLD.name;
+    RETURN OLD;
+END;
+\$dhcp4_shared_network_BDEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_shared_network_BDEL
+    BEFORE DELETE ON dhcp4_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_shared_network_BDEL();
+
+-- Trigger function for dhcp4_subnet_BDEL called BEFORE DELETE on dhcp4_subnet
+CREATE OR REPLACE FUNCTION func_dhcp4_subnet_BDEL() RETURNS TRIGGER AS \$dhcp4_subnet_BDEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_subnet', OLD.subnet_id, 'delete');
+    DELETE FROM dhcp4_pool WHERE subnet_id = OLD.subnet_id;
+    DELETE FROM dhcp4_options WHERE dhcp4_subnet_id = OLD.subnet_id;
+    RETURN OLD;
+END;
+\$dhcp4_subnet_BDEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp4_subnet_BDEL
+    BEFORE DELETE ON dhcp4_subnet
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp4_subnet_BDEL();
+
+-- Trigger function for dhcp6_shared_network_BDEL called BEFORE DELETE on dhcp6_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp6_shared_network_BDEL() RETURNS TRIGGER AS \$dhcp6_shared_network_BDEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_shared_network', OLD.id, 'delete');
+    DELETE FROM dhcp6_options WHERE shared_network_name = OLD.name;
+    RETURN OLD;
+END;
+\$dhcp6_shared_network_BDEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_shared_network_BDEL
+    BEFORE DELETE ON dhcp6_shared_network
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_shared_network_BDEL();
+
+-- Trigger function for dhcp6_subnet_BDEL called BEFORE DELETE on dhcp6_subnet
+CREATE OR REPLACE FUNCTION func_dhcp6_subnet_BDEL() RETURNS TRIGGER AS \$dhcp6_subnet_BDEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_subnet', OLD.subnet_id, 'delete');
+    DELETE FROM dhcp6_pool WHERE subnet_id = OLD.subnet_id;
+    DELETE FROM dhcp6_pd_pool WHERE subnet_id = OLD.subnet_id;
+    DELETE FROM dhcp6_options WHERE dhcp6_subnet_id = OLD.subnet_id;
+    RETURN OLD;
+END;
+\$dhcp6_subnet_BDEL\$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER dhcp6_subnet_BDEL
+    BEFORE DELETE ON dhcp6_subnet
+        FOR EACH ROW EXECUTE PROCEDURE func_dhcp6_subnet_BDEL();
+
+-- Trigger function for dhcp6_pd_pool_BDEL called BEFORE DELETE on dhcp6_pd_pool
+CREATE OR REPLACE FUNCTION func_dhcp6_pd_pool_BDEL() RETURNS TRIGGER AS \$dhcp6_pd_pool_BDEL\$
+BEGIN
+    DELETE FROM dhcp6_options WHERE scope_id = 6 AND pd_pool_id = OLD.id;
+    RETURN OLD;
+END;
+\$dhcp6_pd_pool_BDEL\$
+LANGUAGE plpgsql;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '7', minor = '0';
+
+-- This line concludes the schema upgrade to version 7.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_007_to_008.sh.in b/src/share/database/scripts/pgsql/upgrade_007_to_008.sh.in
new file mode 100644
index 0000000..1205336
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_007_to_008.sh.in
@@ -0,0 +1,518 @@
+#!/bin/sh
+
+# Copyright (C) 2021-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "7.0" ]; then
+    printf 'This script upgrades 7.0 to 8.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 8.0.
+
+-- Adds a few missing elements for CB and functions for kea-admin's lease-dump
+-- and lease-upload commands.
+
+-- -----------------------------------------------------------------------
+-- Extend the table holding DHCPv4 option definitions with a nullable
+-- column matching option defintions with client classes.
+-- -----------------------------------------------------------------------
+ALTER TABLE dhcp4_option_def
+    ADD COLUMN class_id BIGINT NULL DEFAULT NULL;
+
+ALTER TABLE dhcp4_option_def
+  ADD CONSTRAINT fk_dhcp4_option_def_client_class_id
+    FOREIGN KEY (class_id)
+    REFERENCES dhcp4_client_class (id)
+    ON DELETE CASCADE
+    ON UPDATE CASCADE;
+
+-- -----------------------------------------------------------------------
+-- Extend the table holding DHCPv6 option definitions with a nullable
+-- column matching option defintions with client classes.
+-- -----------------------------------------------------------------------
+ALTER TABLE dhcp6_option_def
+    ADD COLUMN class_id BIGINT NULL DEFAULT NULL;
+
+ALTER TABLE dhcp6_option_def
+  ADD CONSTRAINT fk_dhcp6_option_def_client_class_id
+    FOREIGN KEY (class_id)
+    REFERENCES dhcp6_client_class (id)
+    ON DELETE CASCADE
+    ON UPDATE CASCADE;
+
+-- -----------------------------------------------------------------------
+-- Add missing preferred_lifetime columns to dhcp6_client_class table.
+-- -----------------------------------------------------------------------
+ALTER TABLE dhcp6_client_class
+    ADD COLUMN preferred_lifetime BIGINT DEFAULT NULL,
+    ADD COLUMN min_preferred_lifetime BIGINT DEFAULT NULL,
+    ADD COLUMN max_preferred_lifetime BIGINT DEFAULT NULL;
+
+-- -----------------------------------------------------------------------
+-- Add option scopes
+-- -----------------------------------------------------------------------
+-- Add scope for shared network specific options.
+INSERT INTO dhcp_option_scope (scope_id, scope_name)
+    VALUES(4, 'shared-network');
+
+-- Add scope for pool specific options.
+INSERT INTO dhcp_option_scope (scope_id, scope_name)
+    VALUES(5, 'pool');
+
+-- Add scope for PD pool specific options.
+INSERT INTO dhcp_option_scope (scope_id, scope_name)
+    VALUES(6, 'pd-pool');
+
+
+-- Drop the existing function, createOptionAuditDHCP6 so we can replace it
+-- with one that has slightly different arguments.
+DROP FUNCTION IF EXISTS createOptionAuditDHCP6(modification_type VARCHAR(32),
+                                               scope_id SMALLINT, option_id INT, subnet_id BIGINT,
+                                               host_id INT, network_name VARCHAR(128),
+                                               pool_id BIGINT, pd_pool_id BIGINT,
+                                               modification_ts TIMESTAMP WITH TIME ZONE);
+
+-- -----------------------------------------------------
+--
+-- New version of the createOptionAuditDHCP6 stored
+-- procedure which updates modification timestamp of
+-- a parent object when an option is modified.
+--
+-- The following parameters are passed to the procedure:
+-- - modification_type: "create", "update" or "delete"
+-- - scope_id: identifier of the option scope, e.g.
+--   global, subnet specific etc. See dhcp_option_scope
+--   for specific values.
+-- - option_id: identifier of the option.
+-- - subnet_id: identifier of the subnet if the option
+--   belongs to the subnet.
+-- - host_id: identifier of the host if the option
+-- - belongs to the host.
+-- - network_name: shared network name if the option
+--   belongs to the shared network.
+-- - pool_id: identifier of the pool if the option
+--   belongs to the pool.
+-- - pd_pool_id: identifier of the pool if the option
+--   belongs to the pd pool.
+-- - modification_ts: modification timestamp of the
+--   option.
+--   Some arguments are prefixed with "p_" to avoid ambiguity
+--   with column names in SQL statements. PostgreSQL does not
+--   allow table aliases to be used with column names in update
+--   set expressions.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createOptionAuditDHCP6(modification_type VARCHAR(32),
+                                                  scope_id SMALLINT,
+                                                  option_id INT,
+                                                  p_subnet_id BIGINT,
+                                                  host_id INT,
+                                                  network_name VARCHAR(128),
+                                                  pool_id BIGINT,
+                                                  pd_pool_id BIGINT,
+                                                  p_modification_ts TIMESTAMP WITH TIME ZONE)
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    -- These variables will hold shared network id and subnet id that
+    -- we will select.
+    snid VARCHAR(128);
+    sid BIGINT;
+    cascade_transaction BOOLEAN := false;
+
+BEGIN
+    -- Cascade transaction flag is set to true to prevent creation of
+    -- the audit entries for the options when the options are
+    -- created as part of the parent object creation or update.
+    -- For example: when the option is added as part of the subnet
+    -- addition, the cascade transaction flag is equal to true. If
+    -- the option is added into the existing subnet the cascade
+    -- transaction is equal to false. Note that depending on the option
+    -- scope the audit entry will contain the object_type value
+    -- of the parent object to cause the server to replace the
+    -- entire subnet. The only case when the object_type will be
+    -- set to 'dhcp6_options' is when a global option is added.
+    -- Global options do not have the owner.
+    cascade_transaction := get_session_boolean('kea.cascade_transaction');
+    IF cascade_transaction = false THEN
+        -- todo: host manager hasn't been updated to use audit
+        -- mechanisms so ignore host specific options for now.
+        IF scope_id = 0 THEN
+            -- If a global option is added or modified, create audit
+            -- entry for the 'dhcp6_options' table.
+            PERFORM createAuditEntryDHCP6('dhcp6_options', option_id, modification_type);
+        ELSEIF scope_id = 1 THEN
+            -- If subnet specific option is added or modified, update
+            -- the modification timestamp of this subnet to allow the
+            -- servers to refresh the subnet information. This will
+            -- also result in creating an audit entry for this subnet.
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = p_subnet_id;
+        ELSEIF scope_id = 4 THEN
+            -- If shared network specific option is added or modified,
+            -- update the modification timestamp of this shared network
+            -- to allow the servers to refresh the shared network
+            -- information. This will also result in creating an
+            -- audit entry for this shared network.
+           SELECT id INTO snid FROM dhcp6_shared_network WHERE name = network_name LIMIT 1;
+           UPDATE dhcp6_shared_network SET modification_ts = p_modification_ts
+                WHERE id = snid;
+        ELSEIF scope_id = 5 THEN
+            -- If pool specific option is added or modified, update
+            -- the modification timestamp of the owning subnet.
+            SELECT dhcp6_pool.subnet_id INTO sid FROM dhcp6_pool WHERE id = pool_id;
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        ELSEIF scope_id = 6 THEN
+            -- If pd pool specific option is added or modified, create
+            -- audit entry for the subnet which this pool belongs to.
+            SELECT dhcp6_pd_pool.subnet_id INTO sid FROM dhcp6_pd_pool WHERE id = pool_id;
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        END IF;
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- Fix mangled constraints on dhcp4_subnet_server table.
+ALTER TABLE dhcp4_subnet_server
+    DROP CONSTRAINT fk_dhcp6_subnet_server_server_id,
+    ADD CONSTRAINT fk_dhcp4_subnet_server_server_id
+        FOREIGN KEY (server_id) REFERENCES dhcp4_server (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+    DROP CONSTRAINT fk_dhcp6_subnet_server_subnet_id,
+    ADD CONSTRAINT fk_dhcp4_subnet_server_subnet_id
+        FOREIGN KEY (subnet_id) REFERENCES dhcp4_subnet (subnet_id) ON DELETE CASCADE ON UPDATE NO ACTION;
+
+-- Add missing foreign key indexes. PostgreSQL does not automatically create indexes for
+-- foreign key constraints. These have been added using the basic guideline:
+--
+-- If the constraint does not reference a static table (e.g. parameter_data_type),
+-- and the referencing column is not the primary key or the first
+-- column in the primary key, and does not already have an index, then an index
+-- should be added to the table for the referencing column.
+--
+-- dhcp6_global_parameter_server
+CREATE INDEX  fk_dhcp6_global_parameter_server_server_id ON dhcp6_global_parameter_server (server_id);
+
+-- dhcp6_options
+-- Missing foreign key constraint and indexes
+ALTER TABLE dhcp6_options ADD CONSTRAINT fk_dhcp6_options_subnet
+    FOREIGN KEY (dhcp6_subnet_id)
+        REFERENCES dhcp6_subnet(subnet_id)
+        ON DELETE CASCADE ON UPDATE CASCADE;
+
+CREATE INDEX fk_dhcp6_options_subnet ON dhcp6_options (dhcp6_subnet_id);
+CREATE INDEX fk_dhcp6_options_pd_pool ON dhcp6_options (pd_pool_id);
+CREATE INDEX fk_dhcp6_options_pool ON dhcp6_options (pool_id);
+CREATE INDEX fk_dhcp6_options_shared_network ON dhcp6_options (shared_network_name);
+
+-- dhcp6_option_def_server
+-- Missing foreign key constraints and index
+ALTER TABLE dhcp6_option_def_server
+    ADD CONSTRAINT fk_dhcp6_option_def_server_option_def_id FOREIGN KEY (option_def_id)
+        REFERENCES dhcp6_option_def (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+    ADD CONSTRAINT fk_dhcp6_option_def_server_server_id FOREIGN KEY (server_id)
+        REFERENCES dhcp6_server (id) ON DELETE NO ACTION ON UPDATE NO ACTION;
+
+CREATE INDEX fk_dhcp6_option_def_server_server_id ON dhcp6_option_def_server (server_id);
+
+-- dhcp6_option_def
+CREATE INDEX fk_dhcp6_option_def_client_class_id ON dhcp6_option_def (class_id);
+
+-- dhcp4_global_parameter_server
+CREATE INDEX  fk_dhcp4_global_parameter_server_server_id ON dhcp4_global_parameter_server (server_id);
+
+-- dhcp4_options
+-- Missing foreign key constraint and indexes
+ALTER TABLE dhcp4_options ADD CONSTRAINT fk_dhcp4_options_subnet
+    FOREIGN KEY (dhcp4_subnet_id)
+        REFERENCES dhcp4_subnet(subnet_id)
+        ON DELETE CASCADE ON UPDATE CASCADE;
+
+CREATE INDEX fk_dhcp4_options_subnet ON dhcp4_options (dhcp4_subnet_id);
+CREATE INDEX fk_dhcp4_options_pool ON dhcp4_options (pool_id);
+CREATE INDEX fk_dhcp4_options_shared_network ON dhcp4_options (shared_network_name);
+
+-- dhcp4_option_def_server
+-- Missing foreign key constraints and index
+ALTER TABLE dhcp4_option_def_server
+    ADD CONSTRAINT fk_dhcp4_option_def_server_option_def_id FOREIGN KEY (option_def_id)
+        REFERENCES dhcp4_option_def (id) ON DELETE CASCADE ON UPDATE NO ACTION,
+    ADD CONSTRAINT fk_dhcp4_option_def_server_server_id FOREIGN KEY (server_id)
+        REFERENCES dhcp4_server (id) ON DELETE NO ACTION ON UPDATE NO ACTION;
+
+CREATE INDEX fk_dhcp4_option_def_server_server_id ON dhcp4_option_def_server (server_id);
+
+-- dhcp4_option_def
+CREATE INDEX fk_dhcp4_option_def_client_class_id ON dhcp4_option_def (class_id);
+
+-- Create a function that separates groups of two hexadecimals
+-- with colons.
+CREATE OR REPLACE FUNCTION colonSeparatedHex(hex TEXT)
+RETURNS TEXT
+AS \$\$
+DECLARE
+    i INT := 3;
+    length INT := LENGTH(hex);
+    output TEXT;
+BEGIN
+    -- Add a leading zero if the first octet has a single hexadecimal character.
+    IF MOD(length, 2) = 1 THEN
+        hex := CONCAT('0', hex);
+        length := length + 1;
+    END IF;
+
+    -- Start with the first octet.
+    output := SUBSTR(hex, 1, 2);
+
+    -- Add one octet at a time and a leading colon with each.
+    WHILE i < length LOOP
+        output := CONCAT(output, ':', SUBSTR(hex, i, 2));
+        i := i + 2;
+    END LOOP;
+
+    -- Memfile uses lowercase hexadecimals.
+    output := LOWER(output);
+
+    RETURN output;
+END
+\$\$ LANGUAGE plpgsql;
+
+-- Modify the function to output a memfile-ready CSV file.
+-- Some columns that are SMALLINT in the lease4 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+DROP FUNCTION IF EXISTS lease4DumpData();
+CREATE OR REPLACE FUNCTION lease4DumpData()
+RETURNS TABLE (
+    address INET,
+    hwaddr VARCHAR,
+    client_id VARCHAR,
+    valid_lifetime BIGINT,
+    expire BIGINT,
+    subnet_id BIGINT,
+    fqdn_fwd INT,
+    fqdn_rev INT,
+    hostname VARCHAR,
+    state INT8,
+    user_context VARCHAR
+) AS \$\$
+    SELECT
+        ('0.0.0.0'::inet + address),
+        colonSeparatedHex(encode(hwaddr, 'hex')),
+        colonSeparatedHex(encode(client_id, 'hex')),
+        valid_lifetime,
+        extract(epoch from expire)::bigint,
+        subnet_id,
+        fqdn_fwd::int,
+        fqdn_rev::int,
+        replace(hostname, ',', '&#x2c'),
+        state,
+        replace(user_context, ',', '&#x2c')
+    FROM lease4
+    ORDER BY address;
+\$\$ LANGUAGE SQL;
+
+-- hwtype and hwaddr_source need to be last to match memfile format.
+DROP FUNCTION IF EXISTS lease6DumpHeader();
+CREATE OR REPLACE FUNCTION lease6DumpHeader()
+RETURNS TEXT AS \$\$
+    SELECT CAST('address,duid,valid_lifetime,expire,subnet_id,pref_lifetime,lease_type,iaid,prefix_len,fqdn_fwd,fqdn_rev,hostname,hwaddr,state,user_context,hwtype,hwaddr_source' AS TEXT) AS result;
+\$\$ LANGUAGE SQL;
+
+-- Modify the function to output a memfile-ready CSV file.
+-- Some columns that are SMALLINT in the lease6 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+DROP FUNCTION IF EXISTS lease6DumpData();
+CREATE OR REPLACE FUNCTION lease6DumpData()
+RETURNS TABLE (
+    address VARCHAR,
+    duid VARCHAR,
+    valid_lifetime BIGINT,
+    expire BIGINT,
+    subnet_id BIGINT,
+    pref_lifetime BIGINT,
+    lease_type SMALLINT,
+    iaid INT,
+    prefix_len SMALLINT,
+    fqdn_fwd INT,
+    fqdn_rev INT,
+    hostname VARCHAR,
+    hwaddr VARCHAR,
+    state INT8,
+    user_context VARCHAR,
+    hwtype SMALLINT,
+    hwaddr_source SMALLINT
+) AS \$\$
+    SELECT
+        address,
+        colonSeparatedHex(encode(duid, 'hex')),
+        valid_lifetime,
+        extract(epoch from expire)::bigint,
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd::int,
+        fqdn_rev::int,
+        replace(hostname, ',', '&#x2c'),
+        colonSeparatedHex(encode(hwaddr, 'hex')),
+        state,
+        replace(user_context, ',', '&#x2c'),
+        hwtype,
+        hwaddr_source
+    FROM lease6
+    ORDER BY address;
+\$\$ LANGUAGE SQL;
+
+-- Create a procedure that inserts a v4 lease from memfile data.
+-- Some columns that are SMALLINT in the lease4 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+CREATE OR REPLACE FUNCTION lease4Upload(
+    IN address VARCHAR,
+    IN hwaddr VARCHAR,
+    IN client_id VARCHAR,
+    IN valid_lifetime BIGINT,
+    IN expire BIGINT,
+    IN subnet_id BIGINT,
+    IN fqdn_fwd INT,
+    IN fqdn_rev INT,
+    IN hostname VARCHAR,
+    IN state INT8,
+    IN user_context VARCHAR
+) RETURNS VOID AS \$\$
+BEGIN
+    INSERT INTO lease4 (
+        address,
+        hwaddr,
+        client_id,
+        valid_lifetime,
+        expire,
+        subnet_id,
+        fqdn_fwd,
+        fqdn_rev,
+        hostname,
+        state,
+        user_context
+    ) VALUES (
+        address::inet - '0.0.0.0'::inet,
+        decode(replace(hwaddr, ':', ''), 'hex'),
+        decode(replace(client_id, ':', ''), 'hex'),
+        valid_lifetime,
+        to_timestamp(expire),
+        subnet_id,
+        fqdn_fwd::int::boolean,
+        fqdn_rev::int::boolean,
+        replace(hostname, '&#x2c', ','),
+        state,
+        replace(user_context, '&#x2c', ',')
+    );
+END
+\$\$ LANGUAGE plpgsql;
+
+-- Create a procedure that inserts a v6 lease from memfile data.
+-- Some columns that are SMALLINT in the lease6 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+CREATE OR REPLACE FUNCTION lease6Upload(
+    IN address VARCHAR,
+    IN duid VARCHAR,
+    IN valid_lifetime BIGINT,
+    IN expire BIGINT,
+    IN subnet_id BIGINT,
+    IN pref_lifetime BIGINT,
+    IN lease_type INT,
+    IN iaid INT,
+    IN prefix_len INT,
+    IN fqdn_fwd INT,
+    IN fqdn_rev INT,
+    IN hostname VARCHAR,
+    IN hwaddr VARCHAR,
+    IN state INT8,
+    IN user_context VARCHAR,
+    IN hwtype INT,
+    IN hwaddr_source INT
+) RETURNS VOID AS \$\$
+BEGIN
+    INSERT INTO lease6 (
+        address,
+        duid,
+        valid_lifetime,
+        expire,
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd,
+        fqdn_rev,
+        hostname,
+        hwaddr,
+        state,
+        user_context,
+        hwtype,
+        hwaddr_source
+    ) VALUES (
+        address,
+        decode(replace(duid, ':', ''), 'hex'),
+        valid_lifetime,
+        to_timestamp(expire),
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd::int::boolean,
+        fqdn_rev::int::boolean,
+        replace(hostname, '&#x2c', ','),
+        decode(replace(hwaddr, ':', ''), 'hex'),
+        state,
+        replace(user_context, '&#x2c', ','),
+        hwtype,
+        hwaddr_source
+    );
+END
+\$\$ LANGUAGE plpgsql;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '8', minor = '0';
+
+-- This line concludes the schema upgrade to version 8.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_008_to_009.sh.in b/src/share/database/scripts/pgsql/upgrade_008_to_009.sh.in
new file mode 100644
index 0000000..1adb722
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_008_to_009.sh.in
@@ -0,0 +1,294 @@
+#!/bin/sh
+
+# Copyright (C) 2022-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "8.0" ]; then
+    printf 'This script upgrades 8.0 to 9.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 9.0.
+
+-- Add missing cascade to constraint on dhcp4/6_subnet_server tables.
+ALTER TABLE dhcp4_subnet_server
+    DROP CONSTRAINT fk_dhcp4_subnet_server_server_id,
+    ADD CONSTRAINT fk_dhcp4_subnet_server_server_id
+        FOREIGN KEY (server_id) REFERENCES dhcp4_server (id) ON DELETE CASCADE ON UPDATE CASCADE,
+    DROP CONSTRAINT fk_dhcp4_subnet_server_subnet_id,
+    ADD CONSTRAINT fk_dhcp4_subnet_server_subnet_id
+        FOREIGN KEY (subnet_id) REFERENCES dhcp4_subnet (subnet_id) ON DELETE CASCADE ON UPDATE CASCADE;
+
+ALTER TABLE dhcp6_subnet_server
+    DROP CONSTRAINT fk_dhcp6_subnet_server_server_id,
+    ADD CONSTRAINT fk_dhcp6_subnet_server_server_id
+        FOREIGN KEY (server_id) REFERENCES dhcp6_server (id) ON DELETE CASCADE ON UPDATE CASCADE,
+    DROP CONSTRAINT fk_dhcp6_subnet_server_subnet_id,
+    ADD CONSTRAINT fk_dhcp6_subnet_server_subnet_id
+        FOREIGN KEY (subnet_id) REFERENCES dhcp6_subnet (subnet_id) ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- Fix constraint typo on dhcp4_option_def_server
+ALTER TABLE dhcp4_option_def_server
+    DROP CONSTRAINT dhcp4_option_def_server_option_def_id_fkey,
+    ADD CONSTRAINT dhcp4_option_def_server_option_def_id_fkey
+        FOREIGN KEY (option_def_id) REFERENCES dhcp4_option_def(id) ON DELETE CASCADE;
+
+-- DROP shared-network ADEL triggers that should not exist.
+DROP TRIGGER IF EXISTS dhcp4_shared_network_ADEL on dhcp4_shared_network CASCADE;
+DROP TRIGGER IF EXISTS dhcp6_shared_network_ADEL on dhcp6_shared_network CASCADE;
+
+-- Replace createOptionAuditDHCP4() with a version that has local variable
+-- snid correctly declared as a BIGINT.
+--
+-- -----------------------------------------------------
+--
+-- Stored procedure which updates modification timestamp of
+-- a parent object when an option is modified.
+--
+-- The following parameters are passed to the procedure:
+-- - modification_type: "create", "update" or "delete"
+-- - scope_id: identifier of the option scope, e.g.
+--   global, subnet specific etc. See dhcp_option_scope
+--   for specific values.
+-- - option_id: identifier of the option.
+-- - p_subnet_id: identifier of the subnet if the option
+--   belongs to the subnet.
+-- - host_id: identifier of the host if the option
+-- - belongs to the host.
+-- - network_name: shared network name if the option
+--   belongs to the shared network.
+-- - pool_id: identifier of the pool if the option
+--   belongs to the pool.
+-- - p_modification_ts: modification timestamp of the
+--   option.
+--   Some arguments are prefixed with "p_" to avoid ambiguity
+--   with column names in SQL statements. PostgreSQL does not
+--   allow table aliases to be used with column names in update
+--   set expressions.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createOptionAuditDHCP4(modification_type VARCHAR,
+                                                  scope_id SMALLINT,
+                                                  option_id INT,
+                                                  p_subnet_id BIGINT,
+                                                  host_id INT,
+                                                  network_name VARCHAR,
+                                                  pool_id BIGINT,
+                                                  p_modification_ts TIMESTAMP WITH TIME ZONE)
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    -- These variables will hold shared network id and subnet id that
+    -- we will select.
+    snid BIGINT;
+    sid BIGINT;
+    cascade_transaction BOOLEAN;
+BEGIN
+    -- Cascade transaction flag is set to true to prevent creation of
+    -- the audit entries for the options when the options are
+    -- created as part of the parent object creation or update.
+    -- For example: when the option is added as part of the subnet
+    -- addition, the cascade transaction flag is equal to true. If
+    -- the option is added into the existing subnet the cascade
+    -- transaction is equal to false. Note that depending on the option
+    -- scope the audit entry will contain the object_type value
+    -- of the parent object to cause the server to replace the
+    -- entire subnet. The only case when the object_type will be
+    -- set to 'dhcp4_options' is when a global option is added.
+    -- Global options do not have the owner.
+
+    cascade_transaction := get_session_boolean('kea.cascade_transaction');
+    IF cascade_transaction = false THEN
+        -- todo: host manager hasn't been updated to use audit
+        -- mechanisms so ignore host specific options for now.
+        IF scope_id = 0 THEN
+            -- If a global option is added or modified, create audit
+            -- entry for the 'dhcp4_options' table.
+            PERFORM createAuditEntryDHCP4('dhcp4_options', option_id, modification_type);
+        ELSEIF scope_id = 1 THEN
+            -- If subnet specific option is added or modified, update
+            -- the modification timestamp of this subnet to allow the
+            -- servers to refresh the subnet information. This will
+            -- also result in creating an audit entry for this subnet.
+            UPDATE dhcp4_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = p_subnet_id;
+        ELSEIF scope_id = 4 THEN
+            -- If shared network specific option is added or modified,
+            -- update the modification timestamp of this shared network
+            -- to allow the servers to refresh the shared network
+            -- information. This will also result in creating an
+            -- audit entry for this shared network.
+           SELECT id INTO snid FROM dhcp4_shared_network WHERE name = network_name LIMIT 1;
+           UPDATE dhcp4_shared_network SET modification_ts = p_modification_ts
+                WHERE id = snid;
+        ELSEIF scope_id = 5 THEN
+            -- If pool specific option is added or modified, update
+            -- the modification timestamp of the owning subnet.
+            SELECT dhcp4_pool.subnet_id INTO sid FROM dhcp4_pool WHERE id = pool_id;
+            UPDATE dhcp4_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        END IF;
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- Replace createOptionAuditDHCP6() with a version that has local variable
+-- snid correctly declared as a BIGINT.
+--
+-- -----------------------------------------------------
+--
+-- Stored procedure which updates modification timestamp of
+-- a parent object when an option is modified.
+--
+-- The following parameters are passed to the procedure:
+-- - modification_type: "create", "update" or "delete"
+-- - scope_id: identifier of the option scope, e.g.
+--   global, subnet specific etc. See dhcp_option_scope
+--   for specific values.
+-- - option_id: identifier of the option.
+-- - p_subnet_id: identifier of the subnet if the option
+--   belongs to the subnet.
+-- - host_id: identifier of the host if the option
+-- - belongs to the host.
+-- - network_name: shared network name if the option
+--   belongs to the shared network.
+-- - pool_id: identifier of the pool if the option
+--   belongs to the pool.
+-- - pd_pool_id: identifier of the pool if the option
+--   belongs to the pd pool.
+-- - p_modification_ts: modification timestamp of the
+--   option.
+--   Some arguments are prefixed with "p_" to avoid ambiguity
+--   with column names in SQL statements. PostgreSQL does not
+--   allow table aliases to be used with column names in update
+--   set expressions.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createOptionAuditDHCP6(modification_type VARCHAR,
+                                                  scope_id SMALLINT,
+                                                  option_id INT,
+                                                  p_subnet_id BIGINT,
+                                                  host_id INT,
+                                                  network_name VARCHAR,
+                                                  pool_id BIGINT,
+                                                  pd_pool_id BIGINT,
+                                                  p_modification_ts TIMESTAMP WITH TIME ZONE)
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    -- These variables will hold shared network id and subnet id that
+    -- we will select.
+    snid BIGINT;
+    sid BIGINT;
+    cascade_transaction BOOLEAN;
+BEGIN
+    -- Cascade transaction flag is set to true to prevent creation of
+    -- the audit entries for the options when the options are
+    -- created as part of the parent object creation or update.
+    -- For example: when the option is added as part of the subnet
+    -- addition, the cascade transaction flag is equal to true. If
+    -- the option is added into the existing subnet the cascade
+    -- transaction is equal to false. Note that depending on the option
+    -- scope the audit entry will contain the object_type value
+    -- of the parent object to cause the server to replace the
+    -- entire subnet. The only case when the object_type will be
+    -- set to 'dhcp6_options' is when a global option is added.
+    -- Global options do not have the owner.
+
+    cascade_transaction := get_session_boolean('kea.cascade_transaction');
+    IF cascade_transaction = false THEN
+        -- todo: host manager hasn't been updated to use audit
+        -- mechanisms so ignore host specific options for now.
+        IF scope_id = 0 THEN
+            -- If a global option is added or modified, create audit
+            -- entry for the 'dhcp6_options' table.
+            PERFORM createAuditEntryDHCP6('dhcp6_options', option_id, modification_type);
+        ELSEIF scope_id = 1 THEN
+            -- If subnet specific option is added or modified, update
+            -- the modification timestamp of this subnet to allow the
+            -- servers to refresh the subnet information. This will
+            -- also result in creating an audit entry for this subnet.
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = p_subnet_id;
+        ELSEIF scope_id = 4 THEN
+            -- If shared network specific option is added or modified,
+            -- update the modification timestamp of this shared network
+            -- to allow the servers to refresh the shared network
+            -- information. This will also result in creating an
+            -- audit entry for this shared network.
+           SELECT id INTO snid FROM dhcp6_shared_network WHERE name = network_name LIMIT 1;
+           UPDATE dhcp6_shared_network SET modification_ts = p_modification_ts
+                WHERE id = snid;
+        ELSEIF scope_id = 5 THEN
+            -- If pool specific option is added or modified, update
+            -- the modification timestamp of the owning subnet.
+            SELECT dhcp6_pool.subnet_id INTO sid FROM dhcp6_pool WHERE id = pool_id;
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        ELSEIF scope_id = 6 THEN
+            -- If pd pool specific option is added or modified, create
+            -- audit entry for the subnet which this pool belongs to.
+            SELECT dhcp6_pd_pool.subnet_id INTO sid FROM dhcp6_pd_pool WHERE id = pool_id;
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        END IF;
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- Returns the epoch GMT time in second from a timestamp with time zone
+--
+-- param input_ts timestamp value to convert
+-- return a BIGINT containing the number of seconds since the epoch in GMT.
+CREATE OR REPLACE FUNCTION gmt_epoch(input_ts TIMESTAMP WITH TIME ZONE)
+RETURNS BIGINT
+AS \$\$
+DECLARE
+    gmt_epoch BIGINT;
+BEGIN
+    SELECT (extract(epoch from input_ts) + extract(timezone from input_ts))::BIGINT INTO gmt_epoch;
+    RETURN gmt_epoch;
+    EXCEPTION
+    WHEN OTHERS THEN
+        RAISE EXCEPTION 'gmt_epoch(%) : failed, sqlstate: %', input_ts, sqlstate;
+END;\$\$
+LANGUAGE plpgsql;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '9', minor = '0';
+
+-- This line concludes the schema upgrade to version 9.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_009_to_010.sh.in b/src/share/database/scripts/pgsql/upgrade_009_to_010.sh.in
new file mode 100644
index 0000000..3966f89
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_009_to_010.sh.in
@@ -0,0 +1,338 @@
+#!/bin/sh
+
+# Copyright (C) 2022-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "9.0" ]; then
+    printf 'This script upgrades 9.0 to 10.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 10.0.
+
+-- It adds corrections for client classes for CB
+
+-- Replace setClientClass4Order():
+-- 1. l_depend_on_known_indirectly needs to be BOOL
+-- 2. follow_class_index needs to be BIGINT
+
+-- -----------------------------------------------------------------------
+-- Stored procedure positioning an inserted or updated client class
+-- within the class hierarchy, depending on the value of the
+-- new_follow_class_name parameter.
+--
+-- Parameters:
+-- - id id of the positioned class,
+-- - new_follow_class_name name of the class after which this class should be
+--   positioned within the class hierarchy.
+-- - old_follow_class_name previous name of the class after which this
+--   class was positioned within the class hierarchy.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION setClientClass4Order(id BIGINT,
+                                                new_follow_class_name VARCHAR(128),
+                                                old_follow_class_name VARCHAR(128))
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    -- Used to fetch class's current value for depend_on_known_indirectly
+    l_depend_on_known_indirectly BOOL := false;
+
+    -- Optionally set if the follow_class_name column value is specified.
+    follow_class_index BIGINT;
+BEGIN
+    -- Fetch the class's current value of depend_on_known_indirectly.
+    SELECT depend_on_known_indirectly INTO l_depend_on_known_indirectly
+        FROM dhcp4_client_class_order WHERE id = class_id;
+
+    -- Save it to the current session for use elsewhere during this transaction.
+    -- Note this does not work prior to Postgres 9.2 unless the variables are
+    -- defined in postgresql.conf. I think for now we put up with CB not supported
+    -- prior to 9.2 or we tell people how to edit the conf file.
+    PERFORM set_session_value('kea.depend_on_known_indirectly', l_depend_on_known_indirectly);
+
+    -- Bail if the class is updated without re-positioning.
+    IF(
+       l_depend_on_known_indirectly IS NOT NULL AND
+       ((new_follow_class_name IS NULL AND old_follow_class_name IS NULL) OR
+        (new_follow_class_name = old_follow_class_name))
+    ) THEN
+        -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+        -- whenever the dhcp4_client_class record is updated. Such update may include
+        -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+        -- This value will be later adjusted when dependencies are inserted.
+        -- TKM should we update the session value also or is it moot?
+        UPDATE dhcp4_client_class_order SET depend_on_known_indirectly = false
+            WHERE class_id = id;
+        RETURN;
+    END IF;
+
+    IF new_follow_class_name IS NOT NULL THEN
+        -- Get the position of the class after which the new class should be added.
+        SELECT o.order_index INTO follow_class_index
+            FROM dhcp4_client_class AS c
+            INNER JOIN dhcp4_client_class_order AS o
+                ON c.id = o.class_id
+            WHERE c.name = new_follow_class_name;
+
+        IF follow_class_index IS NULL THEN
+            -- The class with a name specified with new_follow_class_name does
+            -- not exist.
+            RAISE EXCEPTION 'Class %s does not exist.', new_follow_class_name
+                USING ERRCODE = 'sql_routine_exception';
+        END IF;
+
+        -- We need to place the new class at the position of follow_class_index + 1.
+        -- There may be a class at this position already.
+        IF EXISTS(SELECT * FROM dhcp4_client_class_order WHERE order_index = follow_class_index + 1) THEN
+            -- There is a class at this position already. Let's move all classes
+            -- starting from this position by one to create a spot for the new
+            -- class.
+            UPDATE dhcp4_client_class_order
+                SET order_index = order_index + 1
+            WHERE order_index >= follow_class_index + 1;
+            -- TKM postgresql doesn't like order by here, does it matter?
+            -- ORDER BY order_index DESC;
+        END IF;
+
+    ELSE
+        -- A caller did not specify the new_follow_class_name value. Let's append the
+        -- new class at the end of the hierarchy.
+        SELECT MAX(order_index) INTO follow_class_index FROM dhcp4_client_class_order;
+        IF follow_class_index IS NULL THEN
+            -- Apparently, there are no classes. Let's start from 0.
+            follow_class_index = 0;
+        END IF;
+    END IF;
+
+    -- Check if moving the class doesn't break dependent classes.
+    IF EXISTS(
+        SELECT 1 FROM dhcp4_client_class_dependency AS d
+            INNER JOIN dhcp4_client_class_order AS o
+                ON d.class_id = o.class_id
+            WHERE d.dependency_id = id AND o.order_index < follow_class_index + 1
+        LIMIT 1
+    ) THEN
+        RAISE EXCEPTION 'Unable to move class with id %s because it would break its dependencies', id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+    -- whenever the dhcp4_client_class record is updated. Such update may include
+    -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+    -- This value will be later adjusted when dependencies are inserted.
+    -- TKM - note that ON CONFLICT requires PostgreSQL 9.5 or later.
+    UPDATE dhcp4_client_class_order
+        SET order_index = follow_class_index + 1,
+            depend_on_known_indirectly = l_depend_on_known_indirectly
+        WHERE class_id = id;
+    IF FOUND THEN
+        RETURN;
+    END IF;
+
+    INSERT INTO  dhcp4_client_class_order(class_id, order_index, depend_on_known_indirectly)
+        VALUES (id, follow_class_index + 1, false);
+    RETURN;
+END;\$\$;
+
+-- Replace setClientClass6Order():
+-- 1. l_depend_on_known_indirectly needs to be BOOL
+-- 2. follow_class_index needs to be BIGINT
+
+-- -----------------------------------------------------------------------
+-- Stored procedure positioning an inserted or updated client class
+-- within the class hierarchy, depending on the value of the
+-- new_follow_class_name parameter.
+--
+-- Parameters:
+-- - id id of the positioned class,
+-- - new_follow_class_name name of the class after which this class should be
+--   positioned within the class hierarchy.
+-- - old_follow_class_name previous name of the class after which this
+--   class was positioned within the class hierarchy.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION setClientClass6Order(id BIGINT,
+                                                new_follow_class_name VARCHAR(128),
+                                                old_follow_class_name VARCHAR(128))
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    -- Used to fetch class's current value for depend_on_known_indirectly
+    l_depend_on_known_indirectly BOOL := false;
+
+    -- Optionally set if the follow_class_name column value is specified.
+    follow_class_index BIGINT;
+BEGIN
+    -- Fetch the class's current value of depend_on_known_indirectly.
+    SELECT depend_on_known_indirectly INTO l_depend_on_known_indirectly
+        FROM dhcp6_client_class_order WHERE id = class_id;
+
+    -- Save it to the current session for use elsewhere during this transaction.
+    -- Note this does not work prior to Postgres 9.2 unless the variables are
+    -- defined in postgresql.conf. I think for now we put up with CB not supported
+    -- prior to 9.2 or we tell people how to edit the conf file.
+    PERFORM set_session_value('kea.depend_on_known_indirectly', l_depend_on_known_indirectly);
+
+    -- Bail if the class is updated without re-positioning.
+    IF(
+       l_depend_on_known_indirectly IS NOT NULL AND
+       ((new_follow_class_name IS NULL AND old_follow_class_name IS NULL) OR
+        (new_follow_class_name = old_follow_class_name))
+    ) THEN
+        -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+        -- whenever the dhcp6_client_class record is updated. Such update may include
+        -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+        -- This value will be later adjusted when dependencies are inserted.
+        -- TKM should we update the session value also or is it moot?
+        UPDATE dhcp6_client_class_order SET depend_on_known_indirectly = false
+            WHERE class_id = id;
+        RETURN;
+    END IF;
+
+    IF new_follow_class_name IS NOT NULL THEN
+        -- Get the position of the class after which the new class should be added.
+        SELECT o.order_index INTO follow_class_index
+            FROM dhcp6_client_class AS c
+            INNER JOIN dhcp6_client_class_order AS o
+                ON c.id = o.class_id
+            WHERE c.name = new_follow_class_name;
+
+        IF follow_class_index IS NULL THEN
+            -- The class with a name specified with new_follow_class_name does
+            -- not exist.
+            RAISE EXCEPTION 'Class %s does not exist.', new_follow_class_name
+                USING ERRCODE = 'sql_routine_exception';
+        END IF;
+
+        -- We need to place the new class at the position of follow_class_index + 1.
+        -- There may be a class at this position already.
+        IF EXISTS(SELECT * FROM dhcp6_client_class_order WHERE order_index = follow_class_index + 1) THEN
+            -- There is a class at this position already. Let's move all classes
+            -- starting from this position by one to create a spot for the new
+            -- class.
+            UPDATE dhcp6_client_class_order
+                SET order_index = order_index + 1
+            WHERE order_index >= follow_class_index + 1;
+            -- TKM postgresql doesn't like order by here, does it matter?
+            -- ORDER BY order_index DESC;
+        END IF;
+
+    ELSE
+        -- A caller did not specify the new_follow_class_name value. Let's append the
+        -- new class at the end of the hierarchy.
+        SELECT MAX(order_index) INTO follow_class_index FROM dhcp6_client_class_order;
+        IF follow_class_index IS NULL THEN
+            -- Apparently, there are no classes. Let's start from 0.
+            follow_class_index = 0;
+        END IF;
+    END IF;
+
+    -- Check if moving the class doesn't break dependent classes.
+    IF EXISTS(
+        SELECT 1 FROM dhcp6_client_class_dependency AS d
+            INNER JOIN dhcp6_client_class_order AS o
+                ON d.class_id = o.class_id
+            WHERE d.dependency_id = id AND o.order_index < follow_class_index + 1
+        LIMIT 1
+    ) THEN
+        RAISE EXCEPTION 'Unable to move class with id %s because it would break its dependencies', id
+            USING ERRCODE = 'sql_routine_exception';
+    END IF;
+
+    -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
+    -- whenever the dhcp6_client_class record is updated. Such update may include
+    -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
+    -- This value will be later adjusted when dependencies are inserted.
+    -- TKM - note that ON CONFLICT requires PostgreSQL 9.5 or later.
+    UPDATE dhcp6_client_class_order
+        SET order_index = follow_class_index + 1,
+            depend_on_known_indirectly = l_depend_on_known_indirectly
+        WHERE class_id = id;
+    IF FOUND THEN
+        RETURN;
+    END IF;
+
+    INSERT INTO  dhcp6_client_class_order(class_id, order_index, depend_on_known_indirectly)
+        VALUES (id, follow_class_index + 1, false);
+    RETURN;
+END;\$\$;
+
+-- Change primary key to composite, dependency table can have multiple rows
+-- per class id.
+ALTER TABLE dhcp4_client_class_dependency DROP CONSTRAINT dhcp4_client_class_dependency_pkey;
+ALTER TABLE dhcp4_client_class_dependency ADD PRIMARY KEY(class_id, dependency_id);
+
+ALTER TABLE dhcp6_client_class_dependency DROP CONSTRAINT dhcp6_client_class_dependency_pkey;
+ALTER TABLE dhcp6_client_class_dependency ADD PRIMARY KEY(class_id, dependency_id);
+
+-- Replace triggers that verify class dependency.
+-- Because they are BEFORE INSERT triggers they need to return NEW not NULL.
+-- -----------------------------------------------------------------------
+-- Trigger verifying if class dependency is met. It includes checking
+-- if referenced classes exist, are associated with the same server
+-- or all servers, and are defined before the class specified with
+-- class_id.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp4_client_class_check_dependency_BINS()
+    RETURNS trigger AS \$dhcp4_client_class_check_dependency_BINS\$
+BEGIN
+    PERFORM checkDHCPv4ClientClassDependency(NEW.class_id, NEW.dependency_id);
+    RETURN NEW;
+END;
+\$dhcp4_client_class_check_dependency_BINS\$
+LANGUAGE plpgsql;
+
+-- -----------------------------------------------------------------------
+-- Trigger verifying if class dependency is met. It includes checking
+-- if referenced classes exist, are associated with the same server
+-- or all servers, and are defined before the class specified with
+-- class_id.
+-- -----------------------------------------------------------------------
+CREATE OR REPLACE FUNCTION func_dhcp6_client_class_check_dependency_BINS()
+    RETURNS trigger AS \$dhcp6_client_class_check_dependency_BINS\$
+BEGIN
+    PERFORM checkDHCPv6ClientClassDependency(NEW.class_id, NEW.dependency_id);
+    RETURN NEW;
+END;
+\$dhcp6_client_class_check_dependency_BINS\$
+LANGUAGE plpgsql;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '10', minor = '0';
+
+-- This line concludes the schema upgrade to version 10.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_010_to_011.sh.in b/src/share/database/scripts/pgsql/upgrade_010_to_011.sh.in
new file mode 100644
index 0000000..1824a27
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_010_to_011.sh.in
@@ -0,0 +1,154 @@
+#!/bin/sh
+
+# Copyright (C) 2022-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "10.0" ]; then
+    printf 'This script upgrades 10.0 to 11.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 11.0.
+
+-- Replace createOptionAuditDHCP6() with a version corrected
+-- where clause when scope is 6 (i.e. PD pool)
+--
+-- -----------------------------------------------------
+--
+-- Stored procedure which updates modification timestamp of
+-- a parent object when an option is modified.
+--
+-- The following parameters are passed to the procedure:
+-- - modification_type: "create", "update" or "delete"
+-- - scope_id: identifier of the option scope, e.g.
+--   global, subnet specific etc. See dhcp_option_scope
+--   for specific values.
+-- - option_id: identifier of the option.
+-- - p_subnet_id: identifier of the subnet if the option
+--   belongs to the subnet.
+-- - host_id: identifier of the host if the option
+-- - belongs to the host.
+-- - network_name: shared network name if the option
+--   belongs to the shared network.
+-- - pool_id: identifier of the pool if the option
+--   belongs to the pool.
+-- - pd_pool_id: identifier of the pool if the option
+--   belongs to the pd pool.
+-- - p_modification_ts: modification timestamp of the
+--   option.
+--   Some arguments are prefixed with "p_" to avoid ambiguity
+--   with column names in SQL statements. PostgreSQL does not
+--   allow table aliases to be used with column names in update
+--   set expressions.
+-- -----------------------------------------------------
+CREATE OR REPLACE FUNCTION createOptionAuditDHCP6(modification_type VARCHAR,
+                                                  scope_id SMALLINT,
+                                                  option_id INT,
+                                                  p_subnet_id BIGINT,
+                                                  host_id INT,
+                                                  network_name VARCHAR,
+                                                  pool_id BIGINT,
+                                                  pd_pool_id BIGINT,
+                                                  p_modification_ts TIMESTAMP WITH TIME ZONE)
+RETURNS VOID
+LANGUAGE plpgsql
+AS \$\$
+DECLARE
+    -- These variables will hold shared network id and subnet id that
+    -- we will select.
+    snid BIGINT;
+    sid BIGINT;
+    cascade_transaction BOOLEAN;
+BEGIN
+    -- Cascade transaction flag is set to true to prevent creation of
+    -- the audit entries for the options when the options are
+    -- created as part of the parent object creation or update.
+    -- For example: when the option is added as part of the subnet
+    -- addition, the cascade transaction flag is equal to true. If
+    -- the option is added into the existing subnet the cascade
+    -- transaction is equal to false. Note that depending on the option
+    -- scope the audit entry will contain the object_type value
+    -- of the parent object to cause the server to replace the
+    -- entire subnet. The only case when the object_type will be
+    -- set to 'dhcp6_options' is when a global option is added.
+    -- Global options do not have the owner.
+
+    cascade_transaction := get_session_boolean('kea.cascade_transaction');
+    IF cascade_transaction = false THEN
+        -- todo: host manager hasn't been updated to use audit
+        -- mechanisms so ignore host specific options for now.
+        IF scope_id = 0 THEN
+            -- If a global option is added or modified, create audit
+            -- entry for the 'dhcp6_options' table.
+            PERFORM createAuditEntryDHCP6('dhcp6_options', option_id, modification_type);
+        ELSEIF scope_id = 1 THEN
+            -- If subnet specific option is added or modified, update
+            -- the modification timestamp of this subnet to allow the
+            -- servers to refresh the subnet information. This will
+            -- also result in creating an audit entry for this subnet.
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = p_subnet_id;
+        ELSEIF scope_id = 4 THEN
+            -- If shared network specific option is added or modified,
+            -- update the modification timestamp of this shared network
+            -- to allow the servers to refresh the shared network
+            -- information. This will also result in creating an
+            -- audit entry for this shared network.
+           SELECT id INTO snid FROM dhcp6_shared_network WHERE name = network_name LIMIT 1;
+           UPDATE dhcp6_shared_network SET modification_ts = p_modification_ts
+                WHERE id = snid;
+        ELSEIF scope_id = 5 THEN
+            -- If pool specific option is added or modified, update
+            -- the modification timestamp of the owning subnet.
+            SELECT dhcp6_pool.subnet_id INTO sid FROM dhcp6_pool WHERE id = pool_id;
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        ELSEIF scope_id = 6 THEN
+            -- If pd pool specific option is added or modified, create
+            -- audit entry for the subnet which this pool belongs to.
+            SELECT dhcp6_pd_pool.subnet_id INTO sid FROM dhcp6_pd_pool WHERE id = pd_pool_id;
+            UPDATE dhcp6_subnet SET modification_ts = p_modification_ts
+                WHERE subnet_id = sid;
+        END IF;
+    END IF;
+    RETURN;
+END;\$\$;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '11', minor = '0';
+
+-- This line concludes the schema upgrade to version 11.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_011_to_012.sh.in b/src/share/database/scripts/pgsql/upgrade_011_to_012.sh.in
new file mode 100644
index 0000000..dc03096
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_011_to_012.sh.in
@@ -0,0 +1,106 @@
+#!/bin/sh
+
+# Copyright (C) 2022-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "11.0" ]; then
+    printf 'This script upgrades 11.0 to 12.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 12.0.
+
+-- Modify shared-network-name foreign key constraint on dhcp4_subnet to not perform
+-- the update when the network is deleted the cascaded update will not execute
+-- dhcp4_subnet update trigger leaving the updated subnets without audit_entries.
+ALTER TABLE dhcp4_subnet
+    DROP CONSTRAINT fk_dhcp4_subnet_shared_network,
+    ADD CONSTRAINT fk_dhcp4_subnet_shared_network FOREIGN KEY (shared_network_name)
+         REFERENCES dhcp4_shared_network (name)
+         ON DELETE NO ACTION ON UPDATE NO ACTION;
+
+-- Modify BEFORE delete trigger function on dhcp4_shared_network to explicitly
+-- update dhcp4_subnets. This ensures there are audit entries for updated
+-- subnets.
+-- Trigger function for dhcp4_shared_network_BDEL called BEFORE DELETE on dhcp4_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp4_shared_network_BDEL() RETURNS TRIGGER AS \$dhcp4_shared_network_BDEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP4('dhcp4_shared_network', OLD.id, 'delete');
+    -- Explicitly update subnets now rather than via foreign key constraint, this ensures the
+    -- audit entries for subnets will preceded that of the shared-network, keeping the order
+    -- of the entries the same as they are for MySQL.
+    UPDATE dhcp4_subnet SET shared_network_name = NULL WHERE shared_network_name = OLD.name;
+    DELETE FROM dhcp4_options WHERE shared_network_name = OLD.name;
+    RETURN OLD;
+END;
+\$dhcp4_shared_network_BDEL\$
+LANGUAGE plpgsql;
+
+-- Modify shared-network-name foreign key constraint on dhcp6_subnet to not perform
+-- the update when the network is deleted the cascaded update will not execute
+-- dhcp6_subnet update trigger leaving the updated subnets without audit_entries.
+ALTER TABLE dhcp6_subnet
+    DROP CONSTRAINT fk_dhcp6_subnet_shared_network,
+    ADD CONSTRAINT fk_dhcp6_subnet_shared_network FOREIGN KEY (shared_network_name)
+         REFERENCES dhcp6_shared_network (name)
+         ON DELETE NO ACTION ON UPDATE NO ACTION;
+
+-- Modify BEFORE delete trigger function on dhcp6_shared_network to explicitly
+-- update dhcp6_subnets. This ensures there are audit entries for updated
+-- subnets.
+-- Trigger function for dhcp6_shared_network_BDEL called BEFORE DELETE on dhcp6_shared_network
+CREATE OR REPLACE FUNCTION func_dhcp6_shared_network_BDEL() RETURNS TRIGGER AS \$dhcp6_shared_network_BDEL\$
+BEGIN
+    PERFORM createAuditEntryDHCP6('dhcp6_shared_network', OLD.id, 'delete');
+    -- Explicitly update subnets now rather than via foreign key constraint, this ensures the
+    -- audit entries for subnets will preceded that of the shared-network, keeping the order
+    -- of the entries the same as they are for MySQL.
+    UPDATE dhcp6_subnet SET shared_network_name = NULL WHERE shared_network_name = OLD.name;
+    DELETE FROM dhcp6_options WHERE shared_network_name = OLD.name;
+    RETURN OLD;
+END;
+\$dhcp6_shared_network_BDEL\$
+LANGUAGE plpgsql;
+
+-- Add user_context column to client class tables.
+ALTER TABLE dhcp4_client_class ADD COLUMN user_context JSON DEFAULT NULL;
+ALTER TABLE dhcp6_client_class ADD COLUMN user_context JSON DEFAULT NULL;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '12', minor = '0';
+
+-- This line concludes the schema upgrade to version 12.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_012_to_013.sh.in b/src/share/database/scripts/pgsql/upgrade_012_to_013.sh.in
new file mode 100644
index 0000000..330d25b
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_012_to_013.sh.in
@@ -0,0 +1,681 @@
+#!/bin/sh
+
+# Copyright (C) 2022-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "12.0" ]; then
+    printf 'This script upgrades 12.0 to 12.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 13.0.
+
+-- JSON functions --
+
+-- Helper function that avoids a casting error when the string
+-- presumed to be in JSON format, is empty.
+CREATE OR REPLACE FUNCTION json_cast(IN json_candidate TEXT)
+RETURNS JSON
+AS \$\$
+BEGIN
+    IF LENGTH(json_candidate) = 0 THEN
+        RETURN '{}'::json;
+    END IF;
+    RETURN json_candidate::json;
+END;
+\$\$ LANGUAGE plpgsql;
+
+-- Function that establishes whether JSON functions are supported.
+-- They should be provided with PostgreSQL >= 9.4.
+CREATE OR REPLACE FUNCTION isJsonSupported()
+RETURNS BOOLEAN
+AS \$\$
+BEGIN
+    IF get_session_value('json_supported') IS NULL THEN
+        IF (SELECT proname FROM pg_proc WHERE proname = 'json_extract_path') = 'json_extract_path' THEN
+            PERFORM set_session_value('kea.json_supported', true);
+        ELSE
+            PERFORM set_session_value('kea.json_supported', false);
+        END IF;
+    END IF;
+    RETURN get_session_value('kea.json_supported');
+END
+\$\$ LANGUAGE plpgsql;
+
+-- Schema changes related to lease limiting start here. --
+
+-- Recreate the triggers that update the leaseX_stat tables as stored procedures. --
+
+CREATE OR REPLACE FUNCTION lease4_AINS_lease4_stat(IN new_state BIGINT,
+                                                   IN new_subnet_id BIGINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    IF new_state = 0 OR new_state = 1 THEN
+        -- Update the state count if it exists.
+        UPDATE lease4_stat SET leases = leases + 1
+            WHERE subnet_id = new_subnet_id AND state = new_state;
+
+        -- Insert the state count record if it does not exist.
+        IF NOT FOUND THEN
+            INSERT INTO lease4_stat VALUES (new_subnet_id, new_state, 1);
+        END IF;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease4_AUPD_lease4_stat(IN old_state BIGINT,
+                                                   IN old_subnet_id BIGINT,
+                                                   IN new_state BIGINT,
+                                                   IN new_subnet_id BIGINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    IF old_subnet_id != new_subnet_id OR old_state != new_state THEN
+        IF old_state = 0 OR old_state = 1 THEN
+            -- Decrement the old state count if record exists.
+            UPDATE lease4_stat
+                SET leases = GREATEST(leases - 1, 0)
+                WHERE subnet_id = old_subnet_id AND state = old_state;
+        END IF;
+
+        IF new_state = 0 OR new_state = 1 THEN
+            -- Increment the new state count if record exists.
+            UPDATE lease4_stat SET leases = leases + 1
+                WHERE subnet_id = new_subnet_id AND state = new_state;
+
+            -- Insert new state record if it does not exist.
+            IF NOT FOUND THEN
+                INSERT INTO lease4_stat VALUES (new_subnet_id, new_state, 1);
+            END IF;
+        END IF;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease4_ADEL_lease4_stat(IN old_state BIGINT,
+                                                   IN old_subnet_id BIGINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    IF old_state = 0 OR old_state = 1 THEN
+        -- Decrement the state count if record exists.
+        UPDATE lease4_stat
+            SET leases = GREATEST(leases - 1, 0)
+            WHERE subnet_id = old_subnet_id AND old_state = state;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_AINS_lease6_stat(IN new_state BIGINT,
+                                                   IN new_subnet_id BIGINT,
+                                                   IN new_lease_type SMALLINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    IF new_state = 0 OR new_state = 1 THEN
+        -- Update the state count if it exists.
+        UPDATE lease6_stat SET leases = leases + 1
+            WHERE subnet_id = new_subnet_id AND lease_type = new_lease_type
+            AND state = new_state;
+
+        -- Insert the state count record if it does not exist.
+        IF NOT FOUND THEN
+            INSERT INTO lease6_stat VALUES (new_subnet_id, new_lease_type, new_state, 1);
+        END IF;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_AUPD_lease6_stat(IN old_state BIGINT,
+                                                   IN old_subnet_id BIGINT,
+                                                   IN old_lease_type SMALLINT,
+                                                   IN new_state BIGINT,
+                                                   IN new_subnet_id BIGINT,
+                                                   IN new_lease_type SMALLINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    IF old_subnet_id != new_subnet_id OR
+       old_lease_type != new_lease_type OR
+       old_state != new_state THEN
+        IF old_state = 0 OR old_state = 1 THEN
+            -- Decrement the old state count if record exists.
+            UPDATE lease6_stat
+                SET leases = GREATEST(leases - 1, 0)
+                WHERE subnet_id = old_subnet_id AND lease_type = old_lease_type
+                AND state = old_state;
+        END IF;
+
+        IF new_state = 0 OR new_state = 1 THEN
+            -- Increment the new state count if record exists
+            UPDATE lease6_stat SET leases = leases + 1
+                WHERE subnet_id = new_subnet_id AND lease_type = new_lease_type
+                AND state = new_state;
+
+            -- Insert new state record if it does not exist
+            IF NOT FOUND THEN
+                INSERT INTO lease6_stat
+                VALUES (new_subnet_id, new_lease_type, new_state, 1);
+            END IF;
+        END IF;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_ADEL_lease6_stat(IN old_state BIGINT,
+                                                   IN old_subnet_id BIGINT,
+                                                   IN old_lease_type SMALLINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    IF old_state = 0 OR old_state = 1 THEN
+        -- Decrement the state count if record exists
+        UPDATE lease6_stat
+            SET leases = GREATEST(leases - 1, 0)
+            WHERE subnet_id = old_subnet_id AND lease_type = old_lease_type
+            AND state = old_state;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+-- Create tables that contain the number of active leases. --
+
+CREATE TABLE lease4_stat_by_client_class (
+    client_class VARCHAR(128) NOT NULL PRIMARY KEY,
+    leases BIGINT NOT NULL
+);
+
+CREATE TABLE lease6_stat_by_client_class (
+    client_class VARCHAR(128) NOT NULL,
+    lease_type SMALLINT NOT NULL,
+    leases BIGINT NOT NULL,
+    PRIMARY KEY (client_class, lease_type),
+    CONSTRAINT fk_lease6_stat_by_client_class_lease_type FOREIGN KEY (lease_type)
+        REFERENCES lease6_types (lease_type)
+);
+
+-- Create procedures to be called for each row in after-event triggers for
+-- INSERT, UPDATE and DELETE on lease tables.
+
+CREATE OR REPLACE FUNCTION lease4_AINS_lease4_stat_by_client_class(IN new_state BIGINT,
+                                                                   IN new_user_context TEXT)
+RETURNS VOID
+AS \$\$
+DECLARE
+    class VARCHAR(128);
+BEGIN
+    -- Only state 0 is needed for lease limiting.
+    IF new_state = 0 THEN
+        -- Dive into client classes.
+        FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(new_user_context)->'ISC'->'client-classes') LOOP
+            SELECT TRIM('"' FROM class) INTO class;
+
+            -- Upsert to increment the lease count.
+            UPDATE lease4_stat_by_client_class SET leases = leases + 1
+                WHERE client_class = class;
+            IF NOT FOUND THEN
+                INSERT INTO lease4_stat_by_client_class VALUES (class, 1);
+            END IF;
+        END LOOP;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease4_AUPD_lease4_stat_by_client_class(IN old_state BIGINT,
+                                                                   IN old_user_context TEXT,
+                                                                   IN new_state BIGINT,
+                                                                   IN new_user_context TEXT)
+RETURNS VOID
+AS \$\$
+DECLARE
+    old_client_classes TEXT;
+    new_client_classes TEXT;
+    class VARCHAR(128);
+    length INT;
+    i INT;
+BEGIN
+    SELECT json_cast(old_user_context)->'ISC'->'client-classes' INTO old_client_classes;
+    SELECT json_cast(new_user_context)->'ISC'->'client-classes' INTO new_client_classes;
+
+    IF old_state != new_state OR old_client_classes != new_client_classes THEN
+        -- Check if it's moving away from a counted state.
+        IF old_state = 0 THEN
+            -- Dive into client classes.
+            FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(old_client_classes)) LOOP
+                SELECT TRIM('"' FROM class) INTO class;
+
+                -- Decrement the lease count if the record exists.
+                UPDATE lease4_stat_by_client_class SET leases = GREATEST(leases - 1, 0)
+                    WHERE client_class = class;
+            END LOOP;
+        END IF;
+
+        -- Check if it's moving into a counted state.
+        IF new_state = 0 THEN
+            -- Dive into client classes.
+            FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(new_client_classes)) LOOP
+                SELECT TRIM('"' FROM class) INTO class;
+
+                -- Upsert to increment the lease count.
+                UPDATE lease4_stat_by_client_class SET leases = leases + 1
+                    WHERE client_class = class;
+                IF NOT FOUND THEN
+                    INSERT INTO lease4_stat_by_client_class VALUES (class, 1);
+                END IF;
+            END LOOP;
+        END IF;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease4_ADEL_lease4_stat_by_client_class(IN old_state BIGINT,
+                                                                   IN old_user_context TEXT)
+RETURNS VOID
+AS \$\$
+DECLARE
+    class VARCHAR(128);
+BEGIN
+    -- Only state 0 is accounted for in lease limiting.
+    IF old_state = 0 THEN
+        -- Dive into client classes.
+        FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(old_user_context)->'ISC'->'client-classes') LOOP
+            SELECT TRIM('"' FROM class) INTO class;
+
+            -- Decrement the lease count if the record exists.
+            UPDATE lease4_stat_by_client_class SET leases = GREATEST(leases - 1, 0)
+                WHERE client_class = class;
+        END LOOP;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_AINS_lease6_stat_by_client_class(IN new_state BIGINT,
+                                                                   IN new_user_context TEXT,
+                                                                   IN new_lease_type SMALLINT)
+RETURNS VOID
+AS \$\$
+DECLARE
+    client_classes TEXT;
+    class VARCHAR(128);
+    length INT;
+    i INT;
+BEGIN
+    -- Only state 0 is needed for lease limiting.
+    IF new_state = 0 THEN
+        -- Dive into client classes.
+        FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(new_user_context)->'ISC'->'client-classes') LOOP
+            SELECT TRIM('"' FROM class) INTO class;
+
+            -- Upsert to increment the lease count.
+            UPDATE lease6_stat_by_client_class SET leases = leases + 1
+                WHERE client_class = class AND lease_type = new_lease_type;
+            IF NOT FOUND THEN
+                INSERT INTO lease6_stat_by_client_class VALUES (class, new_lease_type, 1);
+            END IF;
+        END LOOP;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_AUPD_lease6_stat_by_client_class(IN old_state BIGINT,
+                                                                   IN old_user_context TEXT,
+                                                                   IN old_lease_type SMALLINT,
+                                                                   IN new_state BIGINT,
+                                                                   IN new_user_context TEXT,
+                                                                   IN new_lease_type SMALLINT)
+RETURNS VOID
+AS \$\$
+DECLARE
+    old_client_classes TEXT;
+    new_client_classes TEXT;
+    class VARCHAR(128);
+    length INT;
+    i INT;
+BEGIN
+    SELECT json_cast(old_user_context)->'ISC'->'client-classes' INTO old_client_classes;
+    SELECT json_cast(new_user_context)->'ISC'->'client-classes' INTO new_client_classes;
+
+    IF old_state != new_state OR old_client_classes != new_client_classes OR old_lease_type != new_lease_type THEN
+        -- Check if it's moving away from a counted state.
+        IF old_state = 0 THEN
+            -- Dive into client classes.
+            FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(old_client_classes)) LOOP
+                SELECT TRIM('"' FROM class) INTO class;
+
+                -- Decrement the lease count if the record exists.
+                UPDATE lease6_stat_by_client_class SET leases = GREATEST(leases - 1, 0)
+                    WHERE client_class = class AND lease_type = old_lease_type;
+            END LOOP;
+        END IF;
+
+        -- Check if it's moving into a counted state.
+        IF new_state = 0 THEN
+            -- Dive into client classes.
+            FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(new_client_classes)) LOOP
+                SELECT TRIM('"' FROM class) INTO class;
+
+                -- Upsert to increment the lease count.
+                UPDATE lease6_stat_by_client_class SET leases = leases + 1
+                    WHERE client_class = class AND lease_type = new_lease_type;
+                IF NOT FOUND THEN
+                    INSERT INTO lease6_stat_by_client_class VALUES (class, new_lease_type, 1);
+                END IF;
+            END LOOP;
+        END IF;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_ADEL_lease6_stat_by_client_class(IN old_state BIGINT,
+                                                                   IN old_user_context TEXT,
+                                                                   IN old_lease_type SMALLINT)
+RETURNS VOID
+AS \$\$
+DECLARE
+    client_classes VARCHAR(1024);
+    class VARCHAR(128);
+    length INT;
+    i INT;
+BEGIN
+    -- Only state 0 is accounted for in lease limiting. But check both states to be consistent with lease6_stat.
+    IF old_state = 0 THEN
+        -- Dive into client classes.
+        FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(old_user_context)->'ISC'->'client-classes') LOOP
+            SELECT TRIM('"' FROM class) INTO class;
+
+            -- Decrement the lease count if the record exists.
+            UPDATE lease6_stat_by_client_class SET leases = GREATEST(leases - 1, 0)
+                WHERE client_class = class AND lease_type = old_lease_type;
+        END LOOP;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+-- Recreate the after-event triggers for INSERT, UPDATE and DELETE on lease tables to call the --
+-- stored procedures above in pairs of two: for client classes and for subnets. --
+
+DROP TRIGGER IF EXISTS stat_lease4_insert ON lease4;
+
+CREATE OR REPLACE FUNCTION func_lease4_AINS()
+RETURNS trigger AS \$lease4_AINS\$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease4_AINS_lease4_stat_by_client_class(NEW.state, NEW.user_context);
+    END IF;
+    PERFORM lease4_AINS_lease4_stat(NEW.state, NEW.subnet_id);
+    RETURN NULL;
+END;
+\$lease4_AINS\$ LANGUAGE plpgsql;
+
+CREATE TRIGGER lease4_AINS AFTER INSERT ON lease4
+    FOR EACH ROW EXECUTE PROCEDURE func_lease4_AINS();
+
+DROP TRIGGER IF EXISTS stat_lease4_update ON lease4;
+
+CREATE OR REPLACE FUNCTION func_lease4_AUPD()
+RETURNS trigger AS \$lease4_AUPD\$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease4_AUPD_lease4_stat_by_client_class(OLD.state, OLD.user_context, NEW.state, NEW.user_context);
+    END IF;
+    PERFORM lease4_AUPD_lease4_stat(OLD.state, OLD.subnet_id, NEW.state, NEW.subnet_id);
+    RETURN NULL;
+END;
+\$lease4_AUPD\$ LANGUAGE plpgsql;
+
+CREATE TRIGGER lease4_AUPD AFTER UPDATE ON lease4
+    FOR EACH ROW EXECUTE PROCEDURE func_lease4_AUPD();
+
+DROP TRIGGER IF EXISTS stat_lease4_delete ON lease4;
+
+CREATE OR REPLACE FUNCTION func_lease4_ADEL()
+RETURNS trigger AS \$lease4_ADEL\$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease4_ADEL_lease4_stat_by_client_class(OLD.state, OLD.user_context);
+    END IF;
+    PERFORM lease4_ADEL_lease4_stat(OLD.state, OLD.subnet_id);
+    RETURN NULL;
+END;
+\$lease4_ADEL\$ LANGUAGE plpgsql;
+
+CREATE TRIGGER lease4_ADEL AFTER DELETE ON lease4
+    FOR EACH ROW EXECUTE PROCEDURE func_lease4_ADEL();
+
+DROP TRIGGER IF EXISTS stat_lease6_insert ON lease6;
+
+CREATE OR REPLACE FUNCTION func_lease6_AINS()
+RETURNS trigger AS \$lease6_AINS\$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease6_AINS_lease6_stat_by_client_class(NEW.state, NEW.user_context, NEW.lease_type);
+    END IF;
+    PERFORM lease6_AINS_lease6_stat(NEW.state, NEW.subnet_id, NEW.lease_type);
+    RETURN NULL;
+END;
+\$lease6_AINS\$ LANGUAGE plpgsql;
+
+CREATE TRIGGER lease6_AINS AFTER INSERT ON lease6
+    FOR EACH ROW EXECUTE PROCEDURE func_lease6_AINS();
+
+DROP TRIGGER IF EXISTS stat_lease6_update ON lease6;
+
+CREATE OR REPLACE FUNCTION func_lease6_AUPD()
+RETURNS trigger AS \$lease6_AUPD\$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease6_AUPD_lease6_stat_by_client_class(OLD.state, OLD.user_context, OLD.lease_type, NEW.state, NEW.user_context, NEW.lease_type);
+    END IF;
+    PERFORM lease6_AUPD_lease6_stat(OLD.state, OLD.subnet_id, OLD.lease_type, NEW.state, NEW.subnet_id, NEW.lease_type);
+    RETURN NULL;
+END;
+\$lease6_AUPD\$ LANGUAGE plpgsql;
+
+CREATE TRIGGER lease6_AUPD AFTER UPDATE ON lease6
+    FOR EACH ROW EXECUTE PROCEDURE func_lease6_AUPD();
+
+DROP TRIGGER IF EXISTS stat_lease6_delete ON lease6;
+
+CREATE OR REPLACE FUNCTION func_lease6_ADEL()
+RETURNS trigger AS \$lease6_ADEL\$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease6_ADEL_lease6_stat_by_client_class(OLD.state, OLD.user_context, OLD.lease_type);
+    END IF;
+    PERFORM lease6_ADEL_lease6_stat(OLD.state, OLD.subnet_id, OLD.lease_type);
+    RETURN NULL;
+END;
+\$lease6_ADEL\$ LANGUAGE plpgsql;
+
+CREATE TRIGGER lease6_ADEL AFTER DELETE ON lease6
+    FOR EACH ROW EXECUTE PROCEDURE func_lease6_ADEL();
+
+-- Create functions that return an empty TEXT if all limits allow for more leases, or otherwise a
+-- TEXT in one of the following JSON formats detailing the limit that was reached:
+-- { "limit-type": "client-class", "name": foo, "lease-type": "address", "limit": 2, "count": 2 }
+-- { "limit-type": "subnet", "id": 1, "lease-type": "IA_PD", "limit": 2, "count": 2 }
+-- The following format for user_context is assumed:
+-- { "ISC": { "limits": { "client-classes": [ { "name": "foo", "address-limit": 2, "prefix-limit": 1 } ],
+--                        "subnet": { "id": 1, "address-limit": 2, "prefix-limit": 1 } } } }
+
+CREATE OR REPLACE FUNCTION checkLease4Limits(user_context TEXT)
+RETURNS TEXT
+AS \$\$
+DECLARE
+    class TEXT;
+    name VARCHAR(255);
+    sid INT;
+    lease_limit INT;
+    lease_count INT;
+BEGIN
+    -- Dive into client class limits.
+    FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(user_context)->'ISC'->'limits'->'client-classes') LOOP
+        SELECT TRIM('"' FROM (json_cast(class)->'name')::text) INTO name;
+        SELECT json_cast(class)->'address-limit' INTO lease_limit;
+
+        IF lease_limit IS NOT NULL THEN
+            -- Get the lease count for this client class.
+            SELECT leases FROM lease4_stat_by_client_class INTO lease_count WHERE client_class = name;
+            IF lease_count IS NULL THEN
+                lease_count := 0;
+            END IF;
+
+            -- Compare. Return immediately if the limit is surpassed.
+            IF lease_limit <= lease_count THEN
+                RETURN CONCAT('address limit ', lease_limit, ' for client class "', name, '", current lease count ', lease_count);
+            END IF;
+        END IF;
+    END LOOP;
+
+    -- Dive into subnet limits.
+    SELECT json_cast(user_context)->'ISC'->'limits'->'subnet'->'id' INTO sid;
+    SELECT json_cast(user_context)->'ISC'->'limits'->'subnet'->'address-limit' INTO lease_limit;
+
+    IF lease_limit IS NOT NULL THEN
+        -- Get the lease count for this client class.
+        SELECT leases FROM lease4_stat WHERE subnet_id = sid AND state = 0 INTO lease_count;
+        IF lease_count IS NULL THEN
+            lease_count := 0;
+        END IF;
+
+        -- Compare. Return immediately if the limit is surpassed.
+        IF lease_limit <= lease_count THEN
+            RETURN CONCAT('address limit ', lease_limit, ' for subnet ID ', sid, ', current lease count ', lease_count);
+        END IF;
+    END IF;
+
+    RETURN '';
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION checkLease6Limits(user_context TEXT)
+RETURNS TEXT
+AS \$\$
+DECLARE
+    class TEXT;
+    name VARCHAR(255);
+    sid INT;
+    lease_limit INT;
+    lease_count INT;
+BEGIN
+    -- Dive into client class limits.
+    FOR class IN SELECT * FROM JSON_ARRAY_ELEMENTS(json_cast(user_context)->'ISC'->'limits'->'client-classes') LOOP
+        SELECT TRIM('"' FROM (json_cast(class)->'name')::text) INTO name;
+        SELECT json_cast(class)->'address-limit' INTO lease_limit;
+
+        IF lease_limit IS NOT NULL THEN
+            -- Get the address count for this client class.
+            SELECT leases FROM lease6_stat_by_client_class WHERE client_class = name AND lease_type = 0 INTO lease_count;
+            IF lease_count IS NULL THEN
+                lease_count := 0;
+            END IF;
+
+            -- Compare. Return immediately if the limit is surpassed.
+            IF lease_limit <= lease_count THEN
+                RETURN CONCAT('address limit ', lease_limit, ' for client class "', name, '", current lease count ', lease_count);
+            END IF;
+        END IF;
+
+        SELECT json_cast(class)->'prefix-limit' INTO lease_limit;
+        IF lease_limit IS NOT NULL THEN
+            -- Get the prefix count for this client class.
+            SELECT leases FROM lease6_stat_by_client_class WHERE client_class = name AND lease_type = 2 INTO lease_count;
+            IF lease_count IS NULL THEN
+                lease_count := 0;
+            END IF;
+
+            -- Compare. Return immediately if the limit is surpassed.
+            IF lease_limit <= lease_count THEN
+                RETURN CONCAT('prefix limit ', lease_limit, ' for client class "', name, '", current lease count ', lease_count);
+            END IF;
+        END IF;
+    END LOOP;
+
+    -- Dive into subnet limits.
+    SELECT json_cast(user_context)->'ISC'->'limits'->'subnet'->'id' INTO sid;
+    SELECT json_cast(user_context)->'ISC'->'limits'->'subnet'->'address-limit' INTO lease_limit;
+    IF lease_limit IS NOT NULL THEN
+        -- Get the lease count for this subnet.
+        SELECT leases FROM lease6_stat WHERE subnet_id = sid AND lease_type = 0 AND state = 0 INTO lease_count;
+        IF lease_count IS NULL THEN
+            lease_count := 0;
+        END IF;
+
+        -- Compare. Return immediately if the limit is surpassed.
+        IF lease_limit <= lease_count THEN
+            RETURN CONCAT('address limit ', lease_limit, ' for subnet ID ', sid, ', current lease count ', lease_count);
+        END IF;
+    END IF;
+    SELECT json_cast(user_context)->'ISC'->'limits'->'subnet'->'prefix-limit' INTO lease_limit;
+    IF lease_limit IS NOT NULL THEN
+        -- Get the lease count for this client class.
+        SELECT leases FROM lease6_stat WHERE subnet_id = sid AND lease_type = 2 AND state = 0 INTO lease_count;
+        IF lease_count IS NULL THEN
+            lease_count := 0;
+        END IF;
+
+        -- Compare. Return immediately if the limit is surpassed.
+        IF lease_limit <= lease_count THEN
+            RETURN CONCAT('prefix limit ', lease_limit, ' for subnet ID ', sid, ', current lease count ', lease_count);
+        END IF;
+    END IF;
+
+    RETURN '';
+END;
+\$\$ LANGUAGE plpgsql;
+
+-- Improve hosts indexes for better performance of global reservations
+-- Create new index that uses only dhcp_identifier.
+CREATE INDEX key_dhcp_identifier on hosts (dhcp_identifier, dhcp_identifier_type);
+
+-- Modify existing indexes to include subnet_id values of 0, so index is also used
+-- for global reservations.
+DROP INDEX IF EXISTS key_dhcp4_identifier_subnet_id;
+CREATE UNIQUE INDEX key_dhcp4_identifier_subnet_id ON hosts
+        (dhcp_identifier ASC, dhcp_identifier_type ASC, dhcp4_subnet_id ASC)
+    WHERE (dhcp4_subnet_id IS NOT NULL);
+
+DROP INDEX IF EXISTS key_dhcp6_identifier_subnet_id;
+CREATE UNIQUE INDEX key_dhcp6_identifier_subnet_id ON hosts
+        (dhcp_identifier ASC, dhcp_identifier_type ASC, dhcp6_subnet_id ASC)
+    WHERE (dhcp6_subnet_id IS NOT NULL);
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '13', minor = '0';
+
+-- This line concludes the schema upgrade to version 13.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_013_to_014.sh.in b/src/share/database/scripts/pgsql/upgrade_013_to_014.sh.in
new file mode 100644
index 0000000..4c13e2d
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_013_to_014.sh.in
@@ -0,0 +1,65 @@
+#!/bin/sh
+
+# Copyright (C) 2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "13.0" ]; then
+    printf 'This script upgrades 13.0 to 14.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 14.0.
+
+-- Add cancelled (aka never-send) column to option tables.
+
+ALTER TABLE dhcp4_options ADD COLUMN cancelled BOOLEAN NOT NULL DEFAULT 'f';
+ALTER TABLE dhcp6_options ADD COLUMN cancelled BOOLEAN NOT NULL DEFAULT 'f';
+
+-- Add offer_lifetime column to v4 tables.
+ALTER TABLE dhcp4_shared_network
+    ADD COLUMN offer_lifetime BIGINT DEFAULT NULL;
+
+ALTER TABLE dhcp4_subnet
+    ADD COLUMN offer_lifetime BIGINT DEFAULT NULL;
+
+ALTER TABLE dhcp4_client_class
+    ADD COLUMN offer_lifetime BIGINT DEFAULT NULL;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '14', minor = '0';
+
+-- This line concludes the schema upgrade to version 14.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_014_to_015.sh.in b/src/share/database/scripts/pgsql/upgrade_014_to_015.sh.in
new file mode 100644
index 0000000..340845b
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_014_to_015.sh.in
@@ -0,0 +1,62 @@
+#!/bin/sh
+
+# Copyright (C) 2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "14.0" ]; then
+    printf 'This script upgrades 14.0 to 15.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 15.0.
+
+-- Add relay and remote id columns to DHCPv4 leases.
+--
+-- Note: these columns are only used for indexes, in particular they are
+-- not exported by lease4 dump as values are also in the user context
+ALTER TABLE lease4
+    ADD COLUMN relay_id BYTEA DEFAULT NULL,
+    ADD COLUMN remote_id BYTEA DEFAULT NULL;
+
+-- Create relay and remote id indexes.
+CREATE INDEX lease4_by_relay_id ON lease4 (relay_id);
+CREATE INDEX lease4_by_remote_id ON lease4 (remote_id);
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '15', minor = '0';
+
+-- This line concludes the schema upgrade to version 15.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_015_to_016.sh.in b/src/share/database/scripts/pgsql/upgrade_015_to_016.sh.in
new file mode 100644
index 0000000..826cd69
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_015_to_016.sh.in
@@ -0,0 +1,62 @@
+#!/bin/sh
+
+# Copyright (C) 2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "15.0" ]; then
+    printf 'This script upgrades 15.0 to 16.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 16.0.
+
+-- Add the allocator column to the DHCPv4 tables.
+ALTER TABLE dhcp4_subnet ADD COLUMN allocator TEXT DEFAULT NULL;
+ALTER TABLE dhcp4_shared_network ADD COLUMN allocator TEXT DEFAULT NULL;
+
+-- Add allocator and pd_allocator to the DHCPv6 subnet tables.
+ALTER TABLE dhcp6_subnet ADD COLUMN allocator TEXT DEFAULT NULL;
+ALTER TABLE dhcp6_subnet ADD COLUMN pd_allocator TEXT DEFAULT NULL;
+
+-- Add allocator and pd_allocator to the DHCPv6 shared network tables.
+ALTER TABLE dhcp6_shared_network ADD COLUMN allocator TEXT DEFAULT NULL;
+ALTER TABLE dhcp6_shared_network ADD COLUMN pd_allocator TEXT DEFAULT NULL;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '16', minor = '0';
+
+-- This line concludes the schema upgrade to version 16.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_016_to_017.sh.in b/src/share/database/scripts/pgsql/upgrade_016_to_017.sh.in
new file mode 100644
index 0000000..845e9ea
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_016_to_017.sh.in
@@ -0,0 +1,545 @@
+#!/bin/sh
+
+# Copyright (C) 2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "16.0" ]; then
+    printf 'This script upgrades 16.0 to 17.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+START TRANSACTION;
+
+-- This line starts the schema upgrade to version 17.0.
+
+UPDATE lease6 SET duid = E'\\\\x000000' WHERE duid = E'\\\\x00';
+
+-- Add pool_id column to the lease4 table.
+ALTER TABLE lease4
+    ADD COLUMN pool_id BIGINT NOT NULL DEFAULT 0;
+
+-- Add pool_id column to the lease6 table.
+ALTER TABLE lease6
+    ADD COLUMN pool_id BIGINT NOT NULL DEFAULT 0;
+
+-- Create v4 lease statistics table
+CREATE TABLE lease4_pool_stat (
+    subnet_id BIGINT NOT NULL,
+    pool_id BIGINT NOT NULL,
+    state INT8 NOT NULL,
+    leases BIGINT,
+    PRIMARY KEY (subnet_id, pool_id, state)
+);
+
+-- Create v6 lease statistics table
+CREATE TABLE lease6_pool_stat (
+    subnet_id BIGINT NOT NULL,
+    pool_id BIGINT NOT NULL,
+    lease_type SMALLINT NOT NULL,
+    state INT8 NOT NULL,
+    leases BIGINT,
+    PRIMARY KEY (subnet_id, pool_id, lease_type, state)
+);
+
+CREATE OR REPLACE FUNCTION lease4_AINS_lease4_pool_stat(IN new_state BIGINT,
+                                                        IN new_subnet_id BIGINT,
+                                                        IN new_pool_id BIGINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    IF new_state = 0 OR new_state = 1 THEN
+        -- Update the state count if it exists.
+        UPDATE lease4_pool_stat SET leases = leases + 1
+            WHERE subnet_id = new_subnet_id AND pool_id = new_pool_id
+            AND state = new_state;
+
+        -- Insert the state count record if it does not exist.
+        IF NOT FOUND THEN
+            INSERT INTO lease4_pool_stat
+            VALUES (new_subnet_id, new_pool_id, new_state, 1);
+        END IF;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease4_AUPD_lease4_pool_stat(IN old_state BIGINT,
+                                                        IN old_subnet_id BIGINT,
+                                                        IN old_pool_id BIGINT,
+                                                        IN new_state BIGINT,
+                                                        IN new_subnet_id BIGINT,
+                                                        IN new_pool_id BIGINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    IF old_subnet_id != new_subnet_id OR
+       old_pool_id != new_pool_id OR
+       old_state != new_state THEN
+        IF old_state = 0 OR old_state = 1 THEN
+            -- Decrement the old state count if record exists.
+            UPDATE lease4_pool_stat
+                SET leases = GREATEST(leases - 1, 0)
+                WHERE subnet_id = old_subnet_id AND pool_id = old_pool_id
+                AND state = old_state;
+        END IF;
+
+        IF new_state = 0 OR new_state = 1 THEN
+            -- Increment the new state count if record exists.
+            UPDATE lease4_pool_stat SET leases = leases + 1
+                WHERE subnet_id = new_subnet_id AND pool_id = new_pool_id
+                AND state = new_state;
+
+            -- Insert new state record if it does not exist.
+            IF NOT FOUND THEN
+                INSERT INTO lease4_pool_stat
+                VALUES (new_subnet_id, new_pool_id, new_state, 1);
+            END IF;
+        END IF;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease4_ADEL_lease4_pool_stat(IN old_state BIGINT,
+                                                        IN old_subnet_id BIGINT,
+                                                        IN old_pool_id BIGINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    IF old_state = 0 OR old_state = 1 THEN
+        -- Decrement the state count if record exists.
+        UPDATE lease4_pool_stat
+            SET leases = GREATEST(leases - 1, 0)
+            WHERE subnet_id = old_subnet_id AND pool_id = old_pool_id
+            AND state = old_state;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_AINS_lease6_pool_stat(IN new_state BIGINT,
+                                                        IN new_subnet_id BIGINT,
+                                                        IN new_pool_id BIGINT,
+                                                        IN new_lease_type SMALLINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    IF new_state = 0 OR new_state = 1 THEN
+        -- Update the state count if it exists.
+        UPDATE lease6_pool_stat SET leases = leases + 1
+            WHERE subnet_id = new_subnet_id AND pool_id = new_pool_id
+            AND lease_type = new_lease_type AND state = new_state;
+
+        -- Insert the state count record if it does not exist.
+        IF NOT FOUND THEN
+            INSERT INTO lease6_pool_stat
+            VALUES (new_subnet_id, new_pool_id, new_lease_type, new_state, 1);
+        END IF;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_AUPD_lease6_pool_stat(IN old_state BIGINT,
+                                                        IN old_subnet_id BIGINT,
+                                                        IN old_pool_id BIGINT,
+                                                        IN old_lease_type SMALLINT,
+                                                        IN new_state BIGINT,
+                                                        IN new_subnet_id BIGINT,
+                                                        IN new_pool_id BIGINT,
+                                                        IN new_lease_type SMALLINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    IF old_subnet_id != new_subnet_id OR
+       old_pool_id != new_pool_id OR
+       old_lease_type != new_lease_type OR
+       old_state != new_state THEN
+        IF old_state = 0 OR old_state = 1 THEN
+            -- Decrement the old state count if record exists.
+            UPDATE lease6_pool_stat
+                SET leases = GREATEST(leases - 1, 0)
+                WHERE subnet_id = old_subnet_id AND pool_id = old_pool_id
+                AND lease_type = old_lease_type AND state = old_state;
+        END IF;
+
+        IF new_state = 0 OR new_state = 1 THEN
+            -- Increment the new state count if record exists
+            UPDATE lease6_pool_stat SET leases = leases + 1
+                WHERE subnet_id = new_subnet_id AND pool_id = new_pool_id
+                AND lease_type = new_lease_type AND state = new_state;
+
+            -- Insert new state record if it does not exist
+            IF NOT FOUND THEN
+                INSERT INTO lease6_pool_stat
+                VALUES (new_subnet_id, new_pool_id, new_lease_type, new_state, 1);
+            END IF;
+        END IF;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION lease6_ADEL_lease6_pool_stat(IN old_state BIGINT,
+                                                        IN old_subnet_id BIGINT,
+                                                        IN old_pool_id BIGINT,
+                                                        IN old_lease_type SMALLINT)
+RETURNS VOID
+AS \$\$
+BEGIN
+    IF old_state = 0 OR old_state = 1 THEN
+        -- Decrement the state count if record exists
+        UPDATE lease6_pool_stat
+            SET leases = GREATEST(leases - 1, 0)
+            WHERE subnet_id = old_subnet_id AND pool_id = old_pool_id
+            AND lease_type = old_lease_type AND state = old_state;
+    END IF;
+END;
+\$\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION func_lease4_AINS()
+RETURNS trigger AS \$lease4_AINS\$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease4_AINS_lease4_stat_by_client_class(NEW.state, NEW.user_context);
+    END IF;
+    PERFORM lease4_AINS_lease4_stat(NEW.state, NEW.subnet_id);
+    PERFORM lease4_AINS_lease4_pool_stat(NEW.state, NEW.subnet_id, NEW.pool_id);
+    RETURN NULL;
+END;
+\$lease4_AINS\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION func_lease4_AUPD()
+RETURNS trigger AS \$lease4_AUPD\$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease4_AUPD_lease4_stat_by_client_class(OLD.state, OLD.user_context, NEW.state, NEW.user_context);
+    END IF;
+    PERFORM lease4_AUPD_lease4_stat(OLD.state, OLD.subnet_id, NEW.state, NEW.subnet_id);
+    PERFORM lease4_AUPD_lease4_pool_stat(OLD.state, OLD.subnet_id, OLD.pool_id, NEW.state, NEW.subnet_id, NEW.pool_id);
+    RETURN NULL;
+END;
+\$lease4_AUPD\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION func_lease4_ADEL()
+RETURNS trigger AS \$lease4_ADEL\$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease4_ADEL_lease4_stat_by_client_class(OLD.state, OLD.user_context);
+    END IF;
+    PERFORM lease4_ADEL_lease4_stat(OLD.state, OLD.subnet_id);
+    PERFORM lease4_ADEL_lease4_pool_stat(OLD.state, OLD.subnet_id, OLD.pool_id);
+    RETURN NULL;
+END;
+\$lease4_ADEL\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION func_lease6_AINS()
+RETURNS trigger AS \$lease6_AINS\$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease6_AINS_lease6_stat_by_client_class(NEW.state, NEW.user_context, NEW.lease_type);
+    END IF;
+    PERFORM lease6_AINS_lease6_stat(NEW.state, NEW.subnet_id, NEW.lease_type);
+    PERFORM lease6_AINS_lease6_pool_stat(NEW.state, NEW.subnet_id, NEW.pool_id, NEW.lease_type);
+    RETURN NULL;
+END;
+\$lease6_AINS\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION func_lease6_AUPD()
+RETURNS trigger AS \$lease6_AUPD\$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease6_AUPD_lease6_stat_by_client_class(OLD.state, OLD.user_context, OLD.lease_type, NEW.state, NEW.user_context, NEW.lease_type);
+    END IF;
+    PERFORM lease6_AUPD_lease6_stat(OLD.state, OLD.subnet_id, OLD.lease_type, NEW.state, NEW.subnet_id, NEW.lease_type);
+    PERFORM lease6_AUPD_lease6_pool_stat(OLD.state, OLD.subnet_id, OLD.pool_id, OLD.lease_type, NEW.state, NEW.subnet_id, NEW.pool_id, NEW.lease_type);
+    RETURN NULL;
+END;
+\$lease6_AUPD\$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION func_lease6_ADEL()
+RETURNS trigger AS \$lease6_ADEL\$
+BEGIN
+    IF isJsonSupported() = true THEN
+        PERFORM lease6_ADEL_lease6_stat_by_client_class(OLD.state, OLD.user_context, OLD.lease_type);
+    END IF;
+    PERFORM lease6_ADEL_lease6_stat(OLD.state, OLD.subnet_id, OLD.lease_type);
+    PERFORM lease6_ADEL_lease6_pool_stat(OLD.state, OLD.subnet_id, OLD.pool_id, OLD.lease_type);
+    RETURN NULL;
+END;
+\$lease6_ADEL\$ LANGUAGE plpgsql;
+
+DROP FUNCTION IF EXISTS lease4DumpHeader();
+CREATE OR REPLACE FUNCTION lease4DumpHeader()
+RETURNS text AS \$\$
+    select cast('address,hwaddr,client_id,valid_lifetime,expire,subnet_id,fqdn_fwd,fqdn_rev,hostname,state,user_context,pool_id' as text) as result;
+\$\$ LANGUAGE SQL;
+
+-- Adding support for pool ID in function to output a memfile-ready CSV file.
+-- Some columns that are SMALLINT in the lease4 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+DROP FUNCTION IF EXISTS lease4DumpData();
+CREATE OR REPLACE FUNCTION lease4DumpData()
+RETURNS TABLE (
+    address INET,
+    hwaddr VARCHAR,
+    client_id VARCHAR,
+    valid_lifetime BIGINT,
+    expire BIGINT,
+    subnet_id BIGINT,
+    fqdn_fwd INT,
+    fqdn_rev INT,
+    hostname VARCHAR,
+    state INT8,
+    user_context VARCHAR,
+    pool_id BIGINT
+) AS \$\$
+    SELECT
+        ('0.0.0.0'::inet + address),
+        colonSeparatedHex(encode(hwaddr, 'hex')),
+        colonSeparatedHex(encode(client_id, 'hex')),
+        valid_lifetime,
+        extract(epoch from expire)::bigint,
+        subnet_id,
+        fqdn_fwd::int,
+        fqdn_rev::int,
+        replace(hostname, ',', '&#x2c'),
+        state,
+        replace(user_context, ',', '&#x2c'),
+        pool_id
+    FROM lease4
+    ORDER BY address;
+\$\$ LANGUAGE SQL;
+
+DROP FUNCTION IF EXISTS lease6DumpHeader();
+CREATE OR REPLACE FUNCTION lease6DumpHeader()
+RETURNS TEXT AS \$\$
+    SELECT CAST('address,duid,valid_lifetime,expire,subnet_id,pref_lifetime,lease_type,iaid,prefix_len,fqdn_fwd,fqdn_rev,hostname,hwaddr,state,user_context,hwtype,hwaddr_source,pool_id' AS TEXT) AS result;
+\$\$ LANGUAGE SQL;
+
+-- Adding support for pool ID in function to output a memfile-ready CSV file.
+-- Some columns that are SMALLINT in the lease6 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+DROP FUNCTION IF EXISTS lease6DumpData();
+CREATE OR REPLACE FUNCTION lease6DumpData()
+RETURNS TABLE (
+    address VARCHAR,
+    duid VARCHAR,
+    valid_lifetime BIGINT,
+    expire BIGINT,
+    subnet_id BIGINT,
+    pref_lifetime BIGINT,
+    lease_type SMALLINT,
+    iaid INT,
+    prefix_len SMALLINT,
+    fqdn_fwd INT,
+    fqdn_rev INT,
+    hostname VARCHAR,
+    hwaddr VARCHAR,
+    state INT8,
+    user_context VARCHAR,
+    hwtype SMALLINT,
+    hwaddr_source SMALLINT,
+    pool_id BIGINT
+) AS \$\$
+    SELECT
+        address,
+        colonSeparatedHex(encode(duid, 'hex')),
+        valid_lifetime,
+        extract(epoch from expire)::bigint,
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd::int,
+        fqdn_rev::int,
+        replace(hostname, ',', '&#x2c'),
+        colonSeparatedHex(encode(hwaddr, 'hex')),
+        state,
+        replace(user_context, ',', '&#x2c'),
+        hwtype,
+        hwaddr_source,
+        pool_id
+    FROM lease6
+    ORDER BY address;
+\$\$ LANGUAGE SQL;
+
+-- Adding support for pool id in function that inserts a v4 lease from memfile data.
+-- Some columns that are SMALLINT in the lease4 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+CREATE OR REPLACE FUNCTION lease4Upload(
+    IN address VARCHAR,
+    IN hwaddr VARCHAR,
+    IN client_id VARCHAR,
+    IN valid_lifetime BIGINT,
+    IN expire BIGINT,
+    IN subnet_id BIGINT,
+    IN fqdn_fwd INT,
+    IN fqdn_rev INT,
+    IN hostname VARCHAR,
+    IN state INT8,
+    IN user_context VARCHAR,
+    IN pool_id BIGINT
+) RETURNS VOID AS \$\$
+BEGIN
+    INSERT INTO lease4 (
+        address,
+        hwaddr,
+        client_id,
+        valid_lifetime,
+        expire,
+        subnet_id,
+        fqdn_fwd,
+        fqdn_rev,
+        hostname,
+        state,
+        user_context,
+        pool_id
+    ) VALUES (
+        address::inet - '0.0.0.0'::inet,
+        decode(replace(hwaddr, ':', ''), 'hex'),
+        decode(replace(client_id, ':', ''), 'hex'),
+        valid_lifetime,
+        to_timestamp(expire),
+        subnet_id,
+        fqdn_fwd::int::boolean,
+        fqdn_rev::int::boolean,
+        replace(hostname, '&#x2c', ','),
+        state,
+        replace(user_context, '&#x2c', ','),
+        pool_id
+    );
+END
+\$\$ LANGUAGE plpgsql;
+
+-- Adding support for pool id in function that inserts a v6 lease from memfile data.
+-- Some columns that are SMALLINT in the lease6 table have their type promoted
+-- to INT in the declaration of this function for backwards compatibility with
+-- PostgreSQL versions.
+CREATE OR REPLACE FUNCTION lease6Upload(
+    IN address VARCHAR,
+    IN duid VARCHAR,
+    IN valid_lifetime BIGINT,
+    IN expire BIGINT,
+    IN subnet_id BIGINT,
+    IN pref_lifetime BIGINT,
+    IN lease_type INT,
+    IN iaid INT,
+    IN prefix_len INT,
+    IN fqdn_fwd INT,
+    IN fqdn_rev INT,
+    IN hostname VARCHAR,
+    IN hwaddr VARCHAR,
+    IN state INT8,
+    IN user_context VARCHAR,
+    IN hwtype INT,
+    IN hwaddr_source INT,
+    IN pool_id BIGINT
+) RETURNS VOID AS \$\$
+BEGIN
+    INSERT INTO lease6 (
+        address,
+        duid,
+        valid_lifetime,
+        expire,
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd,
+        fqdn_rev,
+        hostname,
+        hwaddr,
+        state,
+        user_context,
+        hwtype,
+        hwaddr_source,
+        pool_id
+    ) VALUES (
+        address,
+        decode(replace(duid, ':', ''), 'hex'),
+        valid_lifetime,
+        to_timestamp(expire),
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd::int::boolean,
+        fqdn_rev::int::boolean,
+        replace(hostname, '&#x2c', ','),
+        decode(replace(hwaddr, ':', ''), 'hex'),
+        state,
+        replace(user_context, '&#x2c', ','),
+        hwtype,
+        hwaddr_source,
+        pool_id
+    );
+END
+\$\$ LANGUAGE plpgsql;
+
+INSERT INTO lease4_pool_stat (subnet_id, pool_id, state, leases)
+    SELECT subnet_id, pool_id, state, count(*) FROM lease4
+    WHERE state = 0 OR state = 1 GROUP BY subnet_id, pool_id, state;
+
+INSERT INTO lease6_pool_stat (subnet_id, pool_id, lease_type, state, leases)
+    SELECT subnet_id, pool_id, lease_type, state, count(*) FROM lease6
+    WHERE state = 0 OR state = 1 GROUP BY subnet_id, pool_id, lease_type, state;
+
+-- Add the binary version of the IPv6 address for v6 BLQ prefix filter.
+ALTER TABLE lease6
+    ADD COLUMN binaddr BYTEA DEFAULT NULL;
+CREATE INDEX lease6_by_binaddr ON lease6 (binaddr ASC);
+
+-- Create table for v6 BLQ by-relay-id.
+CREATE TABLE lease6_relay_id (
+    extended_info_id SERIAL PRIMARY KEY NOT NULL,
+    relay_id BYTEA NOT NULL,
+    lease_addr BYTEA NOT NULL);
+CREATE INDEX lease6_relay_id_by_id ON lease6_relay_id (relay_id, lease_addr ASC);
+CREATE INDEX lease6_relay_id_by_address ON lease6_relay_id (lease_addr);
+
+-- Create table for v6 BLQ by-remote-id.
+CREATE TABLE lease6_remote_id (
+    extended_info_id SERIAL PRIMARY KEY NOT NULL,
+    remote_id BYTEA NOT NULL,
+    lease_addr BYTEA NOT NULL);
+CREATE INDEX lease6_remote_id_by_id ON lease6_remote_id (remote_id, lease_addr ASC);
+CREATE INDEX lease6_remote_id_by_address ON lease6_remote_id (lease_addr);
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '17', minor = '0';
+
+-- This line concludes the schema upgrade to version 17.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/upgrade_017_to_018.sh.in b/src/share/database/scripts/pgsql/upgrade_017_to_018.sh.in
new file mode 100644
index 0000000..6b7b976
--- /dev/null
+++ b/src/share/database/scripts/pgsql/upgrade_017_to_018.sh.in
@@ -0,0 +1,169 @@
+#!/bin/sh
+
+# Copyright (C) 2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+VERSION=$(pgsql_version "$@")
+
+if [ "$VERSION" != "17.0" ]; then
+    printf 'This script upgrades 17.0 to 18.0. '
+    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
+    exit 0
+fi
+
+psql "$@" >/dev/null <<EOF
+
+-- This line starts the schema upgrade to version 18.0.
+
+-- Drop binaddr index and column from lease6.
+DROP INDEX lease6_by_binaddr;
+ALTER TABLE lease6
+    DROP COLUMN binaddr;
+
+-- Change lease6:address to INET.
+ALTER TABLE lease6 ALTER COLUMN address TYPE INET USING address::INET;
+
+-- Change ipv6_reservations:address to INET.
+ALTER TABLE ipv6_reservations ALTER COLUMN address TYPE INET USING address::INET;
+
+-- Invoke HOST() on address now that address type is inet
+CREATE OR REPLACE FUNCTION lease6DumpData()
+RETURNS TABLE (
+    address VARCHAR,
+    duid VARCHAR,
+    valid_lifetime BIGINT,
+    expire BIGINT,
+    subnet_id BIGINT,
+    pref_lifetime BIGINT,
+    lease_type SMALLINT,
+    iaid INT,
+    prefix_len SMALLINT,
+    fqdn_fwd INT,
+    fqdn_rev INT,
+    hostname VARCHAR,
+    hwaddr VARCHAR,
+    state INT8,
+    user_context VARCHAR,
+    hwtype SMALLINT,
+    hwaddr_source SMALLINT,
+    pool_id BIGINT
+) AS \$\$
+    SELECT
+        HOST(address),
+        colonSeparatedHex(encode(duid, 'hex')),
+        valid_lifetime,
+        extract(epoch from expire)::bigint,
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd::int,
+        fqdn_rev::int,
+        replace(hostname, ',', '&#x2c'),
+        colonSeparatedHex(encode(hwaddr, 'hex')),
+        state,
+        replace(user_context, ',', '&#x2c'),
+        hwtype,
+        hwaddr_source,
+        pool_id
+    FROM lease6
+    ORDER BY address;
+\$\$ LANGUAGE SQL;
+
+-- Invoke HOST() on address now that address type is inet
+CREATE OR REPLACE FUNCTION lease6Upload(
+    IN address VARCHAR,
+    IN duid VARCHAR,
+    IN valid_lifetime BIGINT,
+    IN expire BIGINT,
+    IN subnet_id BIGINT,
+    IN pref_lifetime BIGINT,
+    IN lease_type INT,
+    IN iaid INT,
+    IN prefix_len INT,
+    IN fqdn_fwd INT,
+    IN fqdn_rev INT,
+    IN hostname VARCHAR,
+    IN hwaddr VARCHAR,
+    IN state INT8,
+    IN user_context VARCHAR,
+    IN hwtype INT,
+    IN hwaddr_source INT,
+    IN pool_id BIGINT
+) RETURNS VOID AS \$\$
+BEGIN
+    INSERT INTO lease6 (
+        address,
+        duid,
+        valid_lifetime,
+        expire,
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd,
+        fqdn_rev,
+        hostname,
+        hwaddr,
+        state,
+        user_context,
+        hwtype,
+        hwaddr_source,
+        pool_id
+    ) VALUES (
+        cast(address as inet),
+        decode(replace(duid, ':', ''), 'hex'),
+        valid_lifetime,
+        to_timestamp(expire),
+        subnet_id,
+        pref_lifetime,
+        lease_type,
+        iaid,
+        prefix_len,
+        fqdn_fwd::int::boolean,
+        fqdn_rev::int::boolean,
+        replace(hostname, '&#x2c', ','),
+        decode(replace(hwaddr, ':', ''), 'hex'),
+        state,
+        replace(user_context, '&#x2c', ','),
+        hwtype,
+        hwaddr_source,
+        pool_id
+    );
+END
+\$\$ LANGUAGE plpgsql;
+
+-- Update the schema version number.
+UPDATE schema_version
+    SET version = '18', minor = '0';
+
+-- This line concludes the schema upgrade to version 18.0.
+
+-- Commit the script transaction.
+COMMIT;
+
+EOF
diff --git a/src/share/database/scripts/pgsql/wipe_data.sh.in b/src/share/database/scripts/pgsql/wipe_data.sh.in
new file mode 100644
index 0000000..7c9c637
--- /dev/null
+++ b/src/share/database/scripts/pgsql/wipe_data.sh.in
@@ -0,0 +1,122 @@
+#!/bin/sh
+
+# Copyright (C) 2019-2023 Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# This script is primarily used for MySQL unit tests, which need to
+# ensure an empty, but schema correct database for each test.  It
+# deletes ALL transient data from an existing Kea MySQL schema,
+# including leases, reservations, etc... Use at your own peril.
+# Reference tables will be left in-tact.
+
+# shellcheck disable=SC1091
+# SC1091: Not following: ... was not specified as input (see shellcheck -x).
+
+# Exit with error if commands exit with non-zero and if undefined variables are
+# used.
+set -eu
+
+# shellcheck disable=SC2034
+# SC2034: ... appears unused. Verify use (or export if used externally).
+prefix="@prefix@"
+
+# Include utilities. Use installed version if available and
+# use build version if it isn't.
+if test -f "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"; then
+    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
+else
+    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
+fi
+
+# First argument must be the expected schema version <major>.<minor>
+# Check if it's passed at all.
+if [ "$#" -lt "1" ]; then
+    printf "Required at least one parameter: schema version number, e.g. 7.0\n"
+    exit 1
+fi
+exp_version="$1"
+shift
+
+# Remaining arguments are used as pgsql command line arguments
+
+# If the existing schema doesn't match, the fail
+VERSION=$(pgsql_version "$@")
+if [ "$VERSION" = "" ]; then
+    printf "Cannot wipe data, schema version could not be detected.\n"
+    exit 1
+fi
+
+if [ "$VERSION" != "$exp_version" ]; then
+    printf 'Cannot wipe data, wrong schema version. '
+    printf 'Expected version %s, found %s.\n' "${exp_version}" "${VERSION}"
+    exit 1
+fi
+
+# Delete transient data from tables.  We're using delete instead
+# of truncate because it is much faster since our unit tests
+# create very little data.
+# Note we disable revision auditing to avoid issues with delete
+# triggers.
+psql "$@" >/dev/null <<EOF
+SELECT set_config('kea.disable_audit', 'true', false);
+START TRANSACTION;
+DELETE FROM hosts CASCADE;
+DELETE FROM dhcp4_options;
+DELETE FROM ipv6_reservations;
+DELETE FROM dhcp6_options;
+DELETE FROM lease4;
+DELETE FROM lease4_stat;
+DELETE FROM lease4_pool_stat;
+DELETE FROM lease6;
+DELETE FROM lease6_stat;
+DELETE FROM lease6_pool_stat;
+DELETE FROM logs;
+DELETE FROM lease4_stat_by_client_class;
+DELETE FROM lease6_stat_by_client_class;
+
+-- Config Backend tables
+DELETE FROM dhcp4_audit;
+DELETE FROM dhcp4_audit_revision;
+DELETE FROM dhcp4_global_parameter;
+DELETE FROM dhcp4_global_parameter_server;
+DELETE FROM dhcp4_option_def;
+DELETE FROM dhcp4_option_def_server;
+DELETE FROM dhcp4_options;
+DELETE FROM dhcp4_options_server;
+DELETE FROM dhcp4_pool;
+DELETE FROM dhcp4_shared_network;
+DELETE FROM dhcp4_subnet;
+DELETE FROM dhcp4_subnet_server;
+DELETE FROM dhcp4_shared_network_server;
+DELETE FROM dhcp4_client_class_order;
+DELETE FROM dhcp4_client_class_dependency;
+DELETE FROM dhcp4_client_class_server;
+DELETE FROM dhcp4_client_class;
+DELETE FROM dhcp4_server WHERE tag != 'all'; -- preserve the special tag
+
+DELETE FROM dhcp6_audit;
+DELETE FROM dhcp6_audit_revision;
+DELETE FROM dhcp6_global_parameter;
+DELETE FROM dhcp6_global_parameter_server;
+DELETE FROM dhcp6_option_def;
+DELETE FROM dhcp6_option_def_server;
+DELETE FROM dhcp6_options;
+DELETE FROM dhcp6_options_server;
+DELETE FROM dhcp6_pool;
+DELETE FROM dhcp6_pd_pool;
+DELETE FROM dhcp6_shared_network;
+DELETE FROM dhcp6_subnet;
+DELETE FROM dhcp6_client_class_order;
+DELETE FROM dhcp6_client_class_dependency;
+DELETE FROM dhcp6_client_class_server;
+DELETE FROM dhcp6_client_class;
+DELETE FROM dhcp6_server WHERE tag != 'all'; -- preserve the special tag
+
+DELETE FROM lease6_relay_id;
+DELETE FROM lease6_remote_id;
+
+COMMIT;
+EOF