Adding upstream version 14.5.upstream/14.5upstream

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

11 files changed, 2425 insertions, 0 deletions

diff --git a/contrib/tablefunc/.gitignore b/contrib/tablefunc/.gitignore
new file mode 100644
index 0000000..5dcb3ff
--- /dev/null
+++ b/contrib/tablefunc/.gitignore
@@ -0,0 +1,4 @@
+# Generated subdirectories
+/log/
+/results/
+/tmp_check/
diff --git a/contrib/tablefunc/Makefile b/contrib/tablefunc/Makefile
new file mode 100644
index 0000000..191a3a1
--- /dev/null
+++ b/contrib/tablefunc/Makefile
@@ -0,0 +1,22 @@
+# contrib/tablefunc/Makefile
+
+MODULES = tablefunc
+
+EXTENSION = tablefunc
+DATA = tablefunc--1.0.sql
+PGFILEDESC = "tablefunc - various functions that return tables"
+
+REGRESS = tablefunc
+
+LDFLAGS_SL += $(filter -lm, $(LIBS))
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = contrib/tablefunc
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/contrib/tablefunc/data/connectby_int.data b/contrib/tablefunc/data/connectby_int.data
new file mode 100644
index 0000000..c061be3
--- /dev/null
+++ b/contrib/tablefunc/data/connectby_int.data
@@ -0,0 +1,9 @@
+1	\N
+2	1
+3	1
+4	2
+5	2
+6	4
+7	3
+8	6
+9	5
diff --git a/contrib/tablefunc/data/connectby_text.data b/contrib/tablefunc/data/connectby_text.data
new file mode 100644
index 0000000..a903820
--- /dev/null
+++ b/contrib/tablefunc/data/connectby_text.data
@@ -0,0 +1,9 @@
+row1	\N	0
+row2	row1	0
+row3	row1	0
+row4	row2	1
+row5	row2	0
+row6	row4	0
+row7	row3	0
+row8	row6	0
+row9	row5	0
diff --git a/contrib/tablefunc/data/ct.data b/contrib/tablefunc/data/ct.data
new file mode 100644
index 0000000..7733fc2
--- /dev/null
+++ b/contrib/tablefunc/data/ct.data
@@ -0,0 +1,18 @@
+1	group1	test1	att1	val1
+2	group1	test1	att2	val2
+3	group1	test1	att3	val3
+4	group1	test1	att4	val4
+5	group1	test2	att1	val5
+6	group1	test2	att2	val6
+7	group1	test2	att3	val7
+8	group1	test2	att4	val8
+9	group2	test3	att1	val1
+10	group2	test3	att2	val2
+11	group2	test3	att3	val3
+12	group2	test4	att1	val4
+13	group2	test4	att2	val5
+14	group2	test4	att3	val6
+15	group1	\N	att1	val9
+16	group1	\N	att2	val10
+17	group1	\N	att3	val11
+18	group1	\N	att4	val12
diff --git a/contrib/tablefunc/expected/tablefunc.out b/contrib/tablefunc/expected/tablefunc.out
new file mode 100644
index 0000000..464c210
--- /dev/null
+++ b/contrib/tablefunc/expected/tablefunc.out
@@ -0,0 +1,430 @@
+CREATE EXTENSION tablefunc;
+--
+-- normal_rand()
+-- no easy way to do this for regression testing
+--
+SELECT avg(normal_rand)::int, count(*) FROM normal_rand(100, 250, 0.2);
+ avg | count 
+-----+-------
+ 250 |   100
+(1 row)
+
+-- negative number of tuples
+SELECT avg(normal_rand)::int, count(*) FROM normal_rand(-1, 250, 0.2);
+ERROR:  number of rows cannot be negative
+--
+-- crosstab()
+--
+CREATE TABLE ct(id int, rowclass text, rowid text, attribute text, val text);
+\copy ct from 'data/ct.data'
+SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' and (attribute = ''att2'' or attribute = ''att3'') ORDER BY 1,2;');
+ row_name | category_1 | category_2 
+----------+------------+------------
+ test1    | val2       | val3
+ test2    | val6       | val7
+          | val10      | val11
+(3 rows)
+
+SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' and (attribute = ''att2'' or attribute = ''att3'') ORDER BY 1,2;');
+ row_name | category_1 | category_2 | category_3 
+----------+------------+------------+------------
+ test1    | val2       | val3       | 
+ test2    | val6       | val7       | 
+          | val10      | val11      | 
+(3 rows)
+
+SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' and (attribute = ''att2'' or attribute = ''att3'') ORDER BY 1,2;');
+ row_name | category_1 | category_2 | category_3 | category_4 
+----------+------------+------------+------------+------------
+ test1    | val2       | val3       |            | 
+ test2    | val6       | val7       |            | 
+          | val10      | val11      |            | 
+(3 rows)
+
+SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
+ row_name | category_1 | category_2 
+----------+------------+------------
+ test1    | val1       | val2
+ test2    | val5       | val6
+          | val9       | val10
+(3 rows)
+
+SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
+ row_name | category_1 | category_2 | category_3 
+----------+------------+------------+------------
+ test1    | val1       | val2       | val3
+ test2    | val5       | val6       | val7
+          | val9       | val10      | val11
+(3 rows)
+
+SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
+ row_name | category_1 | category_2 | category_3 | category_4 
+----------+------------+------------+------------+------------
+ test1    | val1       | val2       | val3       | val4
+ test2    | val5       | val6       | val7       | val8
+          | val9       | val10      | val11      | val12
+(3 rows)
+
+SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' and (attribute = ''att1'' or attribute = ''att2'') ORDER BY 1,2;');
+ row_name | category_1 | category_2 
+----------+------------+------------
+ test3    | val1       | val2
+ test4    | val4       | val5
+(2 rows)
+
+SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' and (attribute = ''att1'' or attribute = ''att2'') ORDER BY 1,2;');
+ row_name | category_1 | category_2 | category_3 
+----------+------------+------------+------------
+ test3    | val1       | val2       | 
+ test4    | val4       | val5       | 
+(2 rows)
+
+SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' and (attribute = ''att1'' or attribute = ''att2'') ORDER BY 1,2;');
+ row_name | category_1 | category_2 | category_3 | category_4 
+----------+------------+------------+------------+------------
+ test3    | val1       | val2       |            | 
+ test4    | val4       | val5       |            | 
+(2 rows)
+
+SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' ORDER BY 1,2;');
+ row_name | category_1 | category_2 
+----------+------------+------------
+ test3    | val1       | val2
+ test4    | val4       | val5
+(2 rows)
+
+SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' ORDER BY 1,2;');
+ row_name | category_1 | category_2 | category_3 
+----------+------------+------------+------------
+ test3    | val1       | val2       | val3
+ test4    | val4       | val5       | val6
+(2 rows)
+
+SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' ORDER BY 1,2;');
+ row_name | category_1 | category_2 | category_3 | category_4 
+----------+------------+------------+------------+------------
+ test3    | val1       | val2       | val3       | 
+ test4    | val4       | val5       | val6       | 
+(2 rows)
+
+SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text);
+ rowid | att1 | att2  
+-------+------+-------
+ test1 | val1 | val2
+ test2 | val5 | val6
+       | val9 | val10
+(3 rows)
+
+SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text, att3 text);
+ rowid | att1 | att2  | att3  
+-------+------+-------+-------
+ test1 | val1 | val2  | val3
+ test2 | val5 | val6  | val7
+       | val9 | val10 | val11
+(3 rows)
+
+SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text, att3 text, att4 text);
+ rowid | att1 | att2  | att3  | att4  
+-------+------+-------+-------+-------
+ test1 | val1 | val2  | val3  | val4
+ test2 | val5 | val6  | val7  | val8
+       | val9 | val10 | val11 | val12
+(3 rows)
+
+-- check it works with OUT parameters, too
+CREATE FUNCTION crosstab_out(text,
+	OUT rowid text, OUT att1 text, OUT att2 text, OUT att3 text)
+RETURNS setof record
+AS '$libdir/tablefunc','crosstab'
+LANGUAGE C STABLE STRICT;
+SELECT * FROM crosstab_out('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
+ rowid | att1 | att2  | att3  
+-------+------+-------+-------
+ test1 | val1 | val2  | val3
+ test2 | val5 | val6  | val7
+       | val9 | val10 | val11
+(3 rows)
+
+--
+-- hash based crosstab
+--
+create table cth(id serial, rowid text, rowdt timestamp, attribute text, val text);
+insert into cth values(DEFAULT,'test1','01 March 2003','temperature','42');
+insert into cth values(DEFAULT,'test1','01 March 2003','test_result','PASS');
+-- the next line is intentionally left commented and is therefore a "missing" attribute
+-- insert into cth values(DEFAULT,'test1','01 March 2003','test_startdate','28 February 2003');
+insert into cth values(DEFAULT,'test1','01 March 2003','volts','2.6987');
+insert into cth values(DEFAULT,'test2','02 March 2003','temperature','53');
+insert into cth values(DEFAULT,'test2','02 March 2003','test_result','FAIL');
+insert into cth values(DEFAULT,'test2','02 March 2003','test_startdate','01 March 2003');
+insert into cth values(DEFAULT,'test2','02 March 2003','volts','3.1234');
+-- next group tests for NULL rowids
+insert into cth values(DEFAULT,NULL,'25 October 2007','temperature','57');
+insert into cth values(DEFAULT,NULL,'25 October 2007','test_result','PASS');
+insert into cth values(DEFAULT,NULL,'25 October 2007','test_startdate','24 October 2007');
+insert into cth values(DEFAULT,NULL,'25 October 2007','volts','1.41234');
+-- return attributes as plain text
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1')
+AS c(rowid text, rowdt timestamp, temperature text, test_result text, test_startdate text, volts text);
+ rowid |          rowdt           | temperature | test_result | test_startdate  |  volts  
+-------+--------------------------+-------------+-------------+-----------------+---------
+ test1 | Sat Mar 01 00:00:00 2003 | 42          | PASS        |                 | 2.6987
+ test2 | Sun Mar 02 00:00:00 2003 | 53          | FAIL        | 01 March 2003   | 3.1234
+       | Thu Oct 25 00:00:00 2007 | 57          | PASS        | 24 October 2007 | 1.41234
+(3 rows)
+
+-- this time without rowdt
+SELECT * FROM crosstab(
+  'SELECT rowid, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1')
+AS c(rowid text, temperature text, test_result text, test_startdate text, volts text);
+ rowid | temperature | test_result | test_startdate  |  volts  
+-------+-------------+-------------+-----------------+---------
+ test1 | 42          | PASS        |                 | 2.6987
+ test2 | 53          | FAIL        | 01 March 2003   | 3.1234
+       | 57          | PASS        | 24 October 2007 | 1.41234
+(3 rows)
+
+-- convert attributes to specific datatypes
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1')
+AS c(rowid text, rowdt timestamp, temperature int4, test_result text, test_startdate timestamp, volts float8);
+ rowid |          rowdt           | temperature | test_result |      test_startdate      |  volts  
+-------+--------------------------+-------------+-------------+--------------------------+---------
+ test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |                          |  2.6987
+ test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003 |  3.1234
+       | Thu Oct 25 00:00:00 2007 |          57 | PASS        | Wed Oct 24 00:00:00 2007 | 1.41234
+(3 rows)
+
+-- source query and category query out of sync
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth WHERE attribute IN (''temperature'',''test_result'',''test_startdate'') ORDER BY 1')
+AS c(rowid text, rowdt timestamp, temperature int4, test_result text, test_startdate timestamp);
+ rowid |          rowdt           | temperature | test_result |      test_startdate      
+-------+--------------------------+-------------+-------------+--------------------------
+ test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        | 
+ test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003
+       | Thu Oct 25 00:00:00 2007 |          57 | PASS        | Wed Oct 24 00:00:00 2007
+(3 rows)
+
+-- if category query generates no rows, get expected error
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth WHERE attribute = ''a'' ORDER BY 1')
+AS c(rowid text, rowdt timestamp, temperature int4, test_result text, test_startdate timestamp, volts float8);
+ERROR:  provided "categories" SQL must return 1 column of at least one row
+-- if category query generates more than one column, get expected error
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT rowdt, attribute FROM cth ORDER BY 2')
+AS c(rowid text, rowdt timestamp, temperature int4, test_result text, test_startdate timestamp, volts float8);
+ERROR:  provided "categories" SQL must return 1 column of at least one row
+-- if source query returns zero rows, get zero rows returned
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth WHERE false ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1')
+AS c(rowid text, rowdt timestamp, temperature text, test_result text, test_startdate text, volts text);
+ rowid | rowdt | temperature | test_result | test_startdate | volts 
+-------+-------+-------------+-------------+----------------+-------
+(0 rows)
+
+-- if source query returns zero rows, get zero rows returned even if category query generates no rows
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth WHERE false ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth WHERE false ORDER BY 1')
+AS c(rowid text, rowdt timestamp, temperature text, test_result text, test_startdate text, volts text);
+ rowid | rowdt | temperature | test_result | test_startdate | volts 
+-------+-------+-------------+-------------+----------------+-------
+(0 rows)
+
+-- check it works with a named result rowtype
+create type my_crosstab_result as (
+  rowid text, rowdt timestamp,
+  temperature int4, test_result text, test_startdate timestamp, volts float8);
+CREATE FUNCTION crosstab_named(text, text)
+RETURNS setof my_crosstab_result
+AS '$libdir/tablefunc','crosstab_hash'
+LANGUAGE C STABLE STRICT;
+SELECT * FROM crosstab_named(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1');
+ rowid |          rowdt           | temperature | test_result |      test_startdate      |  volts  
+-------+--------------------------+-------------+-------------+--------------------------+---------
+ test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |                          |  2.6987
+ test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003 |  3.1234
+       | Thu Oct 25 00:00:00 2007 |          57 | PASS        | Wed Oct 24 00:00:00 2007 | 1.41234
+(3 rows)
+
+-- check it works with OUT parameters
+CREATE FUNCTION crosstab_out(text, text,
+  OUT rowid text, OUT rowdt timestamp,
+  OUT temperature int4, OUT test_result text,
+  OUT test_startdate timestamp, OUT volts float8)
+RETURNS setof record
+AS '$libdir/tablefunc','crosstab_hash'
+LANGUAGE C STABLE STRICT;
+SELECT * FROM crosstab_out(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1');
+ rowid |          rowdt           | temperature | test_result |      test_startdate      |  volts  
+-------+--------------------------+-------------+-------------+--------------------------+---------
+ test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |                          |  2.6987
+ test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003 |  3.1234
+       | Thu Oct 25 00:00:00 2007 |          57 | PASS        | Wed Oct 24 00:00:00 2007 | 1.41234
+(3 rows)
+
+--
+-- connectby
+--
+-- test connectby with text based hierarchy
+CREATE TABLE connectby_text(keyid text, parent_keyid text, pos int);
+\copy connectby_text from 'data/connectby_text.data'
+-- with branch, without orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text);
+ keyid | parent_keyid | level |       branch        
+-------+--------------+-------+---------------------
+ row2  |              |     0 | row2
+ row4  | row2         |     1 | row2~row4
+ row6  | row4         |     2 | row2~row4~row6
+ row8  | row6         |     3 | row2~row4~row6~row8
+ row5  | row2         |     1 | row2~row5
+ row9  | row5         |     2 | row2~row5~row9
+(6 rows)
+
+-- without branch, without orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0) AS t(keyid text, parent_keyid text, level int);
+ keyid | parent_keyid | level 
+-------+--------------+-------
+ row2  |              |     0
+ row4  | row2         |     1
+ row6  | row4         |     2
+ row8  | row6         |     3
+ row5  | row2         |     1
+ row9  | row5         |     2
+(6 rows)
+
+-- with branch, with orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text, pos int) ORDER BY t.pos;
+ keyid | parent_keyid | level |       branch        | pos 
+-------+--------------+-------+---------------------+-----
+ row2  |              |     0 | row2                |   1
+ row5  | row2         |     1 | row2~row5           |   2
+ row9  | row5         |     2 | row2~row5~row9      |   3
+ row4  | row2         |     1 | row2~row4           |   4
+ row6  | row4         |     2 | row2~row4~row6      |   5
+ row8  | row6         |     3 | row2~row4~row6~row8 |   6
+(6 rows)
+
+-- without branch, with orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'pos', 'row2', 0) AS t(keyid text, parent_keyid text, level int, pos int) ORDER BY t.pos;
+ keyid | parent_keyid | level | pos 
+-------+--------------+-------+-----
+ row2  |              |     0 |   1
+ row5  | row2         |     1 |   2
+ row9  | row5         |     2 |   3
+ row4  | row2         |     1 |   4
+ row6  | row4         |     2 |   5
+ row8  | row6         |     3 |   6
+(6 rows)
+
+-- test connectby with int based hierarchy
+CREATE TABLE connectby_int(keyid int, parent_keyid int);
+\copy connectby_int from 'data/connectby_int.data'
+-- with branch
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '2', 0, '~') AS t(keyid int, parent_keyid int, level int, branch text);
+ keyid | parent_keyid | level | branch  
+-------+--------------+-------+---------
+     2 |              |     0 | 2
+     4 |            2 |     1 | 2~4
+     6 |            4 |     2 | 2~4~6
+     8 |            6 |     3 | 2~4~6~8
+     5 |            2 |     1 | 2~5
+     9 |            5 |     2 | 2~5~9
+(6 rows)
+
+-- without branch
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '2', 0) AS t(keyid int, parent_keyid int, level int);
+ keyid | parent_keyid | level 
+-------+--------------+-------
+     2 |              |     0
+     4 |            2 |     1
+     6 |            4 |     2
+     8 |            6 |     3
+     5 |            2 |     1
+     9 |            5 |     2
+(6 rows)
+
+-- recursion detection
+INSERT INTO connectby_int VALUES(10,9);
+INSERT INTO connectby_int VALUES(11,10);
+INSERT INTO connectby_int VALUES(9,11);
+-- should fail due to infinite recursion
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '2', 0, '~') AS t(keyid int, parent_keyid int, level int, branch text);
+ERROR:  infinite recursion detected
+-- infinite recursion failure avoided by depth limit
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '2', 4, '~') AS t(keyid int, parent_keyid int, level int, branch text);
+ keyid | parent_keyid | level |   branch    
+-------+--------------+-------+-------------
+     2 |              |     0 | 2
+     4 |            2 |     1 | 2~4
+     6 |            4 |     2 | 2~4~6
+     8 |            6 |     3 | 2~4~6~8
+     5 |            2 |     1 | 2~5
+     9 |            5 |     2 | 2~5~9
+    10 |            9 |     3 | 2~5~9~10
+    11 |           10 |     4 | 2~5~9~10~11
+(8 rows)
+
+-- should fail as first two columns must have the same type
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '2', 0, '~') AS t(keyid text, parent_keyid int, level int, branch text);
+ERROR:  invalid return type
+DETAIL:  First two columns must be the same type.
+-- should fail as key field datatype should match return datatype
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '2', 0, '~') AS t(keyid float8, parent_keyid float8, level int, branch text);
+ERROR:  invalid return type
+DETAIL:  SQL key field type double precision does not match return key field type integer.
+-- tests for values using custom queries
+-- query with one column - failed
+SELECT * FROM connectby('connectby_int', '1; --', 'parent_keyid', '2', 0) AS t(keyid int, parent_keyid int, level int);
+ERROR:  invalid return type
+DETAIL:  Query must return at least two columns.
+-- query with two columns first value as NULL
+SELECT * FROM connectby('connectby_int', 'NULL::int, 1::int; --', 'parent_keyid', '2', 0) AS t(keyid int, parent_keyid int, level int);
+ keyid | parent_keyid | level 
+-------+--------------+-------
+     2 |              |     0
+       |            1 |     1
+(2 rows)
+
+-- query with two columns second value as NULL
+SELECT * FROM connectby('connectby_int', '1::int, NULL::int; --', 'parent_keyid', '2', 0) AS t(keyid int, parent_keyid int, level int);
+ERROR:  infinite recursion detected
+-- query with two columns, both values as NULL
+SELECT * FROM connectby('connectby_int', 'NULL::int, NULL::int; --', 'parent_keyid', '2', 0) AS t(keyid int, parent_keyid int, level int);
+ keyid | parent_keyid | level 
+-------+--------------+-------
+     2 |              |     0
+       |              |     1
+(2 rows)
+
+-- test for falsely detected recursion
+DROP TABLE connectby_int;
+CREATE TABLE connectby_int(keyid int, parent_keyid int);
+INSERT INTO connectby_int VALUES(11,NULL);
+INSERT INTO connectby_int VALUES(10,11);
+INSERT INTO connectby_int VALUES(111,11);
+INSERT INTO connectby_int VALUES(1,111);
+-- this should not fail due to recursion detection
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '11', 0, '-') AS t(keyid int, parent_keyid int, level int, branch text);
+ keyid | parent_keyid | level |  branch  
+-------+--------------+-------+----------
+    11 |              |     0 | 11
+    10 |           11 |     1 | 11-10
+   111 |           11 |     1 | 11-111
+     1 |          111 |     2 | 11-111-1
+(4 rows)
+
diff --git a/contrib/tablefunc/sql/tablefunc.sql b/contrib/tablefunc/sql/tablefunc.sql
new file mode 100644
index 0000000..02e8a98
--- /dev/null
+++ b/contrib/tablefunc/sql/tablefunc.sql
@@ -0,0 +1,208 @@
+CREATE EXTENSION tablefunc;
+
+--
+-- normal_rand()
+-- no easy way to do this for regression testing
+--
+SELECT avg(normal_rand)::int, count(*) FROM normal_rand(100, 250, 0.2);
+-- negative number of tuples
+SELECT avg(normal_rand)::int, count(*) FROM normal_rand(-1, 250, 0.2);
+
+--
+-- crosstab()
+--
+CREATE TABLE ct(id int, rowclass text, rowid text, attribute text, val text);
+\copy ct from 'data/ct.data'
+
+SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' and (attribute = ''att2'' or attribute = ''att3'') ORDER BY 1,2;');
+SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' and (attribute = ''att2'' or attribute = ''att3'') ORDER BY 1,2;');
+SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' and (attribute = ''att2'' or attribute = ''att3'') ORDER BY 1,2;');
+
+SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
+SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
+SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
+
+SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' and (attribute = ''att1'' or attribute = ''att2'') ORDER BY 1,2;');
+SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' and (attribute = ''att1'' or attribute = ''att2'') ORDER BY 1,2;');
+SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' and (attribute = ''att1'' or attribute = ''att2'') ORDER BY 1,2;');
+
+SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' ORDER BY 1,2;');
+SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' ORDER BY 1,2;');
+SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' ORDER BY 1,2;');
+
+SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text);
+SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text, att3 text);
+SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text, att3 text, att4 text);
+
+-- check it works with OUT parameters, too
+
+CREATE FUNCTION crosstab_out(text,
+	OUT rowid text, OUT att1 text, OUT att2 text, OUT att3 text)
+RETURNS setof record
+AS '$libdir/tablefunc','crosstab'
+LANGUAGE C STABLE STRICT;
+
+SELECT * FROM crosstab_out('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
+
+--
+-- hash based crosstab
+--
+create table cth(id serial, rowid text, rowdt timestamp, attribute text, val text);
+insert into cth values(DEFAULT,'test1','01 March 2003','temperature','42');
+insert into cth values(DEFAULT,'test1','01 March 2003','test_result','PASS');
+-- the next line is intentionally left commented and is therefore a "missing" attribute
+-- insert into cth values(DEFAULT,'test1','01 March 2003','test_startdate','28 February 2003');
+insert into cth values(DEFAULT,'test1','01 March 2003','volts','2.6987');
+insert into cth values(DEFAULT,'test2','02 March 2003','temperature','53');
+insert into cth values(DEFAULT,'test2','02 March 2003','test_result','FAIL');
+insert into cth values(DEFAULT,'test2','02 March 2003','test_startdate','01 March 2003');
+insert into cth values(DEFAULT,'test2','02 March 2003','volts','3.1234');
+-- next group tests for NULL rowids
+insert into cth values(DEFAULT,NULL,'25 October 2007','temperature','57');
+insert into cth values(DEFAULT,NULL,'25 October 2007','test_result','PASS');
+insert into cth values(DEFAULT,NULL,'25 October 2007','test_startdate','24 October 2007');
+insert into cth values(DEFAULT,NULL,'25 October 2007','volts','1.41234');
+
+-- return attributes as plain text
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1')
+AS c(rowid text, rowdt timestamp, temperature text, test_result text, test_startdate text, volts text);
+
+-- this time without rowdt
+SELECT * FROM crosstab(
+  'SELECT rowid, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1')
+AS c(rowid text, temperature text, test_result text, test_startdate text, volts text);
+
+-- convert attributes to specific datatypes
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1')
+AS c(rowid text, rowdt timestamp, temperature int4, test_result text, test_startdate timestamp, volts float8);
+
+-- source query and category query out of sync
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth WHERE attribute IN (''temperature'',''test_result'',''test_startdate'') ORDER BY 1')
+AS c(rowid text, rowdt timestamp, temperature int4, test_result text, test_startdate timestamp);
+
+-- if category query generates no rows, get expected error
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth WHERE attribute = ''a'' ORDER BY 1')
+AS c(rowid text, rowdt timestamp, temperature int4, test_result text, test_startdate timestamp, volts float8);
+
+-- if category query generates more than one column, get expected error
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT rowdt, attribute FROM cth ORDER BY 2')
+AS c(rowid text, rowdt timestamp, temperature int4, test_result text, test_startdate timestamp, volts float8);
+
+-- if source query returns zero rows, get zero rows returned
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth WHERE false ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1')
+AS c(rowid text, rowdt timestamp, temperature text, test_result text, test_startdate text, volts text);
+
+-- if source query returns zero rows, get zero rows returned even if category query generates no rows
+SELECT * FROM crosstab(
+  'SELECT rowid, rowdt, attribute, val FROM cth WHERE false ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth WHERE false ORDER BY 1')
+AS c(rowid text, rowdt timestamp, temperature text, test_result text, test_startdate text, volts text);
+
+-- check it works with a named result rowtype
+
+create type my_crosstab_result as (
+  rowid text, rowdt timestamp,
+  temperature int4, test_result text, test_startdate timestamp, volts float8);
+
+CREATE FUNCTION crosstab_named(text, text)
+RETURNS setof my_crosstab_result
+AS '$libdir/tablefunc','crosstab_hash'
+LANGUAGE C STABLE STRICT;
+
+SELECT * FROM crosstab_named(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1');
+
+-- check it works with OUT parameters
+
+CREATE FUNCTION crosstab_out(text, text,
+  OUT rowid text, OUT rowdt timestamp,
+  OUT temperature int4, OUT test_result text,
+  OUT test_startdate timestamp, OUT volts float8)
+RETURNS setof record
+AS '$libdir/tablefunc','crosstab_hash'
+LANGUAGE C STABLE STRICT;
+
+SELECT * FROM crosstab_out(
+  'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
+  'SELECT DISTINCT attribute FROM cth ORDER BY 1');
+
+--
+-- connectby
+--
+
+-- test connectby with text based hierarchy
+CREATE TABLE connectby_text(keyid text, parent_keyid text, pos int);
+\copy connectby_text from 'data/connectby_text.data'
+
+-- with branch, without orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text);
+
+-- without branch, without orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0) AS t(keyid text, parent_keyid text, level int);
+
+-- with branch, with orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text, pos int) ORDER BY t.pos;
+
+-- without branch, with orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'pos', 'row2', 0) AS t(keyid text, parent_keyid text, level int, pos int) ORDER BY t.pos;
+
+-- test connectby with int based hierarchy
+CREATE TABLE connectby_int(keyid int, parent_keyid int);
+\copy connectby_int from 'data/connectby_int.data'
+
+-- with branch
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '2', 0, '~') AS t(keyid int, parent_keyid int, level int, branch text);
+
+-- without branch
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '2', 0) AS t(keyid int, parent_keyid int, level int);
+
+-- recursion detection
+INSERT INTO connectby_int VALUES(10,9);
+INSERT INTO connectby_int VALUES(11,10);
+INSERT INTO connectby_int VALUES(9,11);
+
+-- should fail due to infinite recursion
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '2', 0, '~') AS t(keyid int, parent_keyid int, level int, branch text);
+
+-- infinite recursion failure avoided by depth limit
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '2', 4, '~') AS t(keyid int, parent_keyid int, level int, branch text);
+
+-- should fail as first two columns must have the same type
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '2', 0, '~') AS t(keyid text, parent_keyid int, level int, branch text);
+
+-- should fail as key field datatype should match return datatype
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '2', 0, '~') AS t(keyid float8, parent_keyid float8, level int, branch text);
+
+-- tests for values using custom queries
+-- query with one column - failed
+SELECT * FROM connectby('connectby_int', '1; --', 'parent_keyid', '2', 0) AS t(keyid int, parent_keyid int, level int);
+-- query with two columns first value as NULL
+SELECT * FROM connectby('connectby_int', 'NULL::int, 1::int; --', 'parent_keyid', '2', 0) AS t(keyid int, parent_keyid int, level int);
+-- query with two columns second value as NULL
+SELECT * FROM connectby('connectby_int', '1::int, NULL::int; --', 'parent_keyid', '2', 0) AS t(keyid int, parent_keyid int, level int);
+-- query with two columns, both values as NULL
+SELECT * FROM connectby('connectby_int', 'NULL::int, NULL::int; --', 'parent_keyid', '2', 0) AS t(keyid int, parent_keyid int, level int);
+
+-- test for falsely detected recursion
+DROP TABLE connectby_int;
+CREATE TABLE connectby_int(keyid int, parent_keyid int);
+INSERT INTO connectby_int VALUES(11,NULL);
+INSERT INTO connectby_int VALUES(10,11);
+INSERT INTO connectby_int VALUES(111,11);
+INSERT INTO connectby_int VALUES(1,111);
+-- this should not fail due to recursion detection
+SELECT * FROM connectby('connectby_int', 'keyid', 'parent_keyid', '11', 0, '-') AS t(keyid int, parent_keyid int, level int, branch text);
diff --git a/contrib/tablefunc/tablefunc--1.0.sql b/contrib/tablefunc/tablefunc--1.0.sql
new file mode 100644
index 0000000..8681ff4
--- /dev/null
+++ b/contrib/tablefunc/tablefunc--1.0.sql
@@ -0,0 +1,88 @@
+/* contrib/tablefunc/tablefunc--1.0.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION tablefunc" to load this file. \quit
+
+CREATE FUNCTION normal_rand(int4, float8, float8)
+RETURNS setof float8
+AS 'MODULE_PATHNAME','normal_rand'
+LANGUAGE C VOLATILE STRICT;
+
+-- the generic crosstab function:
+CREATE FUNCTION crosstab(text)
+RETURNS setof record
+AS 'MODULE_PATHNAME','crosstab'
+LANGUAGE C STABLE STRICT;
+
+-- examples of building custom type-specific crosstab functions:
+CREATE TYPE tablefunc_crosstab_2 AS
+(
+	row_name TEXT,
+	category_1 TEXT,
+	category_2 TEXT
+);
+
+CREATE TYPE tablefunc_crosstab_3 AS
+(
+	row_name TEXT,
+	category_1 TEXT,
+	category_2 TEXT,
+	category_3 TEXT
+);
+
+CREATE TYPE tablefunc_crosstab_4 AS
+(
+	row_name TEXT,
+	category_1 TEXT,
+	category_2 TEXT,
+	category_3 TEXT,
+	category_4 TEXT
+);
+
+CREATE FUNCTION crosstab2(text)
+RETURNS setof tablefunc_crosstab_2
+AS 'MODULE_PATHNAME','crosstab'
+LANGUAGE C STABLE STRICT;
+
+CREATE FUNCTION crosstab3(text)
+RETURNS setof tablefunc_crosstab_3
+AS 'MODULE_PATHNAME','crosstab'
+LANGUAGE C STABLE STRICT;
+
+CREATE FUNCTION crosstab4(text)
+RETURNS setof tablefunc_crosstab_4
+AS 'MODULE_PATHNAME','crosstab'
+LANGUAGE C STABLE STRICT;
+
+-- obsolete:
+CREATE FUNCTION crosstab(text,int)
+RETURNS setof record
+AS 'MODULE_PATHNAME','crosstab'
+LANGUAGE C STABLE STRICT;
+
+CREATE FUNCTION crosstab(text,text)
+RETURNS setof record
+AS 'MODULE_PATHNAME','crosstab_hash'
+LANGUAGE C STABLE STRICT;
+
+CREATE FUNCTION connectby(text,text,text,text,int,text)
+RETURNS setof record
+AS 'MODULE_PATHNAME','connectby_text'
+LANGUAGE C STABLE STRICT;
+
+CREATE FUNCTION connectby(text,text,text,text,int)
+RETURNS setof record
+AS 'MODULE_PATHNAME','connectby_text'
+LANGUAGE C STABLE STRICT;
+
+-- These 2 take the name of a field to ORDER BY as 4th arg (for sorting siblings)
+
+CREATE FUNCTION connectby(text,text,text,text,text,int,text)
+RETURNS setof record
+AS 'MODULE_PATHNAME','connectby_text_serial'
+LANGUAGE C STABLE STRICT;
+
+CREATE FUNCTION connectby(text,text,text,text,text,int)
+RETURNS setof record
+AS 'MODULE_PATHNAME','connectby_text_serial'
+LANGUAGE C STABLE STRICT;
diff --git a/contrib/tablefunc/tablefunc.c b/contrib/tablefunc/tablefunc.c
new file mode 100644
index 0000000..779bd44
--- /dev/null
+++ b/contrib/tablefunc/tablefunc.c
@@ -0,0 +1,1592 @@
+/*
+ * contrib/tablefunc/tablefunc.c
+ *
+ *
+ * tablefunc
+ *
+ * Sample to demonstrate C functions which return setof scalar
+ * and setof composite.
+ * Joe Conway <mail@joeconway.com>
+ * And contributors:
+ * Nabil Sayegh <postgresql@e-trolley.de>
+ *
+ * Copyright (c) 2002-2021, PostgreSQL Global Development Group
+ *
+ * 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 <math.h>
+
+#include "access/htup_details.h"
+#include "catalog/pg_type.h"
+#include "executor/spi.h"
+#include "funcapi.h"
+#include "lib/stringinfo.h"
+#include "miscadmin.h"
+#include "tablefunc.h"
+#include "utils/builtins.h"
+
+PG_MODULE_MAGIC;
+
+static HTAB *load_categories_hash(char *cats_sql, MemoryContext per_query_ctx);
+static Tuplestorestate *get_crosstab_tuplestore(char *sql,
+												HTAB *crosstab_hash,
+												TupleDesc tupdesc,
+												bool randomAccess);
+static void validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch, bool show_serial);
+static bool compatCrosstabTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
+static void compatConnectbyTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
+static void get_normal_pair(float8 *x1, float8 *x2);
+static Tuplestorestate *connectby(char *relname,
+								  char *key_fld,
+								  char *parent_key_fld,
+								  char *orderby_fld,
+								  char *branch_delim,
+								  char *start_with,
+								  int max_depth,
+								  bool show_branch,
+								  bool show_serial,
+								  MemoryContext per_query_ctx,
+								  bool randomAccess,
+								  AttInMetadata *attinmeta);
+static void build_tuplestore_recursively(char *key_fld,
+										 char *parent_key_fld,
+										 char *relname,
+										 char *orderby_fld,
+										 char *branch_delim,
+										 char *start_with,
+										 char *branch,
+										 int level,
+										 int *serial,
+										 int max_depth,
+										 bool show_branch,
+										 bool show_serial,
+										 MemoryContext per_query_ctx,
+										 AttInMetadata *attinmeta,
+										 Tuplestorestate *tupstore);
+
+typedef struct
+{
+	float8		mean;			/* mean of the distribution */
+	float8		stddev;			/* stddev of the distribution */
+	float8		carry_val;		/* hold second generated value */
+	bool		use_carry;		/* use second generated value */
+} normal_rand_fctx;
+
+#define xpfree(var_) \
+	do { \
+		if (var_ != NULL) \
+		{ \
+			pfree(var_); \
+			var_ = NULL; \
+		} \
+	} while (0)
+
+#define xpstrdup(tgtvar_, srcvar_) \
+	do { \
+		if (srcvar_) \
+			tgtvar_ = pstrdup(srcvar_); \
+		else \
+			tgtvar_ = NULL; \
+	} while (0)
+
+#define xstreq(tgtvar_, srcvar_) \
+	(((tgtvar_ == NULL) && (srcvar_ == NULL)) || \
+	 ((tgtvar_ != NULL) && (srcvar_ != NULL) && (strcmp(tgtvar_, srcvar_) == 0)))
+
+/* sign, 10 digits, '\0' */
+#define INT32_STRLEN	12
+
+/* stored info for a crosstab category */
+typedef struct crosstab_cat_desc
+{
+	char	   *catname;		/* full category name */
+	uint64		attidx;			/* zero based */
+} crosstab_cat_desc;
+
+#define MAX_CATNAME_LEN			NAMEDATALEN
+#define INIT_CATS				64
+
+#define crosstab_HashTableLookup(HASHTAB, CATNAME, CATDESC) \
+do { \
+	crosstab_HashEnt *hentry; char key[MAX_CATNAME_LEN]; \
+	\
+	MemSet(key, 0, MAX_CATNAME_LEN); \
+	snprintf(key, MAX_CATNAME_LEN - 1, "%s", CATNAME); \
+	hentry = (crosstab_HashEnt*) hash_search(HASHTAB, \
+										 key, HASH_FIND, NULL); \
+	if (hentry) \
+		CATDESC = hentry->catdesc; \
+	else \
+		CATDESC = NULL; \
+} while(0)
+
+#define crosstab_HashTableInsert(HASHTAB, CATDESC) \
+do { \
+	crosstab_HashEnt *hentry; bool found; char key[MAX_CATNAME_LEN]; \
+	\
+	MemSet(key, 0, MAX_CATNAME_LEN); \
+	snprintf(key, MAX_CATNAME_LEN - 1, "%s", CATDESC->catname); \
+	hentry = (crosstab_HashEnt*) hash_search(HASHTAB, \
+										 key, HASH_ENTER, &found); \
+	if (found) \
+		ereport(ERROR, \
+				(errcode(ERRCODE_DUPLICATE_OBJECT), \
+				 errmsg("duplicate category name"))); \
+	hentry->catdesc = CATDESC; \
+} while(0)
+
+/* hash table */
+typedef struct crosstab_hashent
+{
+	char		internal_catname[MAX_CATNAME_LEN];
+	crosstab_cat_desc *catdesc;
+} crosstab_HashEnt;
+
+/*
+ * normal_rand - return requested number of random values
+ * with a Gaussian (Normal) distribution.
+ *
+ * inputs are int numvals, float8 mean, and float8 stddev
+ * returns setof float8
+ */
+PG_FUNCTION_INFO_V1(normal_rand);
+Datum
+normal_rand(PG_FUNCTION_ARGS)
+{
+	FuncCallContext *funcctx;
+	uint64		call_cntr;
+	uint64		max_calls;
+	normal_rand_fctx *fctx;
+	float8		mean;
+	float8		stddev;
+	float8		carry_val;
+	bool		use_carry;
+	MemoryContext oldcontext;
+
+	/* stuff done only on the first call of the function */
+	if (SRF_IS_FIRSTCALL())
+	{
+		int32		num_tuples;
+
+		/* create a function context for cross-call persistence */
+		funcctx = SRF_FIRSTCALL_INIT();
+
+		/*
+		 * switch to memory context appropriate for multiple function calls
+		 */
+		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+		/* total number of tuples to be returned */
+		num_tuples = PG_GETARG_INT32(0);
+		if (num_tuples < 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("number of rows cannot be negative")));
+		funcctx->max_calls = num_tuples;
+
+		/* allocate memory for user context */
+		fctx = (normal_rand_fctx *) palloc(sizeof(normal_rand_fctx));
+
+		/*
+		 * Use fctx to keep track of upper and lower bounds from call to call.
+		 * It will also be used to carry over the spare value we get from the
+		 * Box-Muller algorithm so that we only actually calculate a new value
+		 * every other call.
+		 */
+		fctx->mean = PG_GETARG_FLOAT8(1);
+		fctx->stddev = PG_GETARG_FLOAT8(2);
+		fctx->carry_val = 0;
+		fctx->use_carry = false;
+
+		funcctx->user_fctx = fctx;
+
+		MemoryContextSwitchTo(oldcontext);
+	}
+
+	/* stuff done on every call of the function */
+	funcctx = SRF_PERCALL_SETUP();
+
+	call_cntr = funcctx->call_cntr;
+	max_calls = funcctx->max_calls;
+	fctx = funcctx->user_fctx;
+	mean = fctx->mean;
+	stddev = fctx->stddev;
+	carry_val = fctx->carry_val;
+	use_carry = fctx->use_carry;
+
+	if (call_cntr < max_calls)	/* do when there is more left to send */
+	{
+		float8		result;
+
+		if (use_carry)
+		{
+			/*
+			 * reset use_carry and use second value obtained on last pass
+			 */
+			fctx->use_carry = false;
+			result = carry_val;
+		}
+		else
+		{
+			float8		normval_1;
+			float8		normval_2;
+
+			/* Get the next two normal values */
+			get_normal_pair(&normval_1, &normval_2);
+
+			/* use the first */
+			result = mean + (stddev * normval_1);
+
+			/* and save the second */
+			fctx->carry_val = mean + (stddev * normval_2);
+			fctx->use_carry = true;
+		}
+
+		/* send the result */
+		SRF_RETURN_NEXT(funcctx, Float8GetDatum(result));
+	}
+	else
+		/* do when there is no more left */
+		SRF_RETURN_DONE(funcctx);
+}
+
+/*
+ * get_normal_pair()
+ * Assigns normally distributed (Gaussian) values to a pair of provided
+ * parameters, with mean 0, standard deviation 1.
+ *
+ * This routine implements Algorithm P (Polar method for normal deviates)
+ * from Knuth's _The_Art_of_Computer_Programming_, Volume 2, 3rd ed., pages
+ * 122-126. Knuth cites his source as "The polar method", G. E. P. Box, M. E.
+ * Muller, and G. Marsaglia, _Annals_Math,_Stat._ 29 (1958), 610-611.
+ *
+ */
+static void
+get_normal_pair(float8 *x1, float8 *x2)
+{
+	float8		u1,
+				u2,
+				v1,
+				v2,
+				s;
+
+	do
+	{
+		u1 = (float8) random() / (float8) MAX_RANDOM_VALUE;
+		u2 = (float8) random() / (float8) MAX_RANDOM_VALUE;
+
+		v1 = (2.0 * u1) - 1.0;
+		v2 = (2.0 * u2) - 1.0;
+
+		s = v1 * v1 + v2 * v2;
+	} while (s >= 1.0);
+
+	if (s == 0)
+	{
+		*x1 = 0;
+		*x2 = 0;
+	}
+	else
+	{
+		s = sqrt((-2.0 * log(s)) / s);
+		*x1 = v1 * s;
+		*x2 = v2 * s;
+	}
+}
+
+/*
+ * crosstab - create a crosstab of rowids and values columns from a
+ * SQL statement returning one rowid column, one category column,
+ * and one value column.
+ *
+ * e.g. given sql which produces:
+ *
+ *			rowid	cat		value
+ *			------+-------+-------
+ *			row1	cat1	val1
+ *			row1	cat2	val2
+ *			row1	cat3	val3
+ *			row1	cat4	val4
+ *			row2	cat1	val5
+ *			row2	cat2	val6
+ *			row2	cat3	val7
+ *			row2	cat4	val8
+ *
+ * crosstab returns:
+ *					<===== values columns =====>
+ *			rowid	cat1	cat2	cat3	cat4
+ *			------+-------+-------+-------+-------
+ *			row1	val1	val2	val3	val4
+ *			row2	val5	val6	val7	val8
+ *
+ * NOTES:
+ * 1. SQL result must be ordered by 1,2.
+ * 2. The number of values columns depends on the tuple description
+ *	  of the function's declared return type.  The return type's columns
+ *	  must match the datatypes of the SQL query's result.  The datatype
+ *	  of the category column can be anything, however.
+ * 3. Missing values (i.e. not enough adjacent rows of same rowid to
+ *	  fill the number of result values columns) are filled in with nulls.
+ * 4. Extra values (i.e. too many adjacent rows of same rowid to fill
+ *	  the number of result values columns) are skipped.
+ * 5. Rows with all nulls in the values columns are skipped.
+ */
+PG_FUNCTION_INFO_V1(crosstab);
+Datum
+crosstab(PG_FUNCTION_ARGS)
+{
+	char	   *sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
+	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+	Tuplestorestate *tupstore;
+	TupleDesc	tupdesc;
+	uint64		call_cntr;
+	uint64		max_calls;
+	AttInMetadata *attinmeta;
+	SPITupleTable *spi_tuptable;
+	TupleDesc	spi_tupdesc;
+	bool		firstpass;
+	char	   *lastrowid;
+	int			i;
+	int			num_categories;
+	MemoryContext per_query_ctx;
+	MemoryContext oldcontext;
+	int			ret;
+	uint64		proc;
+
+	/* check to see if caller supports us returning a tuplestore */
+	if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("set-valued function called in context that cannot accept a set")));
+	if (!(rsinfo->allowedModes & SFRM_Materialize))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("materialize mode required, but it is not allowed in this context")));
+
+	per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
+
+	/* Connect to SPI manager */
+	if ((ret = SPI_connect()) < 0)
+		/* internal error */
+		elog(ERROR, "crosstab: SPI_connect returned %d", ret);
+
+	/* Retrieve the desired rows */
+	ret = SPI_execute(sql, true, 0);
+	proc = SPI_processed;
+
+	/* If no qualifying tuples, fall out early */
+	if (ret != SPI_OK_SELECT || proc == 0)
+	{
+		SPI_finish();
+		rsinfo->isDone = ExprEndResult;
+		PG_RETURN_NULL();
+	}
+
+	spi_tuptable = SPI_tuptable;
+	spi_tupdesc = spi_tuptable->tupdesc;
+
+	/*----------
+	 * The provided SQL query must always return three columns.
+	 *
+	 * 1. rowname
+	 *	the label or identifier for each row in the final result
+	 * 2. category
+	 *	the label or identifier for each column in the final result
+	 * 3. values
+	 *	the value for each column in the final result
+	 *----------
+	 */
+	if (spi_tupdesc->natts != 3)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid source data SQL statement"),
+				 errdetail("The provided SQL must return 3 "
+						   "columns: rowid, category, and values.")));
+
+	/* get a tuple descriptor for our result type */
+	switch (get_call_result_type(fcinfo, NULL, &tupdesc))
+	{
+		case TYPEFUNC_COMPOSITE:
+			/* success */
+			break;
+		case TYPEFUNC_RECORD:
+			/* failed to determine actual type of RECORD */
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("function returning record called in context "
+							"that cannot accept type record")));
+			break;
+		default:
+			/* result type isn't composite */
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("return type must be a row type")));
+			break;
+	}
+
+	/*
+	 * Check that return tupdesc is compatible with the data we got from SPI,
+	 * at least based on number and type of attributes
+	 */
+	if (!compatCrosstabTupleDescs(tupdesc, spi_tupdesc))
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("return and sql tuple descriptions are " \
+						"incompatible")));
+
+	/*
+	 * switch to long-lived memory context
+	 */
+	oldcontext = MemoryContextSwitchTo(per_query_ctx);
+
+	/* make sure we have a persistent copy of the result tupdesc */
+	tupdesc = CreateTupleDescCopy(tupdesc);
+
+	/* initialize our tuplestore in long-lived context */
+	tupstore =
+		tuplestore_begin_heap(rsinfo->allowedModes & SFRM_Materialize_Random,
+							  false, work_mem);
+
+	MemoryContextSwitchTo(oldcontext);
+
+	/*
+	 * Generate attribute metadata needed later to produce tuples from raw C
+	 * strings
+	 */
+	attinmeta = TupleDescGetAttInMetadata(tupdesc);
+
+	/* total number of tuples to be examined */
+	max_calls = proc;
+
+	/* the return tuple always must have 1 rowid + num_categories columns */
+	num_categories = tupdesc->natts - 1;
+
+	firstpass = true;
+	lastrowid = NULL;
+
+	for (call_cntr = 0; call_cntr < max_calls; call_cntr++)
+	{
+		bool		skip_tuple = false;
+		char	  **values;
+
+		/* allocate and zero space */
+		values = (char **) palloc0((1 + num_categories) * sizeof(char *));
+
+		/*
+		 * now loop through the sql results and assign each value in sequence
+		 * to the next category
+		 */
+		for (i = 0; i < num_categories; i++)
+		{
+			HeapTuple	spi_tuple;
+			char	   *rowid;
+
+			/* see if we've gone too far already */
+			if (call_cntr >= max_calls)
+				break;
+
+			/* get the next sql result tuple */
+			spi_tuple = spi_tuptable->vals[call_cntr];
+
+			/* get the rowid from the current sql result tuple */
+			rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
+
+			/*
+			 * If this is the first pass through the values for this rowid,
+			 * set the first column to rowid
+			 */
+			if (i == 0)
+			{
+				xpstrdup(values[0], rowid);
+
+				/*
+				 * Check to see if the rowid is the same as that of the last
+				 * tuple sent -- if so, skip this tuple entirely
+				 */
+				if (!firstpass && xstreq(lastrowid, rowid))
+				{
+					xpfree(rowid);
+					skip_tuple = true;
+					break;
+				}
+			}
+
+			/*
+			 * If rowid hasn't changed on us, continue building the output
+			 * tuple.
+			 */
+			if (xstreq(rowid, values[0]))
+			{
+				/*
+				 * Get the next category item value, which is always attribute
+				 * number three.
+				 *
+				 * Be careful to assign the value to the array index based on
+				 * which category we are presently processing.
+				 */
+				values[1 + i] = SPI_getvalue(spi_tuple, spi_tupdesc, 3);
+
+				/*
+				 * increment the counter since we consume a row for each
+				 * category, but not for last pass because the outer loop will
+				 * do that for us
+				 */
+				if (i < (num_categories - 1))
+					call_cntr++;
+				xpfree(rowid);
+			}
+			else
+			{
+				/*
+				 * We'll fill in NULLs for the missing values, but we need to
+				 * decrement the counter since this sql result row doesn't
+				 * belong to the current output tuple.
+				 */
+				call_cntr--;
+				xpfree(rowid);
+				break;
+			}
+		}
+
+		if (!skip_tuple)
+		{
+			HeapTuple	tuple;
+
+			/* build the tuple and store it */
+			tuple = BuildTupleFromCStrings(attinmeta, values);
+			tuplestore_puttuple(tupstore, tuple);
+			heap_freetuple(tuple);
+		}
+
+		/* Remember current rowid */
+		xpfree(lastrowid);
+		xpstrdup(lastrowid, values[0]);
+		firstpass = false;
+
+		/* Clean up */
+		for (i = 0; i < num_categories + 1; i++)
+			if (values[i] != NULL)
+				pfree(values[i]);
+		pfree(values);
+	}
+
+	/* let the caller know we're sending back a tuplestore */
+	rsinfo->returnMode = SFRM_Materialize;
+	rsinfo->setResult = tupstore;
+	rsinfo->setDesc = tupdesc;
+
+	/* release SPI related resources (and return to caller's context) */
+	SPI_finish();
+
+	return (Datum) 0;
+}
+
+/*
+ * crosstab_hash - reimplement crosstab as materialized function and
+ * properly deal with missing values (i.e. don't pack remaining
+ * values to the left)
+ *
+ * crosstab - create a crosstab of rowids and values columns from a
+ * SQL statement returning one rowid column, one category column,
+ * and one value column.
+ *
+ * e.g. given sql which produces:
+ *
+ *			rowid	cat		value
+ *			------+-------+-------
+ *			row1	cat1	val1
+ *			row1	cat2	val2
+ *			row1	cat4	val4
+ *			row2	cat1	val5
+ *			row2	cat2	val6
+ *			row2	cat3	val7
+ *			row2	cat4	val8
+ *
+ * crosstab returns:
+ *					<===== values columns =====>
+ *			rowid	cat1	cat2	cat3	cat4
+ *			------+-------+-------+-------+-------
+ *			row1	val1	val2	null	val4
+ *			row2	val5	val6	val7	val8
+ *
+ * NOTES:
+ * 1. SQL result must be ordered by 1.
+ * 2. The number of values columns depends on the tuple description
+ *	  of the function's declared return type.
+ * 3. Missing values (i.e. missing category) are filled in with nulls.
+ * 4. Extra values (i.e. not in category results) are skipped.
+ */
+PG_FUNCTION_INFO_V1(crosstab_hash);
+Datum
+crosstab_hash(PG_FUNCTION_ARGS)
+{
+	char	   *sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
+	char	   *cats_sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
+	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+	TupleDesc	tupdesc;
+	MemoryContext per_query_ctx;
+	MemoryContext oldcontext;
+	HTAB	   *crosstab_hash;
+
+	/* check to see if caller supports us returning a tuplestore */
+	if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("set-valued function called in context that cannot accept a set")));
+	if (!(rsinfo->allowedModes & SFRM_Materialize) ||
+		rsinfo->expectedDesc == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("materialize mode required, but it is not allowed in this context")));
+
+	per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
+	oldcontext = MemoryContextSwitchTo(per_query_ctx);
+
+	/* get the requested return tuple description */
+	tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
+
+	/*
+	 * Check to make sure we have a reasonable tuple descriptor
+	 *
+	 * Note we will attempt to coerce the values into whatever the return
+	 * attribute type is and depend on the "in" function to complain if
+	 * needed.
+	 */
+	if (tupdesc->natts < 2)
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("query-specified return tuple and " \
+						"crosstab function are not compatible")));
+
+	/* load up the categories hash table */
+	crosstab_hash = load_categories_hash(cats_sql, per_query_ctx);
+
+	/* let the caller know we're sending back a tuplestore */
+	rsinfo->returnMode = SFRM_Materialize;
+
+	/* now go build it */
+	rsinfo->setResult = get_crosstab_tuplestore(sql,
+												crosstab_hash,
+												tupdesc,
+												rsinfo->allowedModes & SFRM_Materialize_Random);
+
+	/*
+	 * SFRM_Materialize mode expects us to return a NULL Datum. The actual
+	 * tuples are in our tuplestore and passed back through rsinfo->setResult.
+	 * rsinfo->setDesc is set to the tuple description that we actually used
+	 * to build our tuples with, so the caller can verify we did what it was
+	 * expecting.
+	 */
+	rsinfo->setDesc = tupdesc;
+	MemoryContextSwitchTo(oldcontext);
+
+	return (Datum) 0;
+}
+
+/*
+ * load up the categories hash table
+ */
+static HTAB *
+load_categories_hash(char *cats_sql, MemoryContext per_query_ctx)
+{
+	HTAB	   *crosstab_hash;
+	HASHCTL		ctl;
+	int			ret;
+	uint64		proc;
+	MemoryContext SPIcontext;
+
+	/* initialize the category hash table */
+	ctl.keysize = MAX_CATNAME_LEN;
+	ctl.entrysize = sizeof(crosstab_HashEnt);
+	ctl.hcxt = per_query_ctx;
+
+	/*
+	 * use INIT_CATS, defined above as a guess of how many hash table entries
+	 * to create, initially
+	 */
+	crosstab_hash = hash_create("crosstab hash",
+								INIT_CATS,
+								&ctl,
+								HASH_ELEM | HASH_STRINGS | HASH_CONTEXT);
+
+	/* Connect to SPI manager */
+	if ((ret = SPI_connect()) < 0)
+		/* internal error */
+		elog(ERROR, "load_categories_hash: SPI_connect returned %d", ret);
+
+	/* Retrieve the category name rows */
+	ret = SPI_execute(cats_sql, true, 0);
+	proc = SPI_processed;
+
+	/* Check for qualifying tuples */
+	if ((ret == SPI_OK_SELECT) && (proc > 0))
+	{
+		SPITupleTable *spi_tuptable = SPI_tuptable;
+		TupleDesc	spi_tupdesc = spi_tuptable->tupdesc;
+		uint64		i;
+
+		/*
+		 * The provided categories SQL query must always return one column:
+		 * category - the label or identifier for each column
+		 */
+		if (spi_tupdesc->natts != 1)
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 errmsg("provided \"categories\" SQL must " \
+							"return 1 column of at least one row")));
+
+		for (i = 0; i < proc; i++)
+		{
+			crosstab_cat_desc *catdesc;
+			char	   *catname;
+			HeapTuple	spi_tuple;
+
+			/* get the next sql result tuple */
+			spi_tuple = spi_tuptable->vals[i];
+
+			/* get the category from the current sql result tuple */
+			catname = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
+			if (catname == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("provided \"categories\" SQL must " \
+								"not return NULL values")));
+
+			SPIcontext = MemoryContextSwitchTo(per_query_ctx);
+
+			catdesc = (crosstab_cat_desc *) palloc(sizeof(crosstab_cat_desc));
+			catdesc->catname = catname;
+			catdesc->attidx = i;
+
+			/* Add the proc description block to the hashtable */
+			crosstab_HashTableInsert(crosstab_hash, catdesc);
+
+			MemoryContextSwitchTo(SPIcontext);
+		}
+	}
+
+	if (SPI_finish() != SPI_OK_FINISH)
+		/* internal error */
+		elog(ERROR, "load_categories_hash: SPI_finish() failed");
+
+	return crosstab_hash;
+}
+
+/*
+ * create and populate the crosstab tuplestore using the provided source query
+ */
+static Tuplestorestate *
+get_crosstab_tuplestore(char *sql,
+						HTAB *crosstab_hash,
+						TupleDesc tupdesc,
+						bool randomAccess)
+{
+	Tuplestorestate *tupstore;
+	int			num_categories = hash_get_num_entries(crosstab_hash);
+	AttInMetadata *attinmeta = TupleDescGetAttInMetadata(tupdesc);
+	char	  **values;
+	HeapTuple	tuple;
+	int			ret;
+	uint64		proc;
+
+	/* initialize our tuplestore (while still in query context!) */
+	tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
+
+	/* Connect to SPI manager */
+	if ((ret = SPI_connect()) < 0)
+		/* internal error */
+		elog(ERROR, "get_crosstab_tuplestore: SPI_connect returned %d", ret);
+
+	/* Now retrieve the crosstab source rows */
+	ret = SPI_execute(sql, true, 0);
+	proc = SPI_processed;
+
+	/* Check for qualifying tuples */
+	if ((ret == SPI_OK_SELECT) && (proc > 0))
+	{
+		SPITupleTable *spi_tuptable = SPI_tuptable;
+		TupleDesc	spi_tupdesc = spi_tuptable->tupdesc;
+		int			ncols = spi_tupdesc->natts;
+		char	   *rowid;
+		char	   *lastrowid = NULL;
+		bool		firstpass = true;
+		uint64		i;
+		int			j;
+		int			result_ncols;
+
+		if (num_categories == 0)
+		{
+			/* no qualifying category tuples */
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 errmsg("provided \"categories\" SQL must " \
+							"return 1 column of at least one row")));
+		}
+
+		/*
+		 * The provided SQL query must always return at least three columns:
+		 *
+		 * 1. rowname	the label for each row - column 1 in the final result
+		 * 2. category	the label for each value-column in the final result 3.
+		 * value	 the values used to populate the value-columns
+		 *
+		 * If there are more than three columns, the last two are taken as
+		 * "category" and "values". The first column is taken as "rowname".
+		 * Additional columns (2 thru N-2) are assumed the same for the same
+		 * "rowname", and are copied into the result tuple from the first time
+		 * we encounter a particular rowname.
+		 */
+		if (ncols < 3)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("invalid source data SQL statement"),
+					 errdetail("The provided SQL must return 3 " \
+							   " columns; rowid, category, and values.")));
+
+		result_ncols = (ncols - 2) + num_categories;
+
+		/* Recheck to make sure we tuple descriptor still looks reasonable */
+		if (tupdesc->natts != result_ncols)
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 errmsg("invalid return type"),
+					 errdetail("Query-specified return " \
+							   "tuple has %d columns but crosstab " \
+							   "returns %d.", tupdesc->natts, result_ncols)));
+
+		/* allocate space and make sure it's clear */
+		values = (char **) palloc0(result_ncols * sizeof(char *));
+
+		for (i = 0; i < proc; i++)
+		{
+			HeapTuple	spi_tuple;
+			crosstab_cat_desc *catdesc;
+			char	   *catname;
+
+			/* get the next sql result tuple */
+			spi_tuple = spi_tuptable->vals[i];
+
+			/* get the rowid from the current sql result tuple */
+			rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
+
+			/*
+			 * if we're on a new output row, grab the column values up to
+			 * column N-2 now
+			 */
+			if (firstpass || !xstreq(lastrowid, rowid))
+			{
+				/*
+				 * a new row means we need to flush the old one first, unless
+				 * we're on the very first row
+				 */
+				if (!firstpass)
+				{
+					/* rowid changed, flush the previous output row */
+					tuple = BuildTupleFromCStrings(attinmeta, values);
+
+					tuplestore_puttuple(tupstore, tuple);
+
+					for (j = 0; j < result_ncols; j++)
+						xpfree(values[j]);
+				}
+
+				values[0] = rowid;
+				for (j = 1; j < ncols - 2; j++)
+					values[j] = SPI_getvalue(spi_tuple, spi_tupdesc, j + 1);
+
+				/* we're no longer on the first pass */
+				firstpass = false;
+			}
+
+			/* look up the category and fill in the appropriate column */
+			catname = SPI_getvalue(spi_tuple, spi_tupdesc, ncols - 1);
+
+			if (catname != NULL)
+			{
+				crosstab_HashTableLookup(crosstab_hash, catname, catdesc);
+
+				if (catdesc)
+					values[catdesc->attidx + ncols - 2] =
+						SPI_getvalue(spi_tuple, spi_tupdesc, ncols);
+			}
+
+			xpfree(lastrowid);
+			xpstrdup(lastrowid, rowid);
+		}
+
+		/* flush the last output row */
+		tuple = BuildTupleFromCStrings(attinmeta, values);
+
+		tuplestore_puttuple(tupstore, tuple);
+	}
+
+	if (SPI_finish() != SPI_OK_FINISH)
+		/* internal error */
+		elog(ERROR, "get_crosstab_tuplestore: SPI_finish() failed");
+
+	tuplestore_donestoring(tupstore);
+
+	return tupstore;
+}
+
+/*
+ * connectby_text - produce a result set from a hierarchical (parent/child)
+ * table.
+ *
+ * e.g. given table foo:
+ *
+ *			keyid	parent_keyid pos
+ *			------+------------+--
+ *			row1	NULL		 0
+ *			row2	row1		 0
+ *			row3	row1		 0
+ *			row4	row2		 1
+ *			row5	row2		 0
+ *			row6	row4		 0
+ *			row7	row3		 0
+ *			row8	row6		 0
+ *			row9	row5		 0
+ *
+ *
+ * connectby(text relname, text keyid_fld, text parent_keyid_fld
+ *			  [, text orderby_fld], text start_with, int max_depth
+ *			  [, text branch_delim])
+ * connectby('foo', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~') returns:
+ *
+ *		keyid	parent_id	level	 branch				serial
+ *		------+-----------+--------+-----------------------
+ *		row2	NULL		  0		  row2				  1
+ *		row5	row2		  1		  row2~row5			  2
+ *		row9	row5		  2		  row2~row5~row9	  3
+ *		row4	row2		  1		  row2~row4			  4
+ *		row6	row4		  2		  row2~row4~row6	  5
+ *		row8	row6		  3		  row2~row4~row6~row8 6
+ *
+ */
+PG_FUNCTION_INFO_V1(connectby_text);
+
+#define CONNECTBY_NCOLS					4
+#define CONNECTBY_NCOLS_NOBRANCH		3
+
+Datum
+connectby_text(PG_FUNCTION_ARGS)
+{
+	char	   *relname = text_to_cstring(PG_GETARG_TEXT_PP(0));
+	char	   *key_fld = text_to_cstring(PG_GETARG_TEXT_PP(1));
+	char	   *parent_key_fld = text_to_cstring(PG_GETARG_TEXT_PP(2));
+	char	   *start_with = text_to_cstring(PG_GETARG_TEXT_PP(3));
+	int			max_depth = PG_GETARG_INT32(4);
+	char	   *branch_delim = NULL;
+	bool		show_branch = false;
+	bool		show_serial = false;
+	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+	TupleDesc	tupdesc;
+	AttInMetadata *attinmeta;
+	MemoryContext per_query_ctx;
+	MemoryContext oldcontext;
+
+	/* check to see if caller supports us returning a tuplestore */
+	if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("set-valued function called in context that cannot accept a set")));
+	if (!(rsinfo->allowedModes & SFRM_Materialize) ||
+		rsinfo->expectedDesc == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("materialize mode required, but it is not allowed in this context")));
+
+	if (fcinfo->nargs == 6)
+	{
+		branch_delim = text_to_cstring(PG_GETARG_TEXT_PP(5));
+		show_branch = true;
+	}
+	else
+		/* default is no show, tilde for the delimiter */
+		branch_delim = pstrdup("~");
+
+	per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
+	oldcontext = MemoryContextSwitchTo(per_query_ctx);
+
+	/* get the requested return tuple description */
+	tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
+
+	/* does it meet our needs */
+	validateConnectbyTupleDesc(tupdesc, show_branch, show_serial);
+
+	/* OK, use it then */
+	attinmeta = TupleDescGetAttInMetadata(tupdesc);
+
+	/* OK, go to work */
+	rsinfo->returnMode = SFRM_Materialize;
+	rsinfo->setResult = connectby(relname,
+								  key_fld,
+								  parent_key_fld,
+								  NULL,
+								  branch_delim,
+								  start_with,
+								  max_depth,
+								  show_branch,
+								  show_serial,
+								  per_query_ctx,
+								  rsinfo->allowedModes & SFRM_Materialize_Random,
+								  attinmeta);
+	rsinfo->setDesc = tupdesc;
+
+	MemoryContextSwitchTo(oldcontext);
+
+	/*
+	 * SFRM_Materialize mode expects us to return a NULL Datum. The actual
+	 * tuples are in our tuplestore and passed back through rsinfo->setResult.
+	 * rsinfo->setDesc is set to the tuple description that we actually used
+	 * to build our tuples with, so the caller can verify we did what it was
+	 * expecting.
+	 */
+	return (Datum) 0;
+}
+
+PG_FUNCTION_INFO_V1(connectby_text_serial);
+Datum
+connectby_text_serial(PG_FUNCTION_ARGS)
+{
+	char	   *relname = text_to_cstring(PG_GETARG_TEXT_PP(0));
+	char	   *key_fld = text_to_cstring(PG_GETARG_TEXT_PP(1));
+	char	   *parent_key_fld = text_to_cstring(PG_GETARG_TEXT_PP(2));
+	char	   *orderby_fld = text_to_cstring(PG_GETARG_TEXT_PP(3));
+	char	   *start_with = text_to_cstring(PG_GETARG_TEXT_PP(4));
+	int			max_depth = PG_GETARG_INT32(5);
+	char	   *branch_delim = NULL;
+	bool		show_branch = false;
+	bool		show_serial = true;
+	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+	TupleDesc	tupdesc;
+	AttInMetadata *attinmeta;
+	MemoryContext per_query_ctx;
+	MemoryContext oldcontext;
+
+	/* check to see if caller supports us returning a tuplestore */
+	if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("set-valued function called in context that cannot accept a set")));
+	if (!(rsinfo->allowedModes & SFRM_Materialize) ||
+		rsinfo->expectedDesc == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("materialize mode required, but it is not allowed in this context")));
+
+	if (fcinfo->nargs == 7)
+	{
+		branch_delim = text_to_cstring(PG_GETARG_TEXT_PP(6));
+		show_branch = true;
+	}
+	else
+		/* default is no show, tilde for the delimiter */
+		branch_delim = pstrdup("~");
+
+	per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
+	oldcontext = MemoryContextSwitchTo(per_query_ctx);
+
+	/* get the requested return tuple description */
+	tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
+
+	/* does it meet our needs */
+	validateConnectbyTupleDesc(tupdesc, show_branch, show_serial);
+
+	/* OK, use it then */
+	attinmeta = TupleDescGetAttInMetadata(tupdesc);
+
+	/* OK, go to work */
+	rsinfo->returnMode = SFRM_Materialize;
+	rsinfo->setResult = connectby(relname,
+								  key_fld,
+								  parent_key_fld,
+								  orderby_fld,
+								  branch_delim,
+								  start_with,
+								  max_depth,
+								  show_branch,
+								  show_serial,
+								  per_query_ctx,
+								  rsinfo->allowedModes & SFRM_Materialize_Random,
+								  attinmeta);
+	rsinfo->setDesc = tupdesc;
+
+	MemoryContextSwitchTo(oldcontext);
+
+	/*
+	 * SFRM_Materialize mode expects us to return a NULL Datum. The actual
+	 * tuples are in our tuplestore and passed back through rsinfo->setResult.
+	 * rsinfo->setDesc is set to the tuple description that we actually used
+	 * to build our tuples with, so the caller can verify we did what it was
+	 * expecting.
+	 */
+	return (Datum) 0;
+}
+
+
+/*
+ * connectby - does the real work for connectby_text()
+ */
+static Tuplestorestate *
+connectby(char *relname,
+		  char *key_fld,
+		  char *parent_key_fld,
+		  char *orderby_fld,
+		  char *branch_delim,
+		  char *start_with,
+		  int max_depth,
+		  bool show_branch,
+		  bool show_serial,
+		  MemoryContext per_query_ctx,
+		  bool randomAccess,
+		  AttInMetadata *attinmeta)
+{
+	Tuplestorestate *tupstore = NULL;
+	int			ret;
+	MemoryContext oldcontext;
+
+	int			serial = 1;
+
+	/* Connect to SPI manager */
+	if ((ret = SPI_connect()) < 0)
+		/* internal error */
+		elog(ERROR, "connectby: SPI_connect returned %d", ret);
+
+	/* switch to longer term context to create the tuple store */
+	oldcontext = MemoryContextSwitchTo(per_query_ctx);
+
+	/* initialize our tuplestore */
+	tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
+
+	MemoryContextSwitchTo(oldcontext);
+
+	/* now go get the whole tree */
+	build_tuplestore_recursively(key_fld,
+								 parent_key_fld,
+								 relname,
+								 orderby_fld,
+								 branch_delim,
+								 start_with,
+								 start_with,	/* current_branch */
+								 0, /* initial level is 0 */
+								 &serial,	/* initial serial is 1 */
+								 max_depth,
+								 show_branch,
+								 show_serial,
+								 per_query_ctx,
+								 attinmeta,
+								 tupstore);
+
+	SPI_finish();
+
+	return tupstore;
+}
+
+static void
+build_tuplestore_recursively(char *key_fld,
+							 char *parent_key_fld,
+							 char *relname,
+							 char *orderby_fld,
+							 char *branch_delim,
+							 char *start_with,
+							 char *branch,
+							 int level,
+							 int *serial,
+							 int max_depth,
+							 bool show_branch,
+							 bool show_serial,
+							 MemoryContext per_query_ctx,
+							 AttInMetadata *attinmeta,
+							 Tuplestorestate *tupstore)
+{
+	TupleDesc	tupdesc = attinmeta->tupdesc;
+	int			ret;
+	uint64		proc;
+	int			serial_column;
+	StringInfoData sql;
+	char	  **values;
+	char	   *current_key;
+	char	   *current_key_parent;
+	char		current_level[INT32_STRLEN];
+	char		serial_str[INT32_STRLEN];
+	char	   *current_branch;
+	HeapTuple	tuple;
+
+	if (max_depth > 0 && level > max_depth)
+		return;
+
+	initStringInfo(&sql);
+
+	/* Build initial sql statement */
+	if (!show_serial)
+	{
+		appendStringInfo(&sql, "SELECT %s, %s FROM %s WHERE %s = %s AND %s IS NOT NULL AND %s <> %s",
+						 key_fld,
+						 parent_key_fld,
+						 relname,
+						 parent_key_fld,
+						 quote_literal_cstr(start_with),
+						 key_fld, key_fld, parent_key_fld);
+		serial_column = 0;
+	}
+	else
+	{
+		appendStringInfo(&sql, "SELECT %s, %s FROM %s WHERE %s = %s AND %s IS NOT NULL AND %s <> %s ORDER BY %s",
+						 key_fld,
+						 parent_key_fld,
+						 relname,
+						 parent_key_fld,
+						 quote_literal_cstr(start_with),
+						 key_fld, key_fld, parent_key_fld,
+						 orderby_fld);
+		serial_column = 1;
+	}
+
+	if (show_branch)
+		values = (char **) palloc((CONNECTBY_NCOLS + serial_column) * sizeof(char *));
+	else
+		values = (char **) palloc((CONNECTBY_NCOLS_NOBRANCH + serial_column) * sizeof(char *));
+
+	/* First time through, do a little setup */
+	if (level == 0)
+	{
+		/* root value is the one we initially start with */
+		values[0] = start_with;
+
+		/* root value has no parent */
+		values[1] = NULL;
+
+		/* root level is 0 */
+		sprintf(current_level, "%d", level);
+		values[2] = current_level;
+
+		/* root branch is just starting root value */
+		if (show_branch)
+			values[3] = start_with;
+
+		/* root starts the serial with 1 */
+		if (show_serial)
+		{
+			sprintf(serial_str, "%d", (*serial)++);
+			if (show_branch)
+				values[4] = serial_str;
+			else
+				values[3] = serial_str;
+		}
+
+		/* construct the tuple */
+		tuple = BuildTupleFromCStrings(attinmeta, values);
+
+		/* now store it */
+		tuplestore_puttuple(tupstore, tuple);
+
+		/* increment level */
+		level++;
+	}
+
+	/* Retrieve the desired rows */
+	ret = SPI_execute(sql.data, true, 0);
+	proc = SPI_processed;
+
+	/* Check for qualifying tuples */
+	if ((ret == SPI_OK_SELECT) && (proc > 0))
+	{
+		HeapTuple	spi_tuple;
+		SPITupleTable *tuptable = SPI_tuptable;
+		TupleDesc	spi_tupdesc = tuptable->tupdesc;
+		uint64		i;
+		StringInfoData branchstr;
+		StringInfoData chk_branchstr;
+		StringInfoData chk_current_key;
+
+		/*
+		 * Check that return tupdesc is compatible with the one we got from
+		 * the query.
+		 */
+		compatConnectbyTupleDescs(tupdesc, spi_tupdesc);
+
+		initStringInfo(&branchstr);
+		initStringInfo(&chk_branchstr);
+		initStringInfo(&chk_current_key);
+
+		for (i = 0; i < proc; i++)
+		{
+			/* initialize branch for this pass */
+			appendStringInfoString(&branchstr, branch);
+			appendStringInfo(&chk_branchstr, "%s%s%s", branch_delim, branch, branch_delim);
+
+			/* get the next sql result tuple */
+			spi_tuple = tuptable->vals[i];
+
+			/* get the current key (might be NULL) */
+			current_key = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
+
+			/* get the parent key (might be NULL) */
+			current_key_parent = SPI_getvalue(spi_tuple, spi_tupdesc, 2);
+
+			/* get the current level */
+			sprintf(current_level, "%d", level);
+
+			/* check to see if this key is also an ancestor */
+			if (current_key)
+			{
+				appendStringInfo(&chk_current_key, "%s%s%s",
+								 branch_delim, current_key, branch_delim);
+				if (strstr(chk_branchstr.data, chk_current_key.data))
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_RECURSION),
+							 errmsg("infinite recursion detected")));
+			}
+
+			/* OK, extend the branch */
+			if (current_key)
+				appendStringInfo(&branchstr, "%s%s", branch_delim, current_key);
+			current_branch = branchstr.data;
+
+			/* build a tuple */
+			values[0] = current_key;
+			values[1] = current_key_parent;
+			values[2] = current_level;
+			if (show_branch)
+				values[3] = current_branch;
+			if (show_serial)
+			{
+				sprintf(serial_str, "%d", (*serial)++);
+				if (show_branch)
+					values[4] = serial_str;
+				else
+					values[3] = serial_str;
+			}
+
+			tuple = BuildTupleFromCStrings(attinmeta, values);
+
+			/* store the tuple for later use */
+			tuplestore_puttuple(tupstore, tuple);
+
+			heap_freetuple(tuple);
+
+			/* recurse using current_key as the new start_with */
+			if (current_key)
+				build_tuplestore_recursively(key_fld,
+											 parent_key_fld,
+											 relname,
+											 orderby_fld,
+											 branch_delim,
+											 current_key,
+											 current_branch,
+											 level + 1,
+											 serial,
+											 max_depth,
+											 show_branch,
+											 show_serial,
+											 per_query_ctx,
+											 attinmeta,
+											 tupstore);
+
+			xpfree(current_key);
+			xpfree(current_key_parent);
+
+			/* reset branch for next pass */
+			resetStringInfo(&branchstr);
+			resetStringInfo(&chk_branchstr);
+			resetStringInfo(&chk_current_key);
+		}
+
+		xpfree(branchstr.data);
+		xpfree(chk_branchstr.data);
+		xpfree(chk_current_key.data);
+	}
+}
+
+/*
+ * Check expected (query runtime) tupdesc suitable for Connectby
+ */
+static void
+validateConnectbyTupleDesc(TupleDesc td, bool show_branch, bool show_serial)
+{
+	int			serial_column = 0;
+
+	if (show_serial)
+		serial_column = 1;
+
+	/* are there the correct number of columns */
+	if (show_branch)
+	{
+		if (td->natts != (CONNECTBY_NCOLS + serial_column))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("invalid return type"),
+					 errdetail("Query-specified return tuple has " \
+							   "wrong number of columns.")));
+	}
+	else
+	{
+		if (td->natts != CONNECTBY_NCOLS_NOBRANCH + serial_column)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("invalid return type"),
+					 errdetail("Query-specified return tuple has " \
+							   "wrong number of columns.")));
+	}
+
+	/* check that the types of the first two columns match */
+	if (TupleDescAttr(td, 0)->atttypid != TupleDescAttr(td, 1)->atttypid)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("invalid return type"),
+				 errdetail("First two columns must be the same type.")));
+
+	/* check that the type of the third column is INT4 */
+	if (TupleDescAttr(td, 2)->atttypid != INT4OID)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("invalid return type"),
+				 errdetail("Third column must be type %s.",
+						   format_type_be(INT4OID))));
+
+	/* check that the type of the fourth column is TEXT if applicable */
+	if (show_branch && TupleDescAttr(td, 3)->atttypid != TEXTOID)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("invalid return type"),
+				 errdetail("Fourth column must be type %s.",
+						   format_type_be(TEXTOID))));
+
+	/* check that the type of the fifth column is INT4 */
+	if (show_branch && show_serial &&
+		TupleDescAttr(td, 4)->atttypid != INT4OID)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("query-specified return tuple not valid for Connectby: "
+						"fifth column must be type %s",
+						format_type_be(INT4OID))));
+
+	/* check that the type of the fifth column is INT4 */
+	if (!show_branch && show_serial &&
+		TupleDescAttr(td, 3)->atttypid != INT4OID)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("query-specified return tuple not valid for Connectby: "
+						"fourth column must be type %s",
+						format_type_be(INT4OID))));
+
+	/* OK, the tupdesc is valid for our purposes */
+}
+
+/*
+ * Check if spi sql tupdesc and return tupdesc are compatible
+ */
+static void
+compatConnectbyTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc)
+{
+	Oid			ret_atttypid;
+	Oid			sql_atttypid;
+	int32		ret_atttypmod;
+	int32		sql_atttypmod;
+
+	/*
+	 * Result must have at least 2 columns.
+	 */
+	if (sql_tupdesc->natts < 2)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("invalid return type"),
+				 errdetail("Query must return at least two columns.")));
+
+	/*
+	 * These columns must match the result type indicated by the calling
+	 * query.
+	 */
+	ret_atttypid = TupleDescAttr(ret_tupdesc, 0)->atttypid;
+	sql_atttypid = TupleDescAttr(sql_tupdesc, 0)->atttypid;
+	ret_atttypmod = TupleDescAttr(ret_tupdesc, 0)->atttypmod;
+	sql_atttypmod = TupleDescAttr(sql_tupdesc, 0)->atttypmod;
+	if (ret_atttypid != sql_atttypid ||
+		(ret_atttypmod >= 0 && ret_atttypmod != sql_atttypmod))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("invalid return type"),
+				 errdetail("SQL key field type %s does " \
+						   "not match return key field type %s.",
+						   format_type_with_typemod(ret_atttypid, ret_atttypmod),
+						   format_type_with_typemod(sql_atttypid, sql_atttypmod))));
+
+	ret_atttypid = TupleDescAttr(ret_tupdesc, 1)->atttypid;
+	sql_atttypid = TupleDescAttr(sql_tupdesc, 1)->atttypid;
+	ret_atttypmod = TupleDescAttr(ret_tupdesc, 1)->atttypmod;
+	sql_atttypmod = TupleDescAttr(sql_tupdesc, 1)->atttypmod;
+	if (ret_atttypid != sql_atttypid ||
+		(ret_atttypmod >= 0 && ret_atttypmod != sql_atttypmod))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("invalid return type"),
+				 errdetail("SQL parent key field type %s does " \
+						   "not match return parent key field type %s.",
+						   format_type_with_typemod(ret_atttypid, ret_atttypmod),
+						   format_type_with_typemod(sql_atttypid, sql_atttypmod))));
+
+	/* OK, the two tupdescs are compatible for our purposes */
+}
+
+/*
+ * Check if two tupdescs match in type of attributes
+ */
+static bool
+compatCrosstabTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc)
+{
+	int			i;
+	Form_pg_attribute ret_attr;
+	Oid			ret_atttypid;
+	Form_pg_attribute sql_attr;
+	Oid			sql_atttypid;
+
+	if (ret_tupdesc->natts < 2 ||
+		sql_tupdesc->natts < 3)
+		return false;
+
+	/* check the rowid types match */
+	ret_atttypid = TupleDescAttr(ret_tupdesc, 0)->atttypid;
+	sql_atttypid = TupleDescAttr(sql_tupdesc, 0)->atttypid;
+	if (ret_atttypid != sql_atttypid)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("invalid return type"),
+				 errdetail("SQL rowid datatype does not match " \
+						   "return rowid datatype.")));
+
+	/*
+	 * - attribute [1] of the sql tuple is the category; no need to check it -
+	 * attribute [2] of the sql tuple should match attributes [1] to [natts]
+	 * of the return tuple
+	 */
+	sql_attr = TupleDescAttr(sql_tupdesc, 2);
+	for (i = 1; i < ret_tupdesc->natts; i++)
+	{
+		ret_attr = TupleDescAttr(ret_tupdesc, i);
+
+		if (ret_attr->atttypid != sql_attr->atttypid)
+			return false;
+	}
+
+	/* OK, the two tupdescs are compatible for our purposes */
+	return true;
+}
diff --git a/contrib/tablefunc/tablefunc.control b/contrib/tablefunc/tablefunc.control
new file mode 100644
index 0000000..7b25d16
--- /dev/null
+++ b/contrib/tablefunc/tablefunc.control
@@ -0,0 +1,6 @@
+# tablefunc extension
+comment = 'functions that manipulate whole tables, including crosstab'
+default_version = '1.0'
+module_pathname = '$libdir/tablefunc'
+relocatable = true
+trusted = true
diff --git a/contrib/tablefunc/tablefunc.h b/contrib/tablefunc/tablefunc.h
new file mode 100644
index 0000000..9185182
--- /dev/null
+++ b/contrib/tablefunc/tablefunc.h
@@ -0,0 +1,39 @@
+/*
+ * contrib/tablefunc/tablefunc.h
+ *
+ *
+ * tablefunc
+ *
+ * Sample to demonstrate C functions which return setof scalar
+ * and setof composite.
+ * Joe Conway <mail@joeconway.com>
+ * And contributors:
+ * Nabil Sayegh <postgresql@e-trolley.de>
+ *
+ * Copyright (c) 2002-2021, PostgreSQL Global Development Group
+ *
+ * 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.
+ *
+ */
+
+#ifndef TABLEFUNC_H
+#define TABLEFUNC_H
+
+#include "fmgr.h"
+
+#endif							/* TABLEFUNC_H */