please apply attached patch to current CVS.

btree_gist now supports int2 !
Thanks Janko Richter for contribution.

contrib/btree_gist/Makefile

@@ -4,15 +4,18 @@ top_builddir = ../..
 include $(top_builddir)/src/Makefile.global
 
 MODULE_big = btree_gist
-OBJS= btree_common.o btree_int4.o btree_int8.o btree_float4.o btree_float8.o btree_ts.o
+OBJS= btree_common.o btree_int2.o btree_int4.o btree_int8.o btree_float4.o btree_float8.o btree_ts.o
 DATA_built = btree_gist.sql
 DOCS = README.btree_gist
 REGRESS = btree_gist
 
-EXTRA_CLEAN = btree_int4.c btree_int8.c btree_float4.c btree_float8.c 
+EXTRA_CLEAN = btree_int2.c btree_int4.c btree_int8.c btree_float4.c btree_float8.c 
 
 include $(top_srcdir)/contrib/contrib-global.mk
 
+btree_int2.c: btree_num.c.in
+	sed 's,__DEFINE_BTREE_TYPE_HERE__,BTREE_GIST_INT2,g;s,__BTREE_GIST_TYPE__,int16,g;s,__BTREE_GIST_TYPE2__,int2,g' < $<  > $@
+
 btree_int4.c: btree_num.c.in
 	sed 's,__DEFINE_BTREE_TYPE_HERE__,BTREE_GIST_INT4,g;s,__BTREE_GIST_TYPE__,int32,g;s,__BTREE_GIST_TYPE2__,int4,g' < $<  > $@
 

contrib/btree_gist/README.btree_gist

-This is B-Tree implementation using GiST for int4, int8, float4, float8
+This is B-Tree implementation using GiST for int2, int4, int8, float4, float8
 timestamp types.
 
 All work was done by Teodor Sigaev (teodor@stack.net) and Oleg Bartunov
@@ -6,7 +6,7 @@ All work was done by Teodor Sigaev (teodor@stack.net) and Oleg Bartunov
 for additional information.
 
 NEWS:
-     Feb 5, 2003 - btree_gist now support int8, float4, float8 !
+     Feb 5, 2003 - btree_gist now support int2, int8, float4, float8 !
                    Thank Janko Richter <jankorichter@yahoo.de> for
                    contribution.
      

contrib/btree_gist/btree_gist.sql.in

@@ -3,6 +3,23 @@ SET search_path = public;
 
 SET autocommit TO 'on';
 
+-- create type of int2 key
+CREATE FUNCTION int2key_in(cstring)
+RETURNS int2key
+AS 'MODULE_PATHNAME'
+LANGUAGE 'c' WITH (isstrict);
+
+CREATE FUNCTION int2key_out(int2key)
+RETURNS cstring
+AS 'MODULE_PATHNAME'
+LANGUAGE 'c' WITH (isstrict);
+
+CREATE TYPE int2key (
+INTERNALLENGTH = 4,
+INPUT = int2key_in,
+OUTPUT = int2key_out
+);
+
 -- create type of int4 key
 CREATE FUNCTION int4key_in(cstring)
 RETURNS int4key
@@ -75,17 +92,17 @@ OUTPUT = float8key_out
 --
 --
 --
--- int4 ops
+-- int2 ops
 --
 --
 --
 -- define the GiST support methods
-CREATE FUNCTION gint4_consistent(internal,int4,int2)
+CREATE FUNCTION gint2_consistent(internal,int2,int2)
 RETURNS bool
 AS 'MODULE_PATHNAME'
 LANGUAGE 'C';
 
-CREATE FUNCTION gint4_compress(internal)
+CREATE FUNCTION gint2_compress(internal)
 RETURNS internal
 AS 'MODULE_PATHNAME'
 LANGUAGE 'C';
@@ -95,6 +112,62 @@ RETURNS internal
 AS 'MODULE_PATHNAME'
 LANGUAGE 'C';
 
+CREATE FUNCTION gint2_penalty(internal,internal,internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE 'C' WITH (isstrict);
+
+CREATE FUNCTION gint2_picksplit(internal, internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE 'C';
+
+CREATE FUNCTION gint2_union(bytea, internal)
+RETURNS int4
+AS 'MODULE_PATHNAME'
+LANGUAGE 'C';
+
+CREATE FUNCTION gint2_same(internal, internal, internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE 'C';
+
+-- Create the operator class
+CREATE OPERATOR CLASS gist_int2_ops
+DEFAULT FOR TYPE int2 USING gist 
+AS
+	OPERATOR	1	< ,
+	OPERATOR	2	<= ,
+	OPERATOR	3	= ,
+	OPERATOR	4	>= ,
+	OPERATOR	5	> ,
+	FUNCTION	1	gint2_consistent (internal, int2, int2),
+	FUNCTION	2	gint2_union (bytea, internal),
+	FUNCTION	3	gint2_compress (internal),
+	FUNCTION	4	btree_decompress (internal),
+	FUNCTION	5	gint2_penalty (internal, internal, internal),
+	FUNCTION	6	gint2_picksplit (internal, internal),
+	FUNCTION	7	gint2_same (internal, internal, internal),
+	STORAGE		int2key;
+
+--
+--
+--
+-- int4 ops
+--
+--
+--
+-- define the GiST support methods
+CREATE FUNCTION gint4_consistent(internal,int4,int2)
+RETURNS bool
+AS 'MODULE_PATHNAME'
+LANGUAGE 'C';
+
+CREATE FUNCTION gint4_compress(internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE 'C';
+
 CREATE FUNCTION gint4_penalty(internal,internal,internal)
 RETURNS internal
 AS 'MODULE_PATHNAME'

contrib/btree_gist/btree_num.c.in

@@ -51,6 +51,9 @@ g__BTREE_GIST_TYPE2___compress(PG_FUNCTION_ARGS)
 	if (entry->leafkey)
 	{
 		__BTREE_GIST_TYPE__KEY    *r = ( __BTREE_GIST_TYPE__KEY * ) palloc(sizeof(__BTREE_GIST_TYPE__KEY));
+    #ifdef BTREE_GIST_INT2
+    	int16		leaf = DatumGetInt16(entry->key);
+    #endif
     #ifdef BTREE_GIST_INT4
     	int32		leaf = DatumGetInt32(entry->key);
     #endif
@@ -80,6 +83,9 @@ Datum
 g__BTREE_GIST_TYPE2___consistent(PG_FUNCTION_ARGS)
 {
 	GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
+  #ifdef BTREE_GIST_INT2
+  	int16		query = PG_GETARG_INT16(1);
+  #endif
   #ifdef BTREE_GIST_INT4
   	int32		query = PG_GETARG_INT32(1);
   #endif