Adding upstream version 13.4.upstream/13.4upstream

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

9 files changed, 2411 insertions, 0 deletions

diff --git a/contrib/fuzzystrmatch/.gitignore b/contrib/fuzzystrmatch/.gitignore
new file mode 100644
index 0000000..5dcb3ff
--- /dev/null
+++ b/contrib/fuzzystrmatch/.gitignore
@@ -0,0 +1,4 @@
+# Generated subdirectories
+/log/
+/results/
+/tmp_check/
diff --git a/contrib/fuzzystrmatch/Makefile b/contrib/fuzzystrmatch/Makefile
new file mode 100644
index 0000000..0704894
--- /dev/null
+++ b/contrib/fuzzystrmatch/Makefile
@@ -0,0 +1,24 @@
+# contrib/fuzzystrmatch/Makefile
+
+MODULE_big = fuzzystrmatch
+OBJS = \
+	$(WIN32RES) \
+	dmetaphone.o \
+	fuzzystrmatch.o
+
+EXTENSION = fuzzystrmatch
+DATA = fuzzystrmatch--1.1.sql fuzzystrmatch--1.0--1.1.sql
+PGFILEDESC = "fuzzystrmatch - similarities and distance between strings"
+
+REGRESS = fuzzystrmatch
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = contrib/fuzzystrmatch
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/contrib/fuzzystrmatch/dmetaphone.c b/contrib/fuzzystrmatch/dmetaphone.c
new file mode 100644
index 0000000..6f4d2b7
--- /dev/null
+++ b/contrib/fuzzystrmatch/dmetaphone.c
@@ -0,0 +1,1438 @@
+/*
+ * This is a port of the Double Metaphone algorithm for use in PostgreSQL.
+ *
+ * contrib/fuzzystrmatch/dmetaphone.c
+ *
+ * Double Metaphone computes 2 "sounds like" strings - a primary and an
+ * alternate. In most cases they are the same, but for foreign names
+ * especially they can be a bit different, depending on pronunciation.
+ *
+ * Information on using Double Metaphone can be found at
+ *	 http://www.codeproject.com/string/dmetaphone1.asp
+ * and the original article describing it can be found at
+ *	 http://drdobbs.com/184401251
+ *
+ * For PostgreSQL we provide 2 functions - one for the primary and one for
+ * the alternate. That way the functions are pure text->text mappings that
+ * are useful in functional indexes. These are 'dmetaphone' for the
+ * primary and 'dmetaphone_alt' for the alternate.
+ *
+ * Assuming that dmetaphone.so is in $libdir, the SQL to set up the
+ * functions looks like this:
+ *
+ * CREATE FUNCTION dmetaphone (text) RETURNS text
+ *	  LANGUAGE C IMMUTABLE STRICT
+ *	  AS '$libdir/dmetaphone', 'dmetaphone';
+ *
+ * CREATE FUNCTION dmetaphone_alt (text) RETURNS text
+ *	  LANGUAGE C IMMUTABLE STRICT
+ *	  AS '$libdir/dmetaphone', 'dmetaphone_alt';
+ *
+ * Note that you have to declare the functions IMMUTABLE if you want to
+ * use them in functional indexes, and you have to declare them as STRICT
+ * as they do not check for NULL input, and will segfault if given NULL input.
+ * (See below for alternative ) Declaring them as STRICT means PostgreSQL
+ * will never call them with NULL, but instead assume the result is NULL,
+ * which is what we (I) want.
+ *
+ * Alternatively, compile with -DDMETAPHONE_NOSTRICT and the functions
+ * will detect NULL input and return NULL. The you don't have to declare them
+ * as STRICT.
+ *
+ * There is a small inefficiency here - each function call actually computes
+ * both the primary and the alternate and then throws away the one it doesn't
+ * need. That's the way the perl module was written, because perl can handle
+ * a list return more easily than we can in PostgreSQL. The result has been
+ * fast enough for my needs, but it could maybe be optimized a bit to remove
+ * that behaviour.
+ *
+ */
+
+
+/***************************** COPYRIGHT NOTICES ***********************
+
+Most of this code is directly from the Text::DoubleMetaphone perl module
+version 0.05 available from https://www.cpan.org/.
+It bears this copyright notice:
+
+
+  Copyright 2000, Maurice Aubrey <maurice@hevanet.com>.
+  All rights reserved.
+
+  This code is based heavily on the C++ implementation by
+  Lawrence Philips and incorporates several bug fixes courtesy
+  of Kevin Atkinson <kevina@users.sourceforge.net>.
+
+  This module is free software; you may redistribute it and/or
+  modify it under the same terms as Perl itself.
+
+The remaining code is authored by Andrew Dunstan <amdunstan@ncshp.org> and
+<andrew@dunslane.net> and is covered this copyright:
+
+  Copyright 2003, North Carolina State Highway Patrol.
+  All rights reserved.
+
+  Permission to use, copy, modify, and distribute this software and its
+  documentation for any purpose, without fee, and without a written agreement
+  is hereby granted, provided that the above copyright notice and this
+  paragraph and the following two paragraphs appear in all copies.
+
+  IN NO EVENT SHALL THE NORTH CAROLINA STATE HIGHWAY PATROL BE LIABLE TO ANY
+  PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES,
+  INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
+  DOCUMENTATION, EVEN IF THE NORTH CAROLINA STATE HIGHWAY PATROL HAS BEEN
+  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+  THE NORTH CAROLINA STATE HIGHWAY PATROL SPECIFICALLY DISCLAIMS ANY
+  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED
+  HEREUNDER IS ON AN "AS IS" BASIS, AND THE NORTH CAROLINA STATE HIGHWAY PATROL
+  HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR
+  MODIFICATIONS.
+
+***********************************************************************/
+
+
+/* include these first, according to the docs */
+#ifndef DMETAPHONE_MAIN
+
+#include "postgres.h"
+
+#include "utils/builtins.h"
+
+/* turn off assertions for embedded function */
+#define NDEBUG
+
+#else							/* DMETAPHONE_MAIN */
+
+/* we need these if we didn't get them from postgres.h */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+
+#endif							/* DMETAPHONE_MAIN */
+
+#include <assert.h>
+#include <ctype.h>
+
+/* prototype for the main function we got from the perl module */
+static void DoubleMetaphone(char *, char **);
+
+#ifndef DMETAPHONE_MAIN
+
+/*
+ * The PostgreSQL visible dmetaphone function.
+ */
+
+PG_FUNCTION_INFO_V1(dmetaphone);
+
+Datum
+dmetaphone(PG_FUNCTION_ARGS)
+{
+	text	   *arg;
+	char	   *aptr,
+			   *codes[2],
+			   *code;
+
+#ifdef DMETAPHONE_NOSTRICT
+	if (PG_ARGISNULL(0))
+		PG_RETURN_NULL();
+#endif
+	arg = PG_GETARG_TEXT_PP(0);
+	aptr = text_to_cstring(arg);
+
+	DoubleMetaphone(aptr, codes);
+	code = codes[0];
+	if (!code)
+		code = "";
+
+	PG_RETURN_TEXT_P(cstring_to_text(code));
+}
+
+/*
+ * The PostgreSQL visible dmetaphone_alt function.
+ */
+
+PG_FUNCTION_INFO_V1(dmetaphone_alt);
+
+Datum
+dmetaphone_alt(PG_FUNCTION_ARGS)
+{
+	text	   *arg;
+	char	   *aptr,
+			   *codes[2],
+			   *code;
+
+#ifdef DMETAPHONE_NOSTRICT
+	if (PG_ARGISNULL(0))
+		PG_RETURN_NULL();
+#endif
+	arg = PG_GETARG_TEXT_PP(0);
+	aptr = text_to_cstring(arg);
+
+	DoubleMetaphone(aptr, codes);
+	code = codes[1];
+	if (!code)
+		code = "";
+
+	PG_RETURN_TEXT_P(cstring_to_text(code));
+}
+
+
+/* here is where we start the code imported from the perl module */
+
+/* all memory handling is done with these macros */
+
+#define META_MALLOC(v,n,t) \
+		  (v = (t*)palloc(((n)*sizeof(t))))
+
+#define META_REALLOC(v,n,t) \
+					  (v = (t*)repalloc((v),((n)*sizeof(t))))
+
+/*
+ * Don't do pfree - it seems to cause a SIGSEGV sometimes - which might have just
+ * been caused by reloading the module in development.
+ * So we rely on context cleanup - Tom Lane says pfree shouldn't be necessary
+ * in a case like this.
+ */
+
+#define META_FREE(x) ((void)true)	/* pfree((x)) */
+#else							/* not defined DMETAPHONE_MAIN */
+
+/* use the standard malloc library when not running in PostgreSQL */
+
+#define META_MALLOC(v,n,t) \
+		  (v = (t*)malloc(((n)*sizeof(t))))
+
+#define META_REALLOC(v,n,t) \
+					  (v = (t*)realloc((v),((n)*sizeof(t))))
+
+#define META_FREE(x) free((x))
+#endif							/* defined DMETAPHONE_MAIN */
+
+
+
+/* this typedef was originally in the perl module's .h file */
+
+typedef struct
+{
+	char	   *str;
+	int			length;
+	int			bufsize;
+	int			free_string_on_destroy;
+}
+
+metastring;
+
+/*
+ * remaining perl module funcs unchanged except for declaring them static
+ * and reformatting to PostgreSQL indentation and to fit in 80 cols.
+ *
+ */
+
+static metastring *
+NewMetaString(const char *init_str)
+{
+	metastring *s;
+	char		empty_string[] = "";
+
+	META_MALLOC(s, 1, metastring);
+	assert(s != NULL);
+
+	if (init_str == NULL)
+		init_str = empty_string;
+	s->length = strlen(init_str);
+	/* preallocate a bit more for potential growth */
+	s->bufsize = s->length + 7;
+
+	META_MALLOC(s->str, s->bufsize, char);
+	assert(s->str != NULL);
+
+	memcpy(s->str, init_str, s->length + 1);
+	s->free_string_on_destroy = 1;
+
+	return s;
+}
+
+
+static void
+DestroyMetaString(metastring *s)
+{
+	if (s == NULL)
+		return;
+
+	if (s->free_string_on_destroy && (s->str != NULL))
+		META_FREE(s->str);
+
+	META_FREE(s);
+}
+
+
+static void
+IncreaseBuffer(metastring *s, int chars_needed)
+{
+	META_REALLOC(s->str, (s->bufsize + chars_needed + 10), char);
+	assert(s->str != NULL);
+	s->bufsize = s->bufsize + chars_needed + 10;
+}
+
+
+static void
+MakeUpper(metastring *s)
+{
+	char	   *i;
+
+	for (i = s->str; *i; i++)
+		*i = toupper((unsigned char) *i);
+}
+
+
+static int
+IsVowel(metastring *s, int pos)
+{
+	char		c;
+
+	if ((pos < 0) || (pos >= s->length))
+		return 0;
+
+	c = *(s->str + pos);
+	if ((c == 'A') || (c == 'E') || (c == 'I') || (c == 'O') ||
+		(c == 'U') || (c == 'Y'))
+		return 1;
+
+	return 0;
+}
+
+
+static int
+SlavoGermanic(metastring *s)
+{
+	if ((char *) strstr(s->str, "W"))
+		return 1;
+	else if ((char *) strstr(s->str, "K"))
+		return 1;
+	else if ((char *) strstr(s->str, "CZ"))
+		return 1;
+	else if ((char *) strstr(s->str, "WITZ"))
+		return 1;
+	else
+		return 0;
+}
+
+
+static char
+GetAt(metastring *s, int pos)
+{
+	if ((pos < 0) || (pos >= s->length))
+		return '\0';
+
+	return ((char) *(s->str + pos));
+}
+
+
+static void
+SetAt(metastring *s, int pos, char c)
+{
+	if ((pos < 0) || (pos >= s->length))
+		return;
+
+	*(s->str + pos) = c;
+}
+
+
+/*
+   Caveats: the START value is 0 based
+*/
+static int
+StringAt(metastring *s, int start, int length,...)
+{
+	char	   *test;
+	char	   *pos;
+	va_list		ap;
+
+	if ((start < 0) || (start >= s->length))
+		return 0;
+
+	pos = (s->str + start);
+	va_start(ap, length);
+
+	do
+	{
+		test = va_arg(ap, char *);
+		if (*test && (strncmp(pos, test, length) == 0))
+		{
+			va_end(ap);
+			return 1;
+		}
+	}
+	while (strcmp(test, "") != 0);
+
+	va_end(ap);
+
+	return 0;
+}
+
+
+static void
+MetaphAdd(metastring *s, const char *new_str)
+{
+	int			add_length;
+
+	if (new_str == NULL)
+		return;
+
+	add_length = strlen(new_str);
+	if ((s->length + add_length) > (s->bufsize - 1))
+		IncreaseBuffer(s, add_length);
+
+	strcat(s->str, new_str);
+	s->length += add_length;
+}
+
+
+static void
+DoubleMetaphone(char *str, char **codes)
+{
+	int			length;
+	metastring *original;
+	metastring *primary;
+	metastring *secondary;
+	int			current;
+	int			last;
+
+	current = 0;
+	/* we need the real length and last prior to padding */
+	length = strlen(str);
+	last = length - 1;
+	original = NewMetaString(str);
+	/* Pad original so we can index beyond end */
+	MetaphAdd(original, "     ");
+
+	primary = NewMetaString("");
+	secondary = NewMetaString("");
+	primary->free_string_on_destroy = 0;
+	secondary->free_string_on_destroy = 0;
+
+	MakeUpper(original);
+
+	/* skip these when at start of word */
+	if (StringAt(original, 0, 2, "GN", "KN", "PN", "WR", "PS", ""))
+		current += 1;
+
+	/* Initial 'X' is pronounced 'Z' e.g. 'Xavier' */
+	if (GetAt(original, 0) == 'X')
+	{
+		MetaphAdd(primary, "S");	/* 'Z' maps to 'S' */
+		MetaphAdd(secondary, "S");
+		current += 1;
+	}
+
+	/* main loop */
+	while ((primary->length < 4) || (secondary->length < 4))
+	{
+		if (current >= length)
+			break;
+
+		switch (GetAt(original, current))
+		{
+			case 'A':
+			case 'E':
+			case 'I':
+			case 'O':
+			case 'U':
+			case 'Y':
+				if (current == 0)
+				{
+					/* all init vowels now map to 'A' */
+					MetaphAdd(primary, "A");
+					MetaphAdd(secondary, "A");
+				}
+				current += 1;
+				break;
+
+			case 'B':
+
+				/* "-mb", e.g", "dumb", already skipped over... */
+				MetaphAdd(primary, "P");
+				MetaphAdd(secondary, "P");
+
+				if (GetAt(original, current + 1) == 'B')
+					current += 2;
+				else
+					current += 1;
+				break;
+
+			case '\xc7':		/* C with cedilla */
+				MetaphAdd(primary, "S");
+				MetaphAdd(secondary, "S");
+				current += 1;
+				break;
+
+			case 'C':
+				/* various germanic */
+				if ((current > 1)
+					&& !IsVowel(original, current - 2)
+					&& StringAt(original, (current - 1), 3, "ACH", "")
+					&& ((GetAt(original, current + 2) != 'I')
+						&& ((GetAt(original, current + 2) != 'E')
+							|| StringAt(original, (current - 2), 6, "BACHER",
+										"MACHER", ""))))
+				{
+					MetaphAdd(primary, "K");
+					MetaphAdd(secondary, "K");
+					current += 2;
+					break;
+				}
+
+				/* special case 'caesar' */
+				if ((current == 0)
+					&& StringAt(original, current, 6, "CAESAR", ""))
+				{
+					MetaphAdd(primary, "S");
+					MetaphAdd(secondary, "S");
+					current += 2;
+					break;
+				}
+
+				/* italian 'chianti' */
+				if (StringAt(original, current, 4, "CHIA", ""))
+				{
+					MetaphAdd(primary, "K");
+					MetaphAdd(secondary, "K");
+					current += 2;
+					break;
+				}
+
+				if (StringAt(original, current, 2, "CH", ""))
+				{
+					/* find 'michael' */
+					if ((current > 0)
+						&& StringAt(original, current, 4, "CHAE", ""))
+					{
+						MetaphAdd(primary, "K");
+						MetaphAdd(secondary, "X");
+						current += 2;
+						break;
+					}
+
+					/* greek roots e.g. 'chemistry', 'chorus' */
+					if ((current == 0)
+						&& (StringAt(original, (current + 1), 5,
+									 "HARAC", "HARIS", "")
+							|| StringAt(original, (current + 1), 3, "HOR",
+										"HYM", "HIA", "HEM", ""))
+						&& !StringAt(original, 0, 5, "CHORE", ""))
+					{
+						MetaphAdd(primary, "K");
+						MetaphAdd(secondary, "K");
+						current += 2;
+						break;
+					}
+
+					/* germanic, greek, or otherwise 'ch' for 'kh' sound */
+					if ((StringAt(original, 0, 4, "VAN ", "VON ", "")
+						 || StringAt(original, 0, 3, "SCH", ""))
+					/* 'architect but not 'arch', 'orchestra', 'orchid' */
+						|| StringAt(original, (current - 2), 6, "ORCHES",
+									"ARCHIT", "ORCHID", "")
+						|| StringAt(original, (current + 2), 1, "T", "S",
+									"")
+						|| ((StringAt(original, (current - 1), 1,
+									  "A", "O", "U", "E", "")
+							 || (current == 0))
+
+					/*
+					 * e.g., 'wachtler', 'wechsler', but not 'tichner'
+					 */
+							&& StringAt(original, (current + 2), 1, "L", "R",
+										"N", "M", "B", "H", "F", "V", "W",
+										" ", "")))
+					{
+						MetaphAdd(primary, "K");
+						MetaphAdd(secondary, "K");
+					}
+					else
+					{
+						if (current > 0)
+						{
+							if (StringAt(original, 0, 2, "MC", ""))
+							{
+								/* e.g., "McHugh" */
+								MetaphAdd(primary, "K");
+								MetaphAdd(secondary, "K");
+							}
+							else
+							{
+								MetaphAdd(primary, "X");
+								MetaphAdd(secondary, "K");
+							}
+						}
+						else
+						{
+							MetaphAdd(primary, "X");
+							MetaphAdd(secondary, "X");
+						}
+					}
+					current += 2;
+					break;
+				}
+				/* e.g, 'czerny' */
+				if (StringAt(original, current, 2, "CZ", "")
+					&& !StringAt(original, (current - 2), 4, "WICZ", ""))
+				{
+					MetaphAdd(primary, "S");
+					MetaphAdd(secondary, "X");
+					current += 2;
+					break;
+				}
+
+				/* e.g., 'focaccia' */
+				if (StringAt(original, (current + 1), 3, "CIA", ""))
+				{
+					MetaphAdd(primary, "X");
+					MetaphAdd(secondary, "X");
+					current += 3;
+					break;
+				}
+
+				/* double 'C', but not if e.g. 'McClellan' */
+				if (StringAt(original, current, 2, "CC", "")
+					&& !((current == 1) && (GetAt(original, 0) == 'M')))
+				{
+					/* 'bellocchio' but not 'bacchus' */
+					if (StringAt(original, (current + 2), 1, "I", "E", "H", "")
+						&& !StringAt(original, (current + 2), 2, "HU", ""))
+					{
+						/* 'accident', 'accede' 'succeed' */
+						if (((current == 1)
+							 && (GetAt(original, current - 1) == 'A'))
+							|| StringAt(original, (current - 1), 5, "UCCEE",
+										"UCCES", ""))
+						{
+							MetaphAdd(primary, "KS");
+							MetaphAdd(secondary, "KS");
+							/* 'bacci', 'bertucci', other italian */
+						}
+						else
+						{
+							MetaphAdd(primary, "X");
+							MetaphAdd(secondary, "X");
+						}
+						current += 3;
+						break;
+					}
+					else
+					{			/* Pierce's rule */
+						MetaphAdd(primary, "K");
+						MetaphAdd(secondary, "K");
+						current += 2;
+						break;
+					}
+				}
+
+				if (StringAt(original, current, 2, "CK", "CG", "CQ", ""))
+				{
+					MetaphAdd(primary, "K");
+					MetaphAdd(secondary, "K");
+					current += 2;
+					break;
+				}
+
+				if (StringAt(original, current, 2, "CI", "CE", "CY", ""))
+				{
+					/* italian vs. english */
+					if (StringAt
+						(original, current, 3, "CIO", "CIE", "CIA", ""))
+					{
+						MetaphAdd(primary, "S");
+						MetaphAdd(secondary, "X");
+					}
+					else
+					{
+						MetaphAdd(primary, "S");
+						MetaphAdd(secondary, "S");
+					}
+					current += 2;
+					break;
+				}
+
+				/* else */
+				MetaphAdd(primary, "K");
+				MetaphAdd(secondary, "K");
+
+				/* name sent in 'mac caffrey', 'mac gregor */
+				if (StringAt(original, (current + 1), 2, " C", " Q", " G", ""))
+					current += 3;
+				else if (StringAt(original, (current + 1), 1, "C", "K", "Q", "")
+						 && !StringAt(original, (current + 1), 2,
+									  "CE", "CI", ""))
+					current += 2;
+				else
+					current += 1;
+				break;
+
+			case 'D':
+				if (StringAt(original, current, 2, "DG", ""))
+				{
+					if (StringAt(original, (current + 2), 1,
+								 "I", "E", "Y", ""))
+					{
+						/* e.g. 'edge' */
+						MetaphAdd(primary, "J");
+						MetaphAdd(secondary, "J");
+						current += 3;
+						break;
+					}
+					else
+					{
+						/* e.g. 'edgar' */
+						MetaphAdd(primary, "TK");
+						MetaphAdd(secondary, "TK");
+						current += 2;
+						break;
+					}
+				}
+
+				if (StringAt(original, current, 2, "DT", "DD", ""))
+				{
+					MetaphAdd(primary, "T");
+					MetaphAdd(secondary, "T");
+					current += 2;
+					break;
+				}
+
+				/* else */
+				MetaphAdd(primary, "T");
+				MetaphAdd(secondary, "T");
+				current += 1;
+				break;
+
+			case 'F':
+				if (GetAt(original, current + 1) == 'F')
+					current += 2;
+				else
+					current += 1;
+				MetaphAdd(primary, "F");
+				MetaphAdd(secondary, "F");
+				break;
+
+			case 'G':
+				if (GetAt(original, current + 1) == 'H')
+				{
+					if ((current > 0) && !IsVowel(original, current - 1))
+					{
+						MetaphAdd(primary, "K");
+						MetaphAdd(secondary, "K");
+						current += 2;
+						break;
+					}
+
+					if (current < 3)
+					{
+						/* 'ghislane', ghiradelli */
+						if (current == 0)
+						{
+							if (GetAt(original, current + 2) == 'I')
+							{
+								MetaphAdd(primary, "J");
+								MetaphAdd(secondary, "J");
+							}
+							else
+							{
+								MetaphAdd(primary, "K");
+								MetaphAdd(secondary, "K");
+							}
+							current += 2;
+							break;
+						}
+					}
+
+					/*
+					 * Parker's rule (with some further refinements) - e.g.,
+					 * 'hugh'
+					 */
+					if (((current > 1)
+						 && StringAt(original, (current - 2), 1,
+									 "B", "H", "D", ""))
+					/* e.g., 'bough' */
+						|| ((current > 2)
+							&& StringAt(original, (current - 3), 1,
+										"B", "H", "D", ""))
+					/* e.g., 'broughton' */
+						|| ((current > 3)
+							&& StringAt(original, (current - 4), 1,
+										"B", "H", "")))
+					{
+						current += 2;
+						break;
+					}
+					else
+					{
+						/*
+						 * e.g., 'laugh', 'McLaughlin', 'cough', 'gough',
+						 * 'rough', 'tough'
+						 */
+						if ((current > 2)
+							&& (GetAt(original, current - 1) == 'U')
+							&& StringAt(original, (current - 3), 1, "C",
+										"G", "L", "R", "T", ""))
+						{
+							MetaphAdd(primary, "F");
+							MetaphAdd(secondary, "F");
+						}
+						else if ((current > 0)
+								 && GetAt(original, current - 1) != 'I')
+						{
+
+
+							MetaphAdd(primary, "K");
+							MetaphAdd(secondary, "K");
+						}
+
+						current += 2;
+						break;
+					}
+				}
+
+				if (GetAt(original, current + 1) == 'N')
+				{
+					if ((current == 1) && IsVowel(original, 0)
+						&& !SlavoGermanic(original))
+					{
+						MetaphAdd(primary, "KN");
+						MetaphAdd(secondary, "N");
+					}
+					else
+						/* not e.g. 'cagney' */
+						if (!StringAt(original, (current + 2), 2, "EY", "")
+							&& (GetAt(original, current + 1) != 'Y')
+							&& !SlavoGermanic(original))
+					{
+						MetaphAdd(primary, "N");
+						MetaphAdd(secondary, "KN");
+					}
+					else
+					{
+						MetaphAdd(primary, "KN");
+						MetaphAdd(secondary, "KN");
+					}
+					current += 2;
+					break;
+				}
+
+				/* 'tagliaro' */
+				if (StringAt(original, (current + 1), 2, "LI", "")
+					&& !SlavoGermanic(original))
+				{
+					MetaphAdd(primary, "KL");
+					MetaphAdd(secondary, "L");
+					current += 2;
+					break;
+				}
+
+				/* -ges-,-gep-,-gel-, -gie- at beginning */
+				if ((current == 0)
+					&& ((GetAt(original, current + 1) == 'Y')
+						|| StringAt(original, (current + 1), 2, "ES", "EP",
+									"EB", "EL", "EY", "IB", "IL", "IN", "IE",
+									"EI", "ER", "")))
+				{
+					MetaphAdd(primary, "K");
+					MetaphAdd(secondary, "J");
+					current += 2;
+					break;
+				}
+
+				/* -ger-,  -gy- */
+				if ((StringAt(original, (current + 1), 2, "ER", "")
+					 || (GetAt(original, current + 1) == 'Y'))
+					&& !StringAt(original, 0, 6,
+								 "DANGER", "RANGER", "MANGER", "")
+					&& !StringAt(original, (current - 1), 1, "E", "I", "")
+					&& !StringAt(original, (current - 1), 3, "RGY", "OGY", ""))
+				{
+					MetaphAdd(primary, "K");
+					MetaphAdd(secondary, "J");
+					current += 2;
+					break;
+				}
+
+				/* italian e.g, 'biaggi' */
+				if (StringAt(original, (current + 1), 1, "E", "I", "Y", "")
+					|| StringAt(original, (current - 1), 4,
+								"AGGI", "OGGI", ""))
+				{
+					/* obvious germanic */
+					if ((StringAt(original, 0, 4, "VAN ", "VON ", "")
+						 || StringAt(original, 0, 3, "SCH", ""))
+						|| StringAt(original, (current + 1), 2, "ET", ""))
+					{
+						MetaphAdd(primary, "K");
+						MetaphAdd(secondary, "K");
+					}
+					else
+					{
+						/* always soft if french ending */
+						if (StringAt
+							(original, (current + 1), 4, "IER ", ""))
+						{
+							MetaphAdd(primary, "J");
+							MetaphAdd(secondary, "J");
+						}
+						else
+						{
+							MetaphAdd(primary, "J");
+							MetaphAdd(secondary, "K");
+						}
+					}
+					current += 2;
+					break;
+				}
+
+				if (GetAt(original, current + 1) == 'G')
+					current += 2;
+				else
+					current += 1;
+				MetaphAdd(primary, "K");
+				MetaphAdd(secondary, "K");
+				break;
+
+			case 'H':
+				/* only keep if first & before vowel or btw. 2 vowels */
+				if (((current == 0) || IsVowel(original, current - 1))
+					&& IsVowel(original, current + 1))
+				{
+					MetaphAdd(primary, "H");
+					MetaphAdd(secondary, "H");
+					current += 2;
+				}
+				else
+					/* also takes care of 'HH' */
+					current += 1;
+				break;
+
+			case 'J':
+				/* obvious spanish, 'jose', 'san jacinto' */
+				if (StringAt(original, current, 4, "JOSE", "")
+					|| StringAt(original, 0, 4, "SAN ", ""))
+				{
+					if (((current == 0)
+						 && (GetAt(original, current + 4) == ' '))
+						|| StringAt(original, 0, 4, "SAN ", ""))
+					{
+						MetaphAdd(primary, "H");
+						MetaphAdd(secondary, "H");
+					}
+					else
+					{
+						MetaphAdd(primary, "J");
+						MetaphAdd(secondary, "H");
+					}
+					current += 1;
+					break;
+				}
+
+				if ((current == 0)
+					&& !StringAt(original, current, 4, "JOSE", ""))
+				{
+					MetaphAdd(primary, "J");	/* Yankelovich/Jankelowicz */
+					MetaphAdd(secondary, "A");
+				}
+				else
+				{
+					/* spanish pron. of e.g. 'bajador' */
+					if (IsVowel(original, current - 1)
+						&& !SlavoGermanic(original)
+						&& ((GetAt(original, current + 1) == 'A')
+							|| (GetAt(original, current + 1) == 'O')))
+					{
+						MetaphAdd(primary, "J");
+						MetaphAdd(secondary, "H");
+					}
+					else
+					{
+						if (current == last)
+						{
+							MetaphAdd(primary, "J");
+							MetaphAdd(secondary, "");
+						}
+						else
+						{
+							if (!StringAt(original, (current + 1), 1, "L", "T",
+										  "K", "S", "N", "M", "B", "Z", "")
+								&& !StringAt(original, (current - 1), 1,
+											 "S", "K", "L", ""))
+							{
+								MetaphAdd(primary, "J");
+								MetaphAdd(secondary, "J");
+							}
+						}
+					}
+				}
+
+				if (GetAt(original, current + 1) == 'J')	/* it could happen! */
+					current += 2;
+				else
+					current += 1;
+				break;
+
+			case 'K':
+				if (GetAt(original, current + 1) == 'K')
+					current += 2;
+				else
+					current += 1;
+				MetaphAdd(primary, "K");
+				MetaphAdd(secondary, "K");
+				break;
+
+			case 'L':
+				if (GetAt(original, current + 1) == 'L')
+				{
+					/* spanish e.g. 'cabrillo', 'gallegos' */
+					if (((current == (length - 3))
+						 && StringAt(original, (current - 1), 4, "ILLO",
+									 "ILLA", "ALLE", ""))
+						|| ((StringAt(original, (last - 1), 2, "AS", "OS", "")
+							 || StringAt(original, last, 1, "A", "O", ""))
+							&& StringAt(original, (current - 1), 4,
+										"ALLE", "")))
+					{
+						MetaphAdd(primary, "L");
+						MetaphAdd(secondary, "");
+						current += 2;
+						break;
+					}
+					current += 2;
+				}
+				else
+					current += 1;
+				MetaphAdd(primary, "L");
+				MetaphAdd(secondary, "L");
+				break;
+
+			case 'M':
+				if ((StringAt(original, (current - 1), 3, "UMB", "")
+					 && (((current + 1) == last)
+						 || StringAt(original, (current + 2), 2, "ER", "")))
+				/* 'dumb','thumb' */
+					|| (GetAt(original, current + 1) == 'M'))
+					current += 2;
+				else
+					current += 1;
+				MetaphAdd(primary, "M");
+				MetaphAdd(secondary, "M");
+				break;
+
+			case 'N':
+				if (GetAt(original, current + 1) == 'N')
+					current += 2;
+				else
+					current += 1;
+				MetaphAdd(primary, "N");
+				MetaphAdd(secondary, "N");
+				break;
+
+			case '\xd1':		/* N with tilde */
+				current += 1;
+				MetaphAdd(primary, "N");
+				MetaphAdd(secondary, "N");
+				break;
+
+			case 'P':
+				if (GetAt(original, current + 1) == 'H')
+				{
+					MetaphAdd(primary, "F");
+					MetaphAdd(secondary, "F");
+					current += 2;
+					break;
+				}
+
+				/* also account for "campbell", "raspberry" */
+				if (StringAt(original, (current + 1), 1, "P", "B", ""))
+					current += 2;
+				else
+					current += 1;
+				MetaphAdd(primary, "P");
+				MetaphAdd(secondary, "P");
+				break;
+
+			case 'Q':
+				if (GetAt(original, current + 1) == 'Q')
+					current += 2;
+				else
+					current += 1;
+				MetaphAdd(primary, "K");
+				MetaphAdd(secondary, "K");
+				break;
+
+			case 'R':
+				/* french e.g. 'rogier', but exclude 'hochmeier' */
+				if ((current == last)
+					&& !SlavoGermanic(original)
+					&& StringAt(original, (current - 2), 2, "IE", "")
+					&& !StringAt(original, (current - 4), 2, "ME", "MA", ""))
+				{
+					MetaphAdd(primary, "");
+					MetaphAdd(secondary, "R");
+				}
+				else
+				{
+					MetaphAdd(primary, "R");
+					MetaphAdd(secondary, "R");
+				}
+
+				if (GetAt(original, current + 1) == 'R')
+					current += 2;
+				else
+					current += 1;
+				break;
+
+			case 'S':
+				/* special cases 'island', 'isle', 'carlisle', 'carlysle' */
+				if (StringAt(original, (current - 1), 3, "ISL", "YSL", ""))
+				{
+					current += 1;
+					break;
+				}
+
+				/* special case 'sugar-' */
+				if ((current == 0)
+					&& StringAt(original, current, 5, "SUGAR", ""))
+				{
+					MetaphAdd(primary, "X");
+					MetaphAdd(secondary, "S");
+					current += 1;
+					break;
+				}
+
+				if (StringAt(original, current, 2, "SH", ""))
+				{
+					/* germanic */
+					if (StringAt
+						(original, (current + 1), 4, "HEIM", "HOEK", "HOLM",
+						 "HOLZ", ""))
+					{
+						MetaphAdd(primary, "S");
+						MetaphAdd(secondary, "S");
+					}
+					else
+					{
+						MetaphAdd(primary, "X");
+						MetaphAdd(secondary, "X");
+					}
+					current += 2;
+					break;
+				}
+
+				/* italian & armenian */
+				if (StringAt(original, current, 3, "SIO", "SIA", "")
+					|| StringAt(original, current, 4, "SIAN", ""))
+				{
+					if (!SlavoGermanic(original))
+					{
+						MetaphAdd(primary, "S");
+						MetaphAdd(secondary, "X");
+					}
+					else
+					{
+						MetaphAdd(primary, "S");
+						MetaphAdd(secondary, "S");
+					}
+					current += 3;
+					break;
+				}
+
+				/*
+				 * german & anglicisations, e.g. 'smith' match 'schmidt',
+				 * 'snider' match 'schneider' also, -sz- in slavic language
+				 * although in hungarian it is pronounced 's'
+				 */
+				if (((current == 0)
+					 && StringAt(original, (current + 1), 1,
+								 "M", "N", "L", "W", ""))
+					|| StringAt(original, (current + 1), 1, "Z", ""))
+				{
+					MetaphAdd(primary, "S");
+					MetaphAdd(secondary, "X");
+					if (StringAt(original, (current + 1), 1, "Z", ""))
+						current += 2;
+					else
+						current += 1;
+					break;
+				}
+
+				if (StringAt(original, current, 2, "SC", ""))
+				{
+					/* Schlesinger's rule */
+					if (GetAt(original, current + 2) == 'H')
+					{
+						/* dutch origin, e.g. 'school', 'schooner' */
+						if (StringAt(original, (current + 3), 2,
+									 "OO", "ER", "EN",
+									 "UY", "ED", "EM", ""))
+						{
+							/* 'schermerhorn', 'schenker' */
+							if (StringAt(original, (current + 3), 2,
+										 "ER", "EN", ""))
+							{
+								MetaphAdd(primary, "X");
+								MetaphAdd(secondary, "SK");
+							}
+							else
+							{
+								MetaphAdd(primary, "SK");
+								MetaphAdd(secondary, "SK");
+							}
+							current += 3;
+							break;
+						}
+						else
+						{
+							if ((current == 0) && !IsVowel(original, 3)
+								&& (GetAt(original, 3) != 'W'))
+							{
+								MetaphAdd(primary, "X");
+								MetaphAdd(secondary, "S");
+							}
+							else
+							{
+								MetaphAdd(primary, "X");
+								MetaphAdd(secondary, "X");
+							}
+							current += 3;
+							break;
+						}
+					}
+
+					if (StringAt(original, (current + 2), 1,
+								 "I", "E", "Y", ""))
+					{
+						MetaphAdd(primary, "S");
+						MetaphAdd(secondary, "S");
+						current += 3;
+						break;
+					}
+					/* else */
+					MetaphAdd(primary, "SK");
+					MetaphAdd(secondary, "SK");
+					current += 3;
+					break;
+				}
+
+				/* french e.g. 'resnais', 'artois' */
+				if ((current == last)
+					&& StringAt(original, (current - 2), 2, "AI", "OI", ""))
+				{
+					MetaphAdd(primary, "");
+					MetaphAdd(secondary, "S");
+				}
+				else
+				{
+					MetaphAdd(primary, "S");
+					MetaphAdd(secondary, "S");
+				}
+
+				if (StringAt(original, (current + 1), 1, "S", "Z", ""))
+					current += 2;
+				else
+					current += 1;
+				break;
+
+			case 'T':
+				if (StringAt(original, current, 4, "TION", ""))
+				{
+					MetaphAdd(primary, "X");
+					MetaphAdd(secondary, "X");
+					current += 3;
+					break;
+				}
+
+				if (StringAt(original, current, 3, "TIA", "TCH", ""))
+				{
+					MetaphAdd(primary, "X");
+					MetaphAdd(secondary, "X");
+					current += 3;
+					break;
+				}
+
+				if (StringAt(original, current, 2, "TH", "")
+					|| StringAt(original, current, 3, "TTH", ""))
+				{
+					/* special case 'thomas', 'thames' or germanic */
+					if (StringAt(original, (current + 2), 2, "OM", "AM", "")
+						|| StringAt(original, 0, 4, "VAN ", "VON ", "")
+						|| StringAt(original, 0, 3, "SCH", ""))
+					{
+						MetaphAdd(primary, "T");
+						MetaphAdd(secondary, "T");
+					}
+					else
+					{
+						MetaphAdd(primary, "0");
+						MetaphAdd(secondary, "T");
+					}
+					current += 2;
+					break;
+				}
+
+				if (StringAt(original, (current + 1), 1, "T", "D", ""))
+					current += 2;
+				else
+					current += 1;
+				MetaphAdd(primary, "T");
+				MetaphAdd(secondary, "T");
+				break;
+
+			case 'V':
+				if (GetAt(original, current + 1) == 'V')
+					current += 2;
+				else
+					current += 1;
+				MetaphAdd(primary, "F");
+				MetaphAdd(secondary, "F");
+				break;
+
+			case 'W':
+				/* can also be in middle of word */
+				if (StringAt(original, current, 2, "WR", ""))
+				{
+					MetaphAdd(primary, "R");
+					MetaphAdd(secondary, "R");
+					current += 2;
+					break;
+				}
+
+				if ((current == 0)
+					&& (IsVowel(original, current + 1)
+						|| StringAt(original, current, 2, "WH", "")))
+				{
+					/* Wasserman should match Vasserman */
+					if (IsVowel(original, current + 1))
+					{
+						MetaphAdd(primary, "A");
+						MetaphAdd(secondary, "F");
+					}
+					else
+					{
+						/* need Uomo to match Womo */
+						MetaphAdd(primary, "A");
+						MetaphAdd(secondary, "A");
+					}
+				}
+
+				/* Arnow should match Arnoff */
+				if (((current == last) && IsVowel(original, current - 1))
+					|| StringAt(original, (current - 1), 5, "EWSKI", "EWSKY",
+								"OWSKI", "OWSKY", "")
+					|| StringAt(original, 0, 3, "SCH", ""))
+				{
+					MetaphAdd(primary, "");
+					MetaphAdd(secondary, "F");
+					current += 1;
+					break;
+				}
+
+				/* polish e.g. 'filipowicz' */
+				if (StringAt(original, current, 4, "WICZ", "WITZ", ""))
+				{
+					MetaphAdd(primary, "TS");
+					MetaphAdd(secondary, "FX");
+					current += 4;
+					break;
+				}
+
+				/* else skip it */
+				current += 1;
+				break;
+
+			case 'X':
+				/* french e.g. breaux */
+				if (!((current == last)
+					  && (StringAt(original, (current - 3), 3,
+								   "IAU", "EAU", "")
+						  || StringAt(original, (current - 2), 2,
+									  "AU", "OU", ""))))
+				{
+					MetaphAdd(primary, "KS");
+					MetaphAdd(secondary, "KS");
+				}
+
+
+				if (StringAt(original, (current + 1), 1, "C", "X", ""))
+					current += 2;
+				else
+					current += 1;
+				break;
+
+			case 'Z':
+				/* chinese pinyin e.g. 'zhao' */
+				if (GetAt(original, current + 1) == 'H')
+				{
+					MetaphAdd(primary, "J");
+					MetaphAdd(secondary, "J");
+					current += 2;
+					break;
+				}
+				else if (StringAt(original, (current + 1), 2,
+								  "ZO", "ZI", "ZA", "")
+						 || (SlavoGermanic(original)
+							 && ((current > 0)
+								 && GetAt(original, current - 1) != 'T')))
+				{
+					MetaphAdd(primary, "S");
+					MetaphAdd(secondary, "TS");
+				}
+				else
+				{
+					MetaphAdd(primary, "S");
+					MetaphAdd(secondary, "S");
+				}
+
+				if (GetAt(original, current + 1) == 'Z')
+					current += 2;
+				else
+					current += 1;
+				break;
+
+			default:
+				current += 1;
+		}
+
+		/*
+		 * printf("PRIMARY: %s\n", primary->str); printf("SECONDARY: %s\n",
+		 * secondary->str);
+		 */
+	}
+
+
+	if (primary->length > 4)
+		SetAt(primary, 4, '\0');
+
+	if (secondary->length > 4)
+		SetAt(secondary, 4, '\0');
+
+	*codes = primary->str;
+	*++codes = secondary->str;
+
+	DestroyMetaString(original);
+	DestroyMetaString(primary);
+	DestroyMetaString(secondary);
+}
+
+#ifdef DMETAPHONE_MAIN
+
+/* just for testing - not part of the perl code */
+
+main(int argc, char **argv)
+{
+	char	   *codes[2];
+
+	if (argc > 1)
+	{
+		DoubleMetaphone(argv[1], codes);
+		printf("%s|%s\n", codes[0], codes[1]);
+	}
+}
+
+#endif
diff --git a/contrib/fuzzystrmatch/expected/fuzzystrmatch.out b/contrib/fuzzystrmatch/expected/fuzzystrmatch.out
new file mode 100644
index 0000000..493c95c
--- /dev/null
+++ b/contrib/fuzzystrmatch/expected/fuzzystrmatch.out
@@ -0,0 +1,67 @@
+CREATE EXTENSION fuzzystrmatch;
+SELECT soundex('hello world!');
+ soundex 
+---------
+ H464
+(1 row)
+
+SELECT soundex('Anne'), soundex('Ann'), difference('Anne', 'Ann');
+ soundex | soundex | difference 
+---------+---------+------------
+ A500    | A500    |          4
+(1 row)
+
+SELECT soundex('Anne'), soundex('Andrew'), difference('Anne', 'Andrew');
+ soundex | soundex | difference 
+---------+---------+------------
+ A500    | A536    |          2
+(1 row)
+
+SELECT soundex('Anne'), soundex('Margaret'), difference('Anne', 'Margaret');
+ soundex | soundex | difference 
+---------+---------+------------
+ A500    | M626    |          0
+(1 row)
+
+SELECT levenshtein('GUMBO', 'GAMBOL');
+ levenshtein 
+-------------
+           2
+(1 row)
+
+SELECT levenshtein('GUMBO', 'GAMBOL', 2, 1, 1);
+ levenshtein 
+-------------
+           3
+(1 row)
+
+SELECT levenshtein_less_equal('extensive', 'exhaustive', 2);
+ levenshtein_less_equal 
+------------------------
+                      3
+(1 row)
+
+SELECT levenshtein_less_equal('extensive', 'exhaustive', 4);
+ levenshtein_less_equal 
+------------------------
+                      4
+(1 row)
+
+SELECT metaphone('GUMBO', 4);
+ metaphone 
+-----------
+ KM
+(1 row)
+
+SELECT dmetaphone('gumbo');
+ dmetaphone 
+------------
+ KMP
+(1 row)
+
+SELECT dmetaphone_alt('gumbo');
+ dmetaphone_alt 
+----------------
+ KMP
+(1 row)
+
diff --git a/contrib/fuzzystrmatch/fuzzystrmatch--1.0--1.1.sql b/contrib/fuzzystrmatch/fuzzystrmatch--1.0--1.1.sql
new file mode 100644
index 0000000..f2b1555
--- /dev/null
+++ b/contrib/fuzzystrmatch/fuzzystrmatch--1.0--1.1.sql
@@ -0,0 +1,15 @@
+/* contrib/fuzzystrmatch/fuzzystrmatch--1.0--1.1.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION fuzzystrmatch UPDATE TO '1.1'" to load this file. \quit
+
+ALTER FUNCTION levenshtein(text, text) PARALLEL SAFE;
+ALTER FUNCTION levenshtein(text, text, int, int, int) PARALLEL SAFE;
+ALTER FUNCTION levenshtein_less_equal(text, text, int) PARALLEL SAFE;
+ALTER FUNCTION levenshtein_less_equal(text, text, int, int, int, int) PARALLEL SAFE;
+ALTER FUNCTION metaphone(text, int) PARALLEL SAFE;
+ALTER FUNCTION soundex(text) PARALLEL SAFE;
+ALTER FUNCTION text_soundex(text) PARALLEL SAFE;
+ALTER FUNCTION difference(text, text) PARALLEL SAFE;
+ALTER FUNCTION dmetaphone(text) PARALLEL SAFE;
+ALTER FUNCTION dmetaphone_alt(text) PARALLEL SAFE;
diff --git a/contrib/fuzzystrmatch/fuzzystrmatch--1.1.sql b/contrib/fuzzystrmatch/fuzzystrmatch--1.1.sql
new file mode 100644
index 0000000..41de9d9
--- /dev/null
+++ b/contrib/fuzzystrmatch/fuzzystrmatch--1.1.sql
@@ -0,0 +1,44 @@
+/* contrib/fuzzystrmatch/fuzzystrmatch--1.1.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION fuzzystrmatch" to load this file. \quit
+
+CREATE FUNCTION levenshtein (text,text) RETURNS int
+AS 'MODULE_PATHNAME','levenshtein'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION levenshtein (text,text,int,int,int) RETURNS int
+AS 'MODULE_PATHNAME','levenshtein_with_costs'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION levenshtein_less_equal (text,text,int) RETURNS int
+AS 'MODULE_PATHNAME','levenshtein_less_equal'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION levenshtein_less_equal (text,text,int,int,int,int) RETURNS int
+AS 'MODULE_PATHNAME','levenshtein_less_equal_with_costs'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION metaphone (text,int) RETURNS text
+AS 'MODULE_PATHNAME','metaphone'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION soundex(text) RETURNS text
+AS 'MODULE_PATHNAME', 'soundex'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION text_soundex(text) RETURNS text
+AS 'MODULE_PATHNAME', 'soundex'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION difference(text,text) RETURNS int
+AS 'MODULE_PATHNAME', 'difference'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION dmetaphone (text) RETURNS text
+AS 'MODULE_PATHNAME', 'dmetaphone'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION dmetaphone_alt (text) RETURNS text
+AS 'MODULE_PATHNAME', 'dmetaphone_alt'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
diff --git a/contrib/fuzzystrmatch/fuzzystrmatch.c b/contrib/fuzzystrmatch/fuzzystrmatch.c
new file mode 100644
index 0000000..ccbb84b
--- /dev/null
+++ b/contrib/fuzzystrmatch/fuzzystrmatch.c
@@ -0,0 +1,792 @@
+/*
+ * fuzzystrmatch.c
+ *
+ * Functions for "fuzzy" comparison of strings
+ *
+ * Joe Conway <mail@joeconway.com>
+ *
+ * contrib/fuzzystrmatch/fuzzystrmatch.c
+ * Copyright (c) 2001-2020, PostgreSQL Global Development Group
+ * ALL RIGHTS RESERVED;
+ *
+ * metaphone()
+ * -----------
+ * Modified for PostgreSQL by Joe Conway.
+ * Based on CPAN's "Text-Metaphone-1.96" by Michael G Schwern <schwern@pobox.com>
+ * Code slightly modified for use as PostgreSQL function (palloc, elog, etc).
+ * Metaphone was originally created by Lawrence Philips and presented in article
+ * in "Computer Language" December 1990 issue.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation for any purpose, without fee, and without a written agreement
+ * is hereby granted, provided that the above copyright notice and this
+ * paragraph and the following two paragraphs appear in all copies.
+ *
+ * IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
+ * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
+ * DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ */
+
+#include "postgres.h"
+
+#include <ctype.h>
+
+#include "mb/pg_wchar.h"
+#include "utils/builtins.h"
+#include "utils/varlena.h"
+
+PG_MODULE_MAGIC;
+
+/*
+ * Soundex
+ */
+static void _soundex(const char *instr, char *outstr);
+
+#define SOUNDEX_LEN 4
+
+/*									ABCDEFGHIJKLMNOPQRSTUVWXYZ */
+static const char *soundex_table = "01230120022455012623010202";
+
+static char
+soundex_code(char letter)
+{
+	letter = toupper((unsigned char) letter);
+	/* Defend against non-ASCII letters */
+	if (letter >= 'A' && letter <= 'Z')
+		return soundex_table[letter - 'A'];
+	return letter;
+}
+
+/*
+ * Metaphone
+ */
+#define MAX_METAPHONE_STRLEN		255
+
+/*
+ * Original code by Michael G Schwern starts here.
+ * Code slightly modified for use as PostgreSQL function.
+ */
+
+
+/**************************************************************************
+	metaphone -- Breaks english phrases down into their phonemes.
+
+	Input
+		word			--	An english word to be phonized
+		max_phonemes	--	How many phonemes to calculate.  If 0, then it
+							will phonize the entire phrase.
+		phoned_word		--	The final phonized word.  (We'll allocate the
+							memory.)
+	Output
+		error	--	A simple error flag, returns true or false
+
+	NOTES:	ALL non-alpha characters are ignored, this includes whitespace,
+	although non-alpha characters will break up phonemes.
+****************************************************************************/
+
+
+/*	I add modifications to the traditional metaphone algorithm that you
+	might find in books.  Define this if you want metaphone to behave
+	traditionally */
+#undef USE_TRADITIONAL_METAPHONE
+
+/* Special encodings */
+#define  SH		'X'
+#define  TH		'0'
+
+static char Lookahead(char *word, int how_far);
+static void _metaphone(char *word, int max_phonemes, char **phoned_word);
+
+/* Metachar.h ... little bits about characters for metaphone */
+
+
+/*-- Character encoding array & accessing macros --*/
+/* Stolen directly out of the book... */
+static const char _codes[26] = {
+	1, 16, 4, 16, 9, 2, 4, 16, 9, 2, 0, 2, 2, 2, 1, 4, 0, 2, 4, 4, 1, 0, 0, 0, 8, 0
+/*	a  b c	d e f g  h i j k l m n o p q r s t u v w x y z */
+};
+
+static int
+getcode(char c)
+{
+	if (isalpha((unsigned char) c))
+	{
+		c = toupper((unsigned char) c);
+		/* Defend against non-ASCII letters */
+		if (c >= 'A' && c <= 'Z')
+			return _codes[c - 'A'];
+	}
+	return 0;
+}
+
+#define isvowel(c)	(getcode(c) & 1)	/* AEIOU */
+
+/* These letters are passed through unchanged */
+#define NOCHANGE(c) (getcode(c) & 2)	/* FJMNR */
+
+/* These form diphthongs when preceding H */
+#define AFFECTH(c)	(getcode(c) & 4)	/* CGPST */
+
+/* These make C and G soft */
+#define MAKESOFT(c) (getcode(c) & 8)	/* EIY */
+
+/* These prevent GH from becoming F */
+#define NOGHTOF(c)	(getcode(c) & 16)	/* BDH */
+
+PG_FUNCTION_INFO_V1(levenshtein_with_costs);
+Datum
+levenshtein_with_costs(PG_FUNCTION_ARGS)
+{
+	text	   *src = PG_GETARG_TEXT_PP(0);
+	text	   *dst = PG_GETARG_TEXT_PP(1);
+	int			ins_c = PG_GETARG_INT32(2);
+	int			del_c = PG_GETARG_INT32(3);
+	int			sub_c = PG_GETARG_INT32(4);
+	const char *s_data;
+	const char *t_data;
+	int			s_bytes,
+				t_bytes;
+
+	/* Extract a pointer to the actual character data */
+	s_data = VARDATA_ANY(src);
+	t_data = VARDATA_ANY(dst);
+	/* Determine length of each string in bytes */
+	s_bytes = VARSIZE_ANY_EXHDR(src);
+	t_bytes = VARSIZE_ANY_EXHDR(dst);
+
+	PG_RETURN_INT32(varstr_levenshtein(s_data, s_bytes, t_data, t_bytes,
+									   ins_c, del_c, sub_c, false));
+}
+
+
+PG_FUNCTION_INFO_V1(levenshtein);
+Datum
+levenshtein(PG_FUNCTION_ARGS)
+{
+	text	   *src = PG_GETARG_TEXT_PP(0);
+	text	   *dst = PG_GETARG_TEXT_PP(1);
+	const char *s_data;
+	const char *t_data;
+	int			s_bytes,
+				t_bytes;
+
+	/* Extract a pointer to the actual character data */
+	s_data = VARDATA_ANY(src);
+	t_data = VARDATA_ANY(dst);
+	/* Determine length of each string in bytes */
+	s_bytes = VARSIZE_ANY_EXHDR(src);
+	t_bytes = VARSIZE_ANY_EXHDR(dst);
+
+	PG_RETURN_INT32(varstr_levenshtein(s_data, s_bytes, t_data, t_bytes,
+									   1, 1, 1, false));
+}
+
+
+PG_FUNCTION_INFO_V1(levenshtein_less_equal_with_costs);
+Datum
+levenshtein_less_equal_with_costs(PG_FUNCTION_ARGS)
+{
+	text	   *src = PG_GETARG_TEXT_PP(0);
+	text	   *dst = PG_GETARG_TEXT_PP(1);
+	int			ins_c = PG_GETARG_INT32(2);
+	int			del_c = PG_GETARG_INT32(3);
+	int			sub_c = PG_GETARG_INT32(4);
+	int			max_d = PG_GETARG_INT32(5);
+	const char *s_data;
+	const char *t_data;
+	int			s_bytes,
+				t_bytes;
+
+	/* Extract a pointer to the actual character data */
+	s_data = VARDATA_ANY(src);
+	t_data = VARDATA_ANY(dst);
+	/* Determine length of each string in bytes */
+	s_bytes = VARSIZE_ANY_EXHDR(src);
+	t_bytes = VARSIZE_ANY_EXHDR(dst);
+
+	PG_RETURN_INT32(varstr_levenshtein_less_equal(s_data, s_bytes,
+												  t_data, t_bytes,
+												  ins_c, del_c, sub_c,
+												  max_d, false));
+}
+
+
+PG_FUNCTION_INFO_V1(levenshtein_less_equal);
+Datum
+levenshtein_less_equal(PG_FUNCTION_ARGS)
+{
+	text	   *src = PG_GETARG_TEXT_PP(0);
+	text	   *dst = PG_GETARG_TEXT_PP(1);
+	int			max_d = PG_GETARG_INT32(2);
+	const char *s_data;
+	const char *t_data;
+	int			s_bytes,
+				t_bytes;
+
+	/* Extract a pointer to the actual character data */
+	s_data = VARDATA_ANY(src);
+	t_data = VARDATA_ANY(dst);
+	/* Determine length of each string in bytes */
+	s_bytes = VARSIZE_ANY_EXHDR(src);
+	t_bytes = VARSIZE_ANY_EXHDR(dst);
+
+	PG_RETURN_INT32(varstr_levenshtein_less_equal(s_data, s_bytes,
+												  t_data, t_bytes,
+												  1, 1, 1,
+												  max_d, false));
+}
+
+
+/*
+ * Calculates the metaphone of an input string.
+ * Returns number of characters requested
+ * (suggested value is 4)
+ */
+PG_FUNCTION_INFO_V1(metaphone);
+Datum
+metaphone(PG_FUNCTION_ARGS)
+{
+	char	   *str_i = TextDatumGetCString(PG_GETARG_DATUM(0));
+	size_t		str_i_len = strlen(str_i);
+	int			reqlen;
+	char	   *metaph;
+
+	/* return an empty string if we receive one */
+	if (!(str_i_len > 0))
+		PG_RETURN_TEXT_P(cstring_to_text(""));
+
+	if (str_i_len > MAX_METAPHONE_STRLEN)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("argument exceeds the maximum length of %d bytes",
+						MAX_METAPHONE_STRLEN)));
+
+	reqlen = PG_GETARG_INT32(1);
+	if (reqlen > MAX_METAPHONE_STRLEN)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("output exceeds the maximum length of %d bytes",
+						MAX_METAPHONE_STRLEN)));
+
+	if (!(reqlen > 0))
+		ereport(ERROR,
+				(errcode(ERRCODE_ZERO_LENGTH_CHARACTER_STRING),
+				 errmsg("output cannot be empty string")));
+
+	_metaphone(str_i, reqlen, &metaph);
+	PG_RETURN_TEXT_P(cstring_to_text(metaph));
+}
+
+
+/*
+ * Original code by Michael G Schwern starts here.
+ * Code slightly modified for use as PostgreSQL
+ * function (palloc, etc).
+ */
+
+/* I suppose I could have been using a character pointer instead of
+ * accessing the array directly... */
+
+/* Look at the next letter in the word */
+#define Next_Letter (toupper((unsigned char) word[w_idx+1]))
+/* Look at the current letter in the word */
+#define Curr_Letter (toupper((unsigned char) word[w_idx]))
+/* Go N letters back. */
+#define Look_Back_Letter(n) \
+	(w_idx >= (n) ? toupper((unsigned char) word[w_idx-(n)]) : '\0')
+/* Previous letter.  I dunno, should this return null on failure? */
+#define Prev_Letter (Look_Back_Letter(1))
+/* Look two letters down.  It makes sure you don't walk off the string. */
+#define After_Next_Letter \
+	(Next_Letter != '\0' ? toupper((unsigned char) word[w_idx+2]) : '\0')
+#define Look_Ahead_Letter(n) toupper((unsigned char) Lookahead(word+w_idx, n))
+
+
+/* Allows us to safely look ahead an arbitrary # of letters */
+/* I probably could have just used strlen... */
+static char
+Lookahead(char *word, int how_far)
+{
+	char		letter_ahead = '\0';	/* null by default */
+	int			idx;
+
+	for (idx = 0; word[idx] != '\0' && idx < how_far; idx++);
+	/* Edge forward in the string... */
+
+	letter_ahead = word[idx];	/* idx will be either == to how_far or at the
+								 * end of the string */
+	return letter_ahead;
+}
+
+
+/* phonize one letter */
+#define Phonize(c)	do {(*phoned_word)[p_idx++] = c;} while (0)
+/* Slap a null character on the end of the phoned word */
+#define End_Phoned_Word do {(*phoned_word)[p_idx] = '\0';} while (0)
+/* How long is the phoned word? */
+#define Phone_Len	(p_idx)
+
+/* Note is a letter is a 'break' in the word */
+#define Isbreak(c)	(!isalpha((unsigned char) (c)))
+
+
+static void
+_metaphone(char *word,			/* IN */
+		   int max_phonemes,
+		   char **phoned_word)	/* OUT */
+{
+	int			w_idx = 0;		/* point in the phonization we're at. */
+	int			p_idx = 0;		/* end of the phoned phrase */
+
+	/*-- Parameter checks --*/
+
+	/*
+	 * Shouldn't be necessary, but left these here anyway jec Aug 3, 2001
+	 */
+
+	/* Negative phoneme length is meaningless */
+	if (!(max_phonemes > 0))
+		/* internal error */
+		elog(ERROR, "metaphone: Requested output length must be > 0");
+
+	/* Empty/null string is meaningless */
+	if ((word == NULL) || !(strlen(word) > 0))
+		/* internal error */
+		elog(ERROR, "metaphone: Input string length must be > 0");
+
+	/*-- Allocate memory for our phoned_phrase --*/
+	if (max_phonemes == 0)
+	{							/* Assume largest possible */
+		*phoned_word = palloc(sizeof(char) * strlen(word) + 1);
+	}
+	else
+	{
+		*phoned_word = palloc(sizeof(char) * max_phonemes + 1);
+	}
+
+	/*-- The first phoneme has to be processed specially. --*/
+	/* Find our first letter */
+	for (; !isalpha((unsigned char) (Curr_Letter)); w_idx++)
+	{
+		/* On the off chance we were given nothing but crap... */
+		if (Curr_Letter == '\0')
+		{
+			End_Phoned_Word;
+			return;
+		}
+	}
+
+	switch (Curr_Letter)
+	{
+			/* AE becomes E */
+		case 'A':
+			if (Next_Letter == 'E')
+			{
+				Phonize('E');
+				w_idx += 2;
+			}
+			/* Remember, preserve vowels at the beginning */
+			else
+			{
+				Phonize('A');
+				w_idx++;
+			}
+			break;
+			/* [GKP]N becomes N */
+		case 'G':
+		case 'K':
+		case 'P':
+			if (Next_Letter == 'N')
+			{
+				Phonize('N');
+				w_idx += 2;
+			}
+			break;
+
+			/*
+			 * WH becomes H, WR becomes R W if followed by a vowel
+			 */
+		case 'W':
+			if (Next_Letter == 'H' ||
+				Next_Letter == 'R')
+			{
+				Phonize(Next_Letter);
+				w_idx += 2;
+			}
+			else if (isvowel(Next_Letter))
+			{
+				Phonize('W');
+				w_idx += 2;
+			}
+			/* else ignore */
+			break;
+			/* X becomes S */
+		case 'X':
+			Phonize('S');
+			w_idx++;
+			break;
+			/* Vowels are kept */
+
+			/*
+			 * We did A already case 'A': case 'a':
+			 */
+		case 'E':
+		case 'I':
+		case 'O':
+		case 'U':
+			Phonize(Curr_Letter);
+			w_idx++;
+			break;
+		default:
+			/* do nothing */
+			break;
+	}
+
+
+
+	/* On to the metaphoning */
+	for (; Curr_Letter != '\0' &&
+		 (max_phonemes == 0 || Phone_Len < max_phonemes);
+		 w_idx++)
+	{
+		/*
+		 * How many letters to skip because an earlier encoding handled
+		 * multiple letters
+		 */
+		unsigned short int skip_letter = 0;
+
+
+		/*
+		 * THOUGHT:  It would be nice if, rather than having things like...
+		 * well, SCI.  For SCI you encode the S, then have to remember to skip
+		 * the C.  So the phonome SCI invades both S and C.  It would be
+		 * better, IMHO, to skip the C from the S part of the encoding. Hell,
+		 * I'm trying it.
+		 */
+
+		/* Ignore non-alphas */
+		if (!isalpha((unsigned char) (Curr_Letter)))
+			continue;
+
+		/* Drop duplicates, except CC */
+		if (Curr_Letter == Prev_Letter &&
+			Curr_Letter != 'C')
+			continue;
+
+		switch (Curr_Letter)
+		{
+				/* B -> B unless in MB */
+			case 'B':
+				if (Prev_Letter != 'M')
+					Phonize('B');
+				break;
+
+				/*
+				 * 'sh' if -CIA- or -CH, but not SCH, except SCHW. (SCHW is
+				 * handled in S) S if -CI-, -CE- or -CY- dropped if -SCI-,
+				 * SCE-, -SCY- (handed in S) else K
+				 */
+			case 'C':
+				if (MAKESOFT(Next_Letter))
+				{				/* C[IEY] */
+					if (After_Next_Letter == 'A' &&
+						Next_Letter == 'I')
+					{			/* CIA */
+						Phonize(SH);
+					}
+					/* SC[IEY] */
+					else if (Prev_Letter == 'S')
+					{
+						/* Dropped */
+					}
+					else
+						Phonize('S');
+				}
+				else if (Next_Letter == 'H')
+				{
+#ifndef USE_TRADITIONAL_METAPHONE
+					if (After_Next_Letter == 'R' ||
+						Prev_Letter == 'S')
+					{			/* Christ, School */
+						Phonize('K');
+					}
+					else
+						Phonize(SH);
+#else
+					Phonize(SH);
+#endif
+					skip_letter++;
+				}
+				else
+					Phonize('K');
+				break;
+
+				/*
+				 * J if in -DGE-, -DGI- or -DGY- else T
+				 */
+			case 'D':
+				if (Next_Letter == 'G' &&
+					MAKESOFT(After_Next_Letter))
+				{
+					Phonize('J');
+					skip_letter++;
+				}
+				else
+					Phonize('T');
+				break;
+
+				/*
+				 * F if in -GH and not B--GH, D--GH, -H--GH, -H---GH else
+				 * dropped if -GNED, -GN, else dropped if -DGE-, -DGI- or
+				 * -DGY- (handled in D) else J if in -GE-, -GI, -GY and not GG
+				 * else K
+				 */
+			case 'G':
+				if (Next_Letter == 'H')
+				{
+					if (!(NOGHTOF(Look_Back_Letter(3)) ||
+						  Look_Back_Letter(4) == 'H'))
+					{
+						Phonize('F');
+						skip_letter++;
+					}
+					else
+					{
+						/* silent */
+					}
+				}
+				else if (Next_Letter == 'N')
+				{
+					if (Isbreak(After_Next_Letter) ||
+						(After_Next_Letter == 'E' &&
+						 Look_Ahead_Letter(3) == 'D'))
+					{
+						/* dropped */
+					}
+					else
+						Phonize('K');
+				}
+				else if (MAKESOFT(Next_Letter) &&
+						 Prev_Letter != 'G')
+					Phonize('J');
+				else
+					Phonize('K');
+				break;
+				/* H if before a vowel and not after C,G,P,S,T */
+			case 'H':
+				if (isvowel(Next_Letter) &&
+					!AFFECTH(Prev_Letter))
+					Phonize('H');
+				break;
+
+				/*
+				 * dropped if after C else K
+				 */
+			case 'K':
+				if (Prev_Letter != 'C')
+					Phonize('K');
+				break;
+
+				/*
+				 * F if before H else P
+				 */
+			case 'P':
+				if (Next_Letter == 'H')
+					Phonize('F');
+				else
+					Phonize('P');
+				break;
+
+				/*
+				 * K
+				 */
+			case 'Q':
+				Phonize('K');
+				break;
+
+				/*
+				 * 'sh' in -SH-, -SIO- or -SIA- or -SCHW- else S
+				 */
+			case 'S':
+				if (Next_Letter == 'I' &&
+					(After_Next_Letter == 'O' ||
+					 After_Next_Letter == 'A'))
+					Phonize(SH);
+				else if (Next_Letter == 'H')
+				{
+					Phonize(SH);
+					skip_letter++;
+				}
+#ifndef USE_TRADITIONAL_METAPHONE
+				else if (Next_Letter == 'C' &&
+						 Look_Ahead_Letter(2) == 'H' &&
+						 Look_Ahead_Letter(3) == 'W')
+				{
+					Phonize(SH);
+					skip_letter += 2;
+				}
+#endif
+				else
+					Phonize('S');
+				break;
+
+				/*
+				 * 'sh' in -TIA- or -TIO- else 'th' before H else T
+				 */
+			case 'T':
+				if (Next_Letter == 'I' &&
+					(After_Next_Letter == 'O' ||
+					 After_Next_Letter == 'A'))
+					Phonize(SH);
+				else if (Next_Letter == 'H')
+				{
+					Phonize(TH);
+					skip_letter++;
+				}
+				else
+					Phonize('T');
+				break;
+				/* F */
+			case 'V':
+				Phonize('F');
+				break;
+				/* W before a vowel, else dropped */
+			case 'W':
+				if (isvowel(Next_Letter))
+					Phonize('W');
+				break;
+				/* KS */
+			case 'X':
+				Phonize('K');
+				if (max_phonemes == 0 || Phone_Len < max_phonemes)
+					Phonize('S');
+				break;
+				/* Y if followed by a vowel */
+			case 'Y':
+				if (isvowel(Next_Letter))
+					Phonize('Y');
+				break;
+				/* S */
+			case 'Z':
+				Phonize('S');
+				break;
+				/* No transformation */
+			case 'F':
+			case 'J':
+			case 'L':
+			case 'M':
+			case 'N':
+			case 'R':
+				Phonize(Curr_Letter);
+				break;
+			default:
+				/* nothing */
+				break;
+		}						/* END SWITCH */
+
+		w_idx += skip_letter;
+	}							/* END FOR */
+
+	End_Phoned_Word;
+}								/* END metaphone */
+
+
+/*
+ * SQL function: soundex(text) returns text
+ */
+PG_FUNCTION_INFO_V1(soundex);
+
+Datum
+soundex(PG_FUNCTION_ARGS)
+{
+	char		outstr[SOUNDEX_LEN + 1];
+	char	   *arg;
+
+	arg = text_to_cstring(PG_GETARG_TEXT_PP(0));
+
+	_soundex(arg, outstr);
+
+	PG_RETURN_TEXT_P(cstring_to_text(outstr));
+}
+
+static void
+_soundex(const char *instr, char *outstr)
+{
+	int			count;
+
+	AssertArg(instr);
+	AssertArg(outstr);
+
+	outstr[SOUNDEX_LEN] = '\0';
+
+	/* Skip leading non-alphabetic characters */
+	while (!isalpha((unsigned char) instr[0]) && instr[0])
+		++instr;
+
+	/* No string left */
+	if (!instr[0])
+	{
+		outstr[0] = (char) 0;
+		return;
+	}
+
+	/* Take the first letter as is */
+	*outstr++ = (char) toupper((unsigned char) *instr++);
+
+	count = 1;
+	while (*instr && count < SOUNDEX_LEN)
+	{
+		if (isalpha((unsigned char) *instr) &&
+			soundex_code(*instr) != soundex_code(*(instr - 1)))
+		{
+			*outstr = soundex_code(instr[0]);
+			if (*outstr != '0')
+			{
+				++outstr;
+				++count;
+			}
+		}
+		++instr;
+	}
+
+	/* Fill with 0's */
+	while (count < SOUNDEX_LEN)
+	{
+		*outstr = '0';
+		++outstr;
+		++count;
+	}
+}
+
+PG_FUNCTION_INFO_V1(difference);
+
+Datum
+difference(PG_FUNCTION_ARGS)
+{
+	char		sndx1[SOUNDEX_LEN + 1],
+				sndx2[SOUNDEX_LEN + 1];
+	int			i,
+				result;
+
+	_soundex(text_to_cstring(PG_GETARG_TEXT_PP(0)), sndx1);
+	_soundex(text_to_cstring(PG_GETARG_TEXT_PP(1)), sndx2);
+
+	result = 0;
+	for (i = 0; i < SOUNDEX_LEN; i++)
+	{
+		if (sndx1[i] == sndx2[i])
+			result++;
+	}
+
+	PG_RETURN_INT32(result);
+}
diff --git a/contrib/fuzzystrmatch/fuzzystrmatch.control b/contrib/fuzzystrmatch/fuzzystrmatch.control
new file mode 100644
index 0000000..3cd6660
--- /dev/null
+++ b/contrib/fuzzystrmatch/fuzzystrmatch.control
@@ -0,0 +1,6 @@
+# fuzzystrmatch extension
+comment = 'determine similarities and distance between strings'
+default_version = '1.1'
+module_pathname = '$libdir/fuzzystrmatch'
+relocatable = true
+trusted = true
diff --git a/contrib/fuzzystrmatch/sql/fuzzystrmatch.sql b/contrib/fuzzystrmatch/sql/fuzzystrmatch.sql
new file mode 100644
index 0000000..f05dc28
--- /dev/null
+++ b/contrib/fuzzystrmatch/sql/fuzzystrmatch.sql
@@ -0,0 +1,21 @@
+CREATE EXTENSION fuzzystrmatch;
+
+
+SELECT soundex('hello world!');
+
+SELECT soundex('Anne'), soundex('Ann'), difference('Anne', 'Ann');
+SELECT soundex('Anne'), soundex('Andrew'), difference('Anne', 'Andrew');
+SELECT soundex('Anne'), soundex('Margaret'), difference('Anne', 'Margaret');
+
+
+SELECT levenshtein('GUMBO', 'GAMBOL');
+SELECT levenshtein('GUMBO', 'GAMBOL', 2, 1, 1);
+SELECT levenshtein_less_equal('extensive', 'exhaustive', 2);
+SELECT levenshtein_less_equal('extensive', 'exhaustive', 4);
+
+
+SELECT metaphone('GUMBO', 4);
+
+
+SELECT dmetaphone('gumbo');
+SELECT dmetaphone_alt('gumbo');