diff --git a/contrib/hstore/Makefile b/contrib/hstore/Makefile
index 82908de..3000679 100644
--- a/contrib/hstore/Makefile
+++ b/contrib/hstore/Makefile
@@ -5,7 +5,8 @@ OBJS = hstore_io.o hstore_op.o hstore_gist.o hstore_gin.o hstore_compat.o \
 	$(WIN32RES)
 
 EXTENSION = hstore
-DATA = hstore--1.3.sql hstore--1.2--1.3.sql \
+DATA = hstore--1.4.sql \
+	hstore--1.3--1.4.sql hstore--1.2--1.3.sql \
 	hstore--1.1--1.2.sql hstore--1.0--1.1.sql \
 	hstore--unpackaged--1.0.sql
 PGFILEDESC = "hstore - key/value pair data type"
diff --git a/contrib/hstore/expected/hstore.out b/contrib/hstore/expected/hstore.out
index 6773a2b..dd1a13f 100644
--- a/contrib/hstore/expected/hstore.out
+++ b/contrib/hstore/expected/hstore.out
@@ -1507,3 +1507,22 @@ select json_agg(q) from (select f1, hstore_to_json_loose(f2) as f2 from test_jso
   {"f1":"rec2","f2":{"b": false, "c": "null", "d": -12345, "e": "012345.6", "f": -1.234, "g": 0.345e-4, "a key": 2}}]
 (1 row)
 
+-- length
+select hstore_length('a=>b');
+ hstore_length 
+---------------
+             1
+(1 row)
+
+select hstore_length('a=>b, b=>null');
+ hstore_length 
+---------------
+             2
+(1 row)
+
+select hstore_length('');
+ hstore_length 
+---------------
+             0
+(1 row)
+
diff --git a/contrib/hstore/hstore--1.3--1.4.sql b/contrib/hstore/hstore--1.3--1.4.sql
new file mode 100644
index 0000000..23ab9ae
--- /dev/null
+++ b/contrib/hstore/hstore--1.3--1.4.sql
@@ -0,0 +1,9 @@
+/* contrib/hstore/hstore--1.3--1.4.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION hstore UPDATE TO '1.4'" to load this file. \quit
+
+CREATE FUNCTION hstore_length(hstore)
+RETURNS integer
+AS 'MODULE_PATHNAME', 'hstore_length'
+LANGUAGE C IMMUTABLE STRICT;
diff --git a/contrib/hstore/hstore--1.3.sql b/contrib/hstore/hstore--1.3.sql
deleted file mode 100644
index b9b478d..0000000
--- a/contrib/hstore/hstore--1.3.sql
+++ /dev/null
@@ -1,550 +0,0 @@
-/* contrib/hstore/hstore--1.3.sql */
-
--- complain if script is sourced in psql, rather than via CREATE EXTENSION
-\echo Use "CREATE EXTENSION hstore" to load this file. \quit
-
-CREATE TYPE hstore;
-
-CREATE FUNCTION hstore_in(cstring)
-RETURNS hstore
-AS 'MODULE_PATHNAME'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION hstore_out(hstore)
-RETURNS cstring
-AS 'MODULE_PATHNAME'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION hstore_recv(internal)
-RETURNS hstore
-AS 'MODULE_PATHNAME'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION hstore_send(hstore)
-RETURNS bytea
-AS 'MODULE_PATHNAME'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE TYPE hstore (
-        INTERNALLENGTH = -1,
-        INPUT = hstore_in,
-        OUTPUT = hstore_out,
-        RECEIVE = hstore_recv,
-        SEND = hstore_send,
-        STORAGE = extended
-);
-
-CREATE FUNCTION hstore_version_diag(hstore)
-RETURNS integer
-AS 'MODULE_PATHNAME','hstore_version_diag'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION fetchval(hstore,text)
-RETURNS text
-AS 'MODULE_PATHNAME','hstore_fetchval'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE OPERATOR -> (
-	LEFTARG = hstore,
-	RIGHTARG = text,
-	PROCEDURE = fetchval
-);
-
-CREATE FUNCTION slice_array(hstore,text[])
-RETURNS text[]
-AS 'MODULE_PATHNAME','hstore_slice_to_array'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE OPERATOR -> (
-	LEFTARG = hstore,
-	RIGHTARG = text[],
-	PROCEDURE = slice_array
-);
-
-CREATE FUNCTION slice(hstore,text[])
-RETURNS hstore
-AS 'MODULE_PATHNAME','hstore_slice_to_hstore'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION isexists(hstore,text)
-RETURNS bool
-AS 'MODULE_PATHNAME','hstore_exists'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION exist(hstore,text)
-RETURNS bool
-AS 'MODULE_PATHNAME','hstore_exists'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE OPERATOR ? (
-	LEFTARG = hstore,
-	RIGHTARG = text,
-	PROCEDURE = exist,
-	RESTRICT = contsel,
-	JOIN = contjoinsel
-);
-
-CREATE FUNCTION exists_any(hstore,text[])
-RETURNS bool
-AS 'MODULE_PATHNAME','hstore_exists_any'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE OPERATOR ?| (
-	LEFTARG = hstore,
-	RIGHTARG = text[],
-	PROCEDURE = exists_any,
-	RESTRICT = contsel,
-	JOIN = contjoinsel
-);
-
-CREATE FUNCTION exists_all(hstore,text[])
-RETURNS bool
-AS 'MODULE_PATHNAME','hstore_exists_all'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE OPERATOR ?& (
-	LEFTARG = hstore,
-	RIGHTARG = text[],
-	PROCEDURE = exists_all,
-	RESTRICT = contsel,
-	JOIN = contjoinsel
-);
-
-CREATE FUNCTION isdefined(hstore,text)
-RETURNS bool
-AS 'MODULE_PATHNAME','hstore_defined'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION defined(hstore,text)
-RETURNS bool
-AS 'MODULE_PATHNAME','hstore_defined'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION delete(hstore,text)
-RETURNS hstore
-AS 'MODULE_PATHNAME','hstore_delete'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION delete(hstore,text[])
-RETURNS hstore
-AS 'MODULE_PATHNAME','hstore_delete_array'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION delete(hstore,hstore)
-RETURNS hstore
-AS 'MODULE_PATHNAME','hstore_delete_hstore'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE OPERATOR - (
-	LEFTARG = hstore,
-	RIGHTARG = text,
-	PROCEDURE = delete
-);
-
-CREATE OPERATOR - (
-	LEFTARG = hstore,
-	RIGHTARG = text[],
-	PROCEDURE = delete
-);
-
-CREATE OPERATOR - (
-	LEFTARG = hstore,
-	RIGHTARG = hstore,
-	PROCEDURE = delete
-);
-
-CREATE FUNCTION hs_concat(hstore,hstore)
-RETURNS hstore
-AS 'MODULE_PATHNAME','hstore_concat'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE OPERATOR || (
-	LEFTARG = hstore,
-	RIGHTARG = hstore,
-	PROCEDURE = hs_concat
-);
-
-CREATE FUNCTION hs_contains(hstore,hstore)
-RETURNS bool
-AS 'MODULE_PATHNAME','hstore_contains'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION hs_contained(hstore,hstore)
-RETURNS bool
-AS 'MODULE_PATHNAME','hstore_contained'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE OPERATOR @> (
-	LEFTARG = hstore,
-	RIGHTARG = hstore,
-	PROCEDURE = hs_contains,
-	COMMUTATOR = '<@',
-	RESTRICT = contsel,
-	JOIN = contjoinsel
-);
-
-CREATE OPERATOR <@ (
-	LEFTARG = hstore,
-	RIGHTARG = hstore,
-	PROCEDURE = hs_contained,
-	COMMUTATOR = '@>',
-	RESTRICT = contsel,
-	JOIN = contjoinsel
-);
-
--- obsolete:
-CREATE OPERATOR @ (
-	LEFTARG = hstore,
-	RIGHTARG = hstore,
-	PROCEDURE = hs_contains,
-	COMMUTATOR = '~',
-	RESTRICT = contsel,
-	JOIN = contjoinsel
-);
-
-CREATE OPERATOR ~ (
-	LEFTARG = hstore,
-	RIGHTARG = hstore,
-	PROCEDURE = hs_contained,
-	COMMUTATOR = '@',
-	RESTRICT = contsel,
-	JOIN = contjoinsel
-);
-
-CREATE FUNCTION tconvert(text,text)
-RETURNS hstore
-AS 'MODULE_PATHNAME','hstore_from_text'
-LANGUAGE C IMMUTABLE; -- not STRICT; needs to allow (key,NULL)
-
-CREATE FUNCTION hstore(text,text)
-RETURNS hstore
-AS 'MODULE_PATHNAME','hstore_from_text'
-LANGUAGE C IMMUTABLE; -- not STRICT; needs to allow (key,NULL)
-
-CREATE FUNCTION hstore(text[],text[])
-RETURNS hstore
-AS 'MODULE_PATHNAME', 'hstore_from_arrays'
-LANGUAGE C IMMUTABLE; -- not STRICT; allows (keys,null)
-
-CREATE FUNCTION hstore(text[])
-RETURNS hstore
-AS 'MODULE_PATHNAME', 'hstore_from_array'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE CAST (text[] AS hstore)
-  WITH FUNCTION hstore(text[]);
-
-CREATE FUNCTION hstore_to_json(hstore)
-RETURNS json
-AS 'MODULE_PATHNAME', 'hstore_to_json'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE CAST (hstore AS json)
-  WITH FUNCTION hstore_to_json(hstore);
-
-CREATE FUNCTION hstore_to_json_loose(hstore)
-RETURNS json
-AS 'MODULE_PATHNAME', 'hstore_to_json_loose'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE FUNCTION hstore_to_jsonb(hstore)
-RETURNS jsonb
-AS 'MODULE_PATHNAME', 'hstore_to_jsonb'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE CAST (hstore AS jsonb)
-  WITH FUNCTION hstore_to_jsonb(hstore);
-
-CREATE FUNCTION hstore_to_jsonb_loose(hstore)
-RETURNS jsonb
-AS 'MODULE_PATHNAME', 'hstore_to_jsonb_loose'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE FUNCTION hstore(record)
-RETURNS hstore
-AS 'MODULE_PATHNAME', 'hstore_from_record'
-LANGUAGE C IMMUTABLE; -- not STRICT; allows (null::recordtype)
-
-CREATE FUNCTION hstore_to_array(hstore)
-RETURNS text[]
-AS 'MODULE_PATHNAME','hstore_to_array'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE OPERATOR %% (
-       RIGHTARG = hstore,
-       PROCEDURE = hstore_to_array
-);
-
-CREATE FUNCTION hstore_to_matrix(hstore)
-RETURNS text[]
-AS 'MODULE_PATHNAME','hstore_to_matrix'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE OPERATOR %# (
-       RIGHTARG = hstore,
-       PROCEDURE = hstore_to_matrix
-);
-
-CREATE FUNCTION akeys(hstore)
-RETURNS text[]
-AS 'MODULE_PATHNAME','hstore_akeys'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION avals(hstore)
-RETURNS text[]
-AS 'MODULE_PATHNAME','hstore_avals'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION skeys(hstore)
-RETURNS setof text
-AS 'MODULE_PATHNAME','hstore_skeys'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION svals(hstore)
-RETURNS setof text
-AS 'MODULE_PATHNAME','hstore_svals'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION each(IN hs hstore,
-    OUT key text,
-    OUT value text)
-RETURNS SETOF record
-AS 'MODULE_PATHNAME','hstore_each'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION populate_record(anyelement,hstore)
-RETURNS anyelement
-AS 'MODULE_PATHNAME', 'hstore_populate_record'
-LANGUAGE C IMMUTABLE; -- not STRICT; allows (null::rectype,hstore)
-
-CREATE OPERATOR #= (
-	LEFTARG = anyelement,
-	RIGHTARG = hstore,
-	PROCEDURE = populate_record
-);
-
--- btree support
-
-CREATE FUNCTION hstore_eq(hstore,hstore)
-RETURNS boolean
-AS 'MODULE_PATHNAME','hstore_eq'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION hstore_ne(hstore,hstore)
-RETURNS boolean
-AS 'MODULE_PATHNAME','hstore_ne'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION hstore_gt(hstore,hstore)
-RETURNS boolean
-AS 'MODULE_PATHNAME','hstore_gt'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION hstore_ge(hstore,hstore)
-RETURNS boolean
-AS 'MODULE_PATHNAME','hstore_ge'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION hstore_lt(hstore,hstore)
-RETURNS boolean
-AS 'MODULE_PATHNAME','hstore_lt'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION hstore_le(hstore,hstore)
-RETURNS boolean
-AS 'MODULE_PATHNAME','hstore_le'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION hstore_cmp(hstore,hstore)
-RETURNS integer
-AS 'MODULE_PATHNAME','hstore_cmp'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE OPERATOR = (
-       LEFTARG = hstore,
-       RIGHTARG = hstore,
-       PROCEDURE = hstore_eq,
-       COMMUTATOR = =,
-       NEGATOR = <>,
-       RESTRICT = eqsel,
-       JOIN = eqjoinsel,
-       MERGES,
-       HASHES
-);
-CREATE OPERATOR <> (
-       LEFTARG = hstore,
-       RIGHTARG = hstore,
-       PROCEDURE = hstore_ne,
-       COMMUTATOR = <>,
-       NEGATOR = =,
-       RESTRICT = neqsel,
-       JOIN = neqjoinsel
-);
-
--- the comparison operators have funky names (and are undocumented)
--- in an attempt to discourage anyone from actually using them. they
--- only exist to support the btree opclass
-
-CREATE OPERATOR #<# (
-       LEFTARG = hstore,
-       RIGHTARG = hstore,
-       PROCEDURE = hstore_lt,
-       COMMUTATOR = #>#,
-       NEGATOR = #>=#,
-       RESTRICT = scalarltsel,
-       JOIN = scalarltjoinsel
-);
-CREATE OPERATOR #<=# (
-       LEFTARG = hstore,
-       RIGHTARG = hstore,
-       PROCEDURE = hstore_le,
-       COMMUTATOR = #>=#,
-       NEGATOR = #>#,
-       RESTRICT = scalarltsel,
-       JOIN = scalarltjoinsel
-);
-CREATE OPERATOR #># (
-       LEFTARG = hstore,
-       RIGHTARG = hstore,
-       PROCEDURE = hstore_gt,
-       COMMUTATOR = #<#,
-       NEGATOR = #<=#,
-       RESTRICT = scalargtsel,
-       JOIN = scalargtjoinsel
-);
-CREATE OPERATOR #>=# (
-       LEFTARG = hstore,
-       RIGHTARG = hstore,
-       PROCEDURE = hstore_ge,
-       COMMUTATOR = #<=#,
-       NEGATOR = #<#,
-       RESTRICT = scalargtsel,
-       JOIN = scalargtjoinsel
-);
-
-CREATE OPERATOR CLASS btree_hstore_ops
-DEFAULT FOR TYPE hstore USING btree
-AS
-	OPERATOR	1	#<# ,
-	OPERATOR	2	#<=# ,
-	OPERATOR	3	= ,
-	OPERATOR	4	#>=# ,
-	OPERATOR	5	#># ,
-	FUNCTION	1	hstore_cmp(hstore,hstore);
-
--- hash support
-
-CREATE FUNCTION hstore_hash(hstore)
-RETURNS integer
-AS 'MODULE_PATHNAME','hstore_hash'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE OPERATOR CLASS hash_hstore_ops
-DEFAULT FOR TYPE hstore USING hash
-AS
-	OPERATOR	1	= ,
-	FUNCTION	1	hstore_hash(hstore);
-
--- GiST support
-
-CREATE TYPE ghstore;
-
-CREATE FUNCTION ghstore_in(cstring)
-RETURNS ghstore
-AS 'MODULE_PATHNAME'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE FUNCTION ghstore_out(ghstore)
-RETURNS cstring
-AS 'MODULE_PATHNAME'
-LANGUAGE C STRICT IMMUTABLE;
-
-CREATE TYPE ghstore (
-        INTERNALLENGTH = -1,
-        INPUT = ghstore_in,
-        OUTPUT = ghstore_out
-);
-
-CREATE FUNCTION ghstore_compress(internal)
-RETURNS internal
-AS 'MODULE_PATHNAME'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE FUNCTION ghstore_decompress(internal)
-RETURNS internal
-AS 'MODULE_PATHNAME'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE FUNCTION ghstore_penalty(internal,internal,internal)
-RETURNS internal
-AS 'MODULE_PATHNAME'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE FUNCTION ghstore_picksplit(internal, internal)
-RETURNS internal
-AS 'MODULE_PATHNAME'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE FUNCTION ghstore_union(internal, internal)
-RETURNS ghstore
-AS 'MODULE_PATHNAME'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE FUNCTION ghstore_same(ghstore, ghstore, internal)
-RETURNS internal
-AS 'MODULE_PATHNAME'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE FUNCTION ghstore_consistent(internal,hstore,smallint,oid,internal)
-RETURNS bool
-AS 'MODULE_PATHNAME'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE OPERATOR CLASS gist_hstore_ops
-DEFAULT FOR TYPE hstore USING gist
-AS
-	OPERATOR        7       @> ,
-	OPERATOR        9       ?(hstore,text) ,
-	OPERATOR        10      ?|(hstore,text[]) ,
-	OPERATOR        11      ?&(hstore,text[]) ,
-        --OPERATOR        8       <@ ,
-        OPERATOR        13      @ ,
-        --OPERATOR        14      ~ ,
-        FUNCTION        1       ghstore_consistent (internal, hstore, smallint, oid, internal),
-        FUNCTION        2       ghstore_union (internal, internal),
-        FUNCTION        3       ghstore_compress (internal),
-        FUNCTION        4       ghstore_decompress (internal),
-        FUNCTION        5       ghstore_penalty (internal, internal, internal),
-        FUNCTION        6       ghstore_picksplit (internal, internal),
-        FUNCTION        7       ghstore_same (ghstore, ghstore, internal),
-        STORAGE         ghstore;
-
--- GIN support
-
-CREATE FUNCTION gin_extract_hstore(hstore, internal)
-RETURNS internal
-AS 'MODULE_PATHNAME'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE FUNCTION gin_extract_hstore_query(hstore, internal, int2, internal, internal)
-RETURNS internal
-AS 'MODULE_PATHNAME'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE FUNCTION gin_consistent_hstore(internal, int2, hstore, int4, internal, internal)
-RETURNS bool
-AS 'MODULE_PATHNAME'
-LANGUAGE C IMMUTABLE STRICT;
-
-CREATE OPERATOR CLASS gin_hstore_ops
-DEFAULT FOR TYPE hstore USING gin
-AS
-	OPERATOR        7       @>,
-	OPERATOR        9       ?(hstore,text),
-	OPERATOR        10      ?|(hstore,text[]),
-	OPERATOR        11      ?&(hstore,text[]),
-	FUNCTION        1       bttextcmp(text,text),
-	FUNCTION        2       gin_extract_hstore(hstore, internal),
-	FUNCTION        3       gin_extract_hstore_query(hstore, internal, int2, internal, internal),
-	FUNCTION        4       gin_consistent_hstore(internal, int2, hstore, int4, internal, internal),
-	STORAGE         text;
diff --git a/contrib/hstore/hstore--1.4.sql b/contrib/hstore/hstore--1.4.sql
new file mode 100644
index 0000000..8feb20f
--- /dev/null
+++ b/contrib/hstore/hstore--1.4.sql
@@ -0,0 +1,555 @@
+/* contrib/hstore/hstore--1.4.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION hstore" to load this file. \quit
+
+CREATE TYPE hstore;
+
+CREATE FUNCTION hstore_in(cstring)
+RETURNS hstore
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION hstore_out(hstore)
+RETURNS cstring
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION hstore_recv(internal)
+RETURNS hstore
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION hstore_send(hstore)
+RETURNS bytea
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE TYPE hstore (
+        INTERNALLENGTH = -1,
+        INPUT = hstore_in,
+        OUTPUT = hstore_out,
+        RECEIVE = hstore_recv,
+        SEND = hstore_send,
+        STORAGE = extended
+);
+
+CREATE FUNCTION hstore_version_diag(hstore)
+RETURNS integer
+AS 'MODULE_PATHNAME','hstore_version_diag'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION fetchval(hstore,text)
+RETURNS text
+AS 'MODULE_PATHNAME','hstore_fetchval'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OPERATOR -> (
+	LEFTARG = hstore,
+	RIGHTARG = text,
+	PROCEDURE = fetchval
+);
+
+CREATE FUNCTION slice_array(hstore,text[])
+RETURNS text[]
+AS 'MODULE_PATHNAME','hstore_slice_to_array'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OPERATOR -> (
+	LEFTARG = hstore,
+	RIGHTARG = text[],
+	PROCEDURE = slice_array
+);
+
+CREATE FUNCTION slice(hstore,text[])
+RETURNS hstore
+AS 'MODULE_PATHNAME','hstore_slice_to_hstore'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION isexists(hstore,text)
+RETURNS bool
+AS 'MODULE_PATHNAME','hstore_exists'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION exist(hstore,text)
+RETURNS bool
+AS 'MODULE_PATHNAME','hstore_exists'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OPERATOR ? (
+	LEFTARG = hstore,
+	RIGHTARG = text,
+	PROCEDURE = exist,
+	RESTRICT = contsel,
+	JOIN = contjoinsel
+);
+
+CREATE FUNCTION exists_any(hstore,text[])
+RETURNS bool
+AS 'MODULE_PATHNAME','hstore_exists_any'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OPERATOR ?| (
+	LEFTARG = hstore,
+	RIGHTARG = text[],
+	PROCEDURE = exists_any,
+	RESTRICT = contsel,
+	JOIN = contjoinsel
+);
+
+CREATE FUNCTION exists_all(hstore,text[])
+RETURNS bool
+AS 'MODULE_PATHNAME','hstore_exists_all'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OPERATOR ?& (
+	LEFTARG = hstore,
+	RIGHTARG = text[],
+	PROCEDURE = exists_all,
+	RESTRICT = contsel,
+	JOIN = contjoinsel
+);
+
+CREATE FUNCTION isdefined(hstore,text)
+RETURNS bool
+AS 'MODULE_PATHNAME','hstore_defined'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION defined(hstore,text)
+RETURNS bool
+AS 'MODULE_PATHNAME','hstore_defined'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION delete(hstore,text)
+RETURNS hstore
+AS 'MODULE_PATHNAME','hstore_delete'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION delete(hstore,text[])
+RETURNS hstore
+AS 'MODULE_PATHNAME','hstore_delete_array'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION delete(hstore,hstore)
+RETURNS hstore
+AS 'MODULE_PATHNAME','hstore_delete_hstore'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OPERATOR - (
+	LEFTARG = hstore,
+	RIGHTARG = text,
+	PROCEDURE = delete
+);
+
+CREATE OPERATOR - (
+	LEFTARG = hstore,
+	RIGHTARG = text[],
+	PROCEDURE = delete
+);
+
+CREATE OPERATOR - (
+	LEFTARG = hstore,
+	RIGHTARG = hstore,
+	PROCEDURE = delete
+);
+
+CREATE FUNCTION hs_concat(hstore,hstore)
+RETURNS hstore
+AS 'MODULE_PATHNAME','hstore_concat'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OPERATOR || (
+	LEFTARG = hstore,
+	RIGHTARG = hstore,
+	PROCEDURE = hs_concat
+);
+
+CREATE FUNCTION hs_contains(hstore,hstore)
+RETURNS bool
+AS 'MODULE_PATHNAME','hstore_contains'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION hs_contained(hstore,hstore)
+RETURNS bool
+AS 'MODULE_PATHNAME','hstore_contained'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OPERATOR @> (
+	LEFTARG = hstore,
+	RIGHTARG = hstore,
+	PROCEDURE = hs_contains,
+	COMMUTATOR = '<@',
+	RESTRICT = contsel,
+	JOIN = contjoinsel
+);
+
+CREATE OPERATOR <@ (
+	LEFTARG = hstore,
+	RIGHTARG = hstore,
+	PROCEDURE = hs_contained,
+	COMMUTATOR = '@>',
+	RESTRICT = contsel,
+	JOIN = contjoinsel
+);
+
+-- obsolete:
+CREATE OPERATOR @ (
+	LEFTARG = hstore,
+	RIGHTARG = hstore,
+	PROCEDURE = hs_contains,
+	COMMUTATOR = '~',
+	RESTRICT = contsel,
+	JOIN = contjoinsel
+);
+
+CREATE OPERATOR ~ (
+	LEFTARG = hstore,
+	RIGHTARG = hstore,
+	PROCEDURE = hs_contained,
+	COMMUTATOR = '@',
+	RESTRICT = contsel,
+	JOIN = contjoinsel
+);
+
+CREATE FUNCTION tconvert(text,text)
+RETURNS hstore
+AS 'MODULE_PATHNAME','hstore_from_text'
+LANGUAGE C IMMUTABLE; -- not STRICT; needs to allow (key,NULL)
+
+CREATE FUNCTION hstore(text,text)
+RETURNS hstore
+AS 'MODULE_PATHNAME','hstore_from_text'
+LANGUAGE C IMMUTABLE; -- not STRICT; needs to allow (key,NULL)
+
+CREATE FUNCTION hstore(text[],text[])
+RETURNS hstore
+AS 'MODULE_PATHNAME', 'hstore_from_arrays'
+LANGUAGE C IMMUTABLE; -- not STRICT; allows (keys,null)
+
+CREATE FUNCTION hstore(text[])
+RETURNS hstore
+AS 'MODULE_PATHNAME', 'hstore_from_array'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE CAST (text[] AS hstore)
+  WITH FUNCTION hstore(text[]);
+
+CREATE FUNCTION hstore_to_json(hstore)
+RETURNS json
+AS 'MODULE_PATHNAME', 'hstore_to_json'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE CAST (hstore AS json)
+  WITH FUNCTION hstore_to_json(hstore);
+
+CREATE FUNCTION hstore_to_json_loose(hstore)
+RETURNS json
+AS 'MODULE_PATHNAME', 'hstore_to_json_loose'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION hstore_to_jsonb(hstore)
+RETURNS jsonb
+AS 'MODULE_PATHNAME', 'hstore_to_jsonb'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE CAST (hstore AS jsonb)
+  WITH FUNCTION hstore_to_jsonb(hstore);
+
+CREATE FUNCTION hstore_to_jsonb_loose(hstore)
+RETURNS jsonb
+AS 'MODULE_PATHNAME', 'hstore_to_jsonb_loose'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION hstore_length(hstore)
+RETURNS integer
+AS 'MODULE_PATHNAME', 'hstore_length'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION hstore(record)
+RETURNS hstore
+AS 'MODULE_PATHNAME', 'hstore_from_record'
+LANGUAGE C IMMUTABLE; -- not STRICT; allows (null::recordtype)
+
+CREATE FUNCTION hstore_to_array(hstore)
+RETURNS text[]
+AS 'MODULE_PATHNAME','hstore_to_array'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OPERATOR %% (
+       RIGHTARG = hstore,
+       PROCEDURE = hstore_to_array
+);
+
+CREATE FUNCTION hstore_to_matrix(hstore)
+RETURNS text[]
+AS 'MODULE_PATHNAME','hstore_to_matrix'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OPERATOR %# (
+       RIGHTARG = hstore,
+       PROCEDURE = hstore_to_matrix
+);
+
+CREATE FUNCTION akeys(hstore)
+RETURNS text[]
+AS 'MODULE_PATHNAME','hstore_akeys'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION avals(hstore)
+RETURNS text[]
+AS 'MODULE_PATHNAME','hstore_avals'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION skeys(hstore)
+RETURNS setof text
+AS 'MODULE_PATHNAME','hstore_skeys'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION svals(hstore)
+RETURNS setof text
+AS 'MODULE_PATHNAME','hstore_svals'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION each(IN hs hstore,
+    OUT key text,
+    OUT value text)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME','hstore_each'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION populate_record(anyelement,hstore)
+RETURNS anyelement
+AS 'MODULE_PATHNAME', 'hstore_populate_record'
+LANGUAGE C IMMUTABLE; -- not STRICT; allows (null::rectype,hstore)
+
+CREATE OPERATOR #= (
+	LEFTARG = anyelement,
+	RIGHTARG = hstore,
+	PROCEDURE = populate_record
+);
+
+-- btree support
+
+CREATE FUNCTION hstore_eq(hstore,hstore)
+RETURNS boolean
+AS 'MODULE_PATHNAME','hstore_eq'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION hstore_ne(hstore,hstore)
+RETURNS boolean
+AS 'MODULE_PATHNAME','hstore_ne'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION hstore_gt(hstore,hstore)
+RETURNS boolean
+AS 'MODULE_PATHNAME','hstore_gt'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION hstore_ge(hstore,hstore)
+RETURNS boolean
+AS 'MODULE_PATHNAME','hstore_ge'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION hstore_lt(hstore,hstore)
+RETURNS boolean
+AS 'MODULE_PATHNAME','hstore_lt'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION hstore_le(hstore,hstore)
+RETURNS boolean
+AS 'MODULE_PATHNAME','hstore_le'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION hstore_cmp(hstore,hstore)
+RETURNS integer
+AS 'MODULE_PATHNAME','hstore_cmp'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OPERATOR = (
+       LEFTARG = hstore,
+       RIGHTARG = hstore,
+       PROCEDURE = hstore_eq,
+       COMMUTATOR = =,
+       NEGATOR = <>,
+       RESTRICT = eqsel,
+       JOIN = eqjoinsel,
+       MERGES,
+       HASHES
+);
+CREATE OPERATOR <> (
+       LEFTARG = hstore,
+       RIGHTARG = hstore,
+       PROCEDURE = hstore_ne,
+       COMMUTATOR = <>,
+       NEGATOR = =,
+       RESTRICT = neqsel,
+       JOIN = neqjoinsel
+);
+
+-- the comparison operators have funky names (and are undocumented)
+-- in an attempt to discourage anyone from actually using them. they
+-- only exist to support the btree opclass
+
+CREATE OPERATOR #<# (
+       LEFTARG = hstore,
+       RIGHTARG = hstore,
+       PROCEDURE = hstore_lt,
+       COMMUTATOR = #>#,
+       NEGATOR = #>=#,
+       RESTRICT = scalarltsel,
+       JOIN = scalarltjoinsel
+);
+CREATE OPERATOR #<=# (
+       LEFTARG = hstore,
+       RIGHTARG = hstore,
+       PROCEDURE = hstore_le,
+       COMMUTATOR = #>=#,
+       NEGATOR = #>#,
+       RESTRICT = scalarltsel,
+       JOIN = scalarltjoinsel
+);
+CREATE OPERATOR #># (
+       LEFTARG = hstore,
+       RIGHTARG = hstore,
+       PROCEDURE = hstore_gt,
+       COMMUTATOR = #<#,
+       NEGATOR = #<=#,
+       RESTRICT = scalargtsel,
+       JOIN = scalargtjoinsel
+);
+CREATE OPERATOR #>=# (
+       LEFTARG = hstore,
+       RIGHTARG = hstore,
+       PROCEDURE = hstore_ge,
+       COMMUTATOR = #<=#,
+       NEGATOR = #<#,
+       RESTRICT = scalargtsel,
+       JOIN = scalargtjoinsel
+);
+
+CREATE OPERATOR CLASS btree_hstore_ops
+DEFAULT FOR TYPE hstore USING btree
+AS
+	OPERATOR	1	#<# ,
+	OPERATOR	2	#<=# ,
+	OPERATOR	3	= ,
+	OPERATOR	4	#>=# ,
+	OPERATOR	5	#># ,
+	FUNCTION	1	hstore_cmp(hstore,hstore);
+
+-- hash support
+
+CREATE FUNCTION hstore_hash(hstore)
+RETURNS integer
+AS 'MODULE_PATHNAME','hstore_hash'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OPERATOR CLASS hash_hstore_ops
+DEFAULT FOR TYPE hstore USING hash
+AS
+	OPERATOR	1	= ,
+	FUNCTION	1	hstore_hash(hstore);
+
+-- GiST support
+
+CREATE TYPE ghstore;
+
+CREATE FUNCTION ghstore_in(cstring)
+RETURNS ghstore
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE FUNCTION ghstore_out(ghstore)
+RETURNS cstring
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE TYPE ghstore (
+        INTERNALLENGTH = -1,
+        INPUT = ghstore_in,
+        OUTPUT = ghstore_out
+);
+
+CREATE FUNCTION ghstore_compress(internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION ghstore_decompress(internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION ghstore_penalty(internal,internal,internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION ghstore_picksplit(internal, internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION ghstore_union(internal, internal)
+RETURNS ghstore
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION ghstore_same(ghstore, ghstore, internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION ghstore_consistent(internal,hstore,smallint,oid,internal)
+RETURNS bool
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE OPERATOR CLASS gist_hstore_ops
+DEFAULT FOR TYPE hstore USING gist
+AS
+	OPERATOR        7       @> ,
+	OPERATOR        9       ?(hstore,text) ,
+	OPERATOR        10      ?|(hstore,text[]) ,
+	OPERATOR        11      ?&(hstore,text[]) ,
+        --OPERATOR        8       <@ ,
+        OPERATOR        13      @ ,
+        --OPERATOR        14      ~ ,
+        FUNCTION        1       ghstore_consistent (internal, hstore, smallint, oid, internal),
+        FUNCTION        2       ghstore_union (internal, internal),
+        FUNCTION        3       ghstore_compress (internal),
+        FUNCTION        4       ghstore_decompress (internal),
+        FUNCTION        5       ghstore_penalty (internal, internal, internal),
+        FUNCTION        6       ghstore_picksplit (internal, internal),
+        FUNCTION        7       ghstore_same (ghstore, ghstore, internal),
+        STORAGE         ghstore;
+
+-- GIN support
+
+CREATE FUNCTION gin_extract_hstore(hstore, internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION gin_extract_hstore_query(hstore, internal, int2, internal, internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION gin_consistent_hstore(internal, int2, hstore, int4, internal, internal)
+RETURNS bool
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE OPERATOR CLASS gin_hstore_ops
+DEFAULT FOR TYPE hstore USING gin
+AS
+	OPERATOR        7       @>,
+	OPERATOR        9       ?(hstore,text),
+	OPERATOR        10      ?|(hstore,text[]),
+	OPERATOR        11      ?&(hstore,text[]),
+	FUNCTION        1       bttextcmp(text,text),
+	FUNCTION        2       gin_extract_hstore(hstore, internal),
+	FUNCTION        3       gin_extract_hstore_query(hstore, internal, int2, internal, internal),
+	FUNCTION        4       gin_consistent_hstore(internal, int2, hstore, int4, internal, internal),
+	STORAGE         text;
diff --git a/contrib/hstore/hstore.control b/contrib/hstore/hstore.control
index dcc3b68..f99a937 100644
--- a/contrib/hstore/hstore.control
+++ b/contrib/hstore/hstore.control
@@ -1,5 +1,5 @@
 # hstore extension
 comment = 'data type for storing sets of (key, value) pairs'
-default_version = '1.3'
+default_version = '1.4'
 module_pathname = '$libdir/hstore'
 relocatable = true
diff --git a/contrib/hstore/hstore_op.c b/contrib/hstore/hstore_op.c
index 1e2dc88..67742c1 100644
--- a/contrib/hstore/hstore_op.c
+++ b/contrib/hstore/hstore_op.c
@@ -1076,6 +1076,15 @@ hstore_each(PG_FUNCTION_ARGS)
 	SRF_RETURN_DONE(funcctx);
 }
 
+PG_FUNCTION_INFO_V1(hstore_length);
+Datum
+hstore_length(PG_FUNCTION_ARGS)
+{
+	HStore	   *hs = PG_GETARG_HS(0);
+	int			count = HS_COUNT(hs);
+
+	PG_RETURN_INT32(count);
+}
 
 /*
  * btree sort order for hstores isn't intended to be useful; we really only
diff --git a/contrib/hstore/sql/hstore.sql b/contrib/hstore/sql/hstore.sql
index 4851478..c1f8aed 100644
--- a/contrib/hstore/sql/hstore.sql
+++ b/contrib/hstore/sql/hstore.sql
@@ -345,3 +345,8 @@ insert into test_json_agg values ('rec1','"a key" =>1, b => t, c => null, d=> 12
        ('rec2','"a key" =>2, b => f, c => "null", d=> -12345, e => 012345.6, f=> -1.234, g=> 0.345e-4');
 select json_agg(q) from test_json_agg q;
 select json_agg(q) from (select f1, hstore_to_json_loose(f2) as f2 from test_json_agg) q;
+
+-- length
+select hstore_length('a=>b');
+select hstore_length('a=>b, b=>null');
+select hstore_length('');
diff --git a/doc/src/sgml/hstore.sgml b/doc/src/sgml/hstore.sgml
index db5d440..3671821 100644
--- a/doc/src/sgml/hstore.sgml
+++ b/doc/src/sgml/hstore.sgml
@@ -306,6 +306,14 @@ b
      </row>
 
      <row>
+      <entry><function>hstore_length(hstore)</function><indexterm><primary>hstore_length</primary></indexterm></entry>
+      <entry><type>int</type></entry>
+      <entry>get the number of elements in <type>hstore</></entry>
+      <entry><literal>hstore_length('a=&gt;1,b=&gt;2')</literal></entry>
+      <entry><literal>2</literal></entry>
+     </row>
+
+     <row>
       <entry><function>hstore_to_array(hstore)</function><indexterm><primary>hstore_to_array</primary></indexterm></entry>
       <entry><type>text[]</type></entry>
       <entry>get <type>hstore</>'s keys and values as an array of alternating