As mentioned above, here is my contrib/tablefunc patch. It includes

three functions which exercise the tablefunc API.

show_all_settings()
   - returns the same information as SHOW ALL, but as a query result

normal_rand(int numvals, float8 mean, float8 stddev, int seed)
   - returns a set of normally distributed float8 values
   - 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.

crosstabN(text sql)
   - returns a set of row_name plus N category value columns
   - crosstab2(), crosstab3(), and crosstab4() are defined for you,
     but you can create additional crosstab functions per directions
     in the README.

Joe Conway

contrib/tablefunc/tablefunc.sql.in

@@ -0,0 +1,46 @@
+CREATE VIEW tablefunc_config_settings AS
+  SELECT
+    ''::TEXT AS name,
+    ''::TEXT AS setting;
+
+CREATE OR REPLACE FUNCTION show_all_settings()
+  RETURNS setof tablefunc_config_settings
+  AS 'MODULE_PATHNAME','show_all_settings' LANGUAGE 'c' STABLE STRICT;
+
+CREATE OR REPLACE FUNCTION normal_rand(int4, float8, float8, int4)
+  RETURNS setof float8
+  AS 'MODULE_PATHNAME','normal_rand' LANGUAGE 'c' VOLATILE STRICT;
+
+CREATE VIEW tablefunc_crosstab_2 AS
+  SELECT
+    ''::TEXT AS row_name,
+    ''::TEXT AS category_1,
+    ''::TEXT AS category_2;
+
+CREATE VIEW tablefunc_crosstab_3 AS
+  SELECT
+    ''::TEXT AS row_name,
+    ''::TEXT AS category_1,
+    ''::TEXT AS category_2,
+    ''::TEXT AS category_3;
+
+CREATE VIEW tablefunc_crosstab_4 AS
+  SELECT
+    ''::TEXT AS row_name,
+    ''::TEXT AS category_1,
+    ''::TEXT AS category_2,
+    ''::TEXT AS category_3,
+    ''::TEXT AS category_4;
+
+CREATE OR REPLACE FUNCTION crosstab2(text)
+  RETURNS setof tablefunc_crosstab_2
+  AS 'MODULE_PATHNAME','crosstab' LANGUAGE 'c' STABLE STRICT;
+
+CREATE OR REPLACE FUNCTION crosstab3(text)
+  RETURNS setof tablefunc_crosstab_3
+  AS 'MODULE_PATHNAME','crosstab' LANGUAGE 'c' STABLE STRICT;
+
+CREATE OR REPLACE FUNCTION crosstab4(text)
+  RETURNS setof tablefunc_crosstab_4
+  AS 'MODULE_PATHNAME','crosstab' LANGUAGE 'c' STABLE STRICT;
+