diff -r 058bb3dc685f -r 0b59724cb3f2 cubicweb/schemas/_regproc.postgres.sql
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cubicweb/schemas/_regproc.postgres.sql	Sat Jan 16 13:48:51 2016 +0100
@@ -0,0 +1,55 @@
+/* -*- sql -*-
+
+   postgres specific registered procedures,
+   require the plpgsql language installed
+
+*/
+
+DROP FUNCTION IF EXISTS comma_join (anyarray) CASCADE;
+CREATE FUNCTION comma_join (anyarray) RETURNS text AS $$
+    SELECT array_to_string($1, ', ')
+$$ LANGUAGE SQL;;
+
+
+DROP FUNCTION IF EXISTS cw_array_append_unique (anyarray, anyelement) CASCADE;
+CREATE FUNCTION cw_array_append_unique (anyarray, anyelement) RETURNS anyarray AS $$
+    SELECT array_append($1, (SELECT $2 WHERE $2 <> ALL($1)))
+$$ LANGUAGE SQL;;
+
+DROP AGGREGATE IF EXISTS group_concat (anyelement) CASCADE;
+CREATE AGGREGATE group_concat (
+  basetype = anyelement,
+  sfunc = cw_array_append_unique,
+  stype = anyarray,
+  finalfunc = comma_join,
+  initcond = '{}'
+);;
+
+
+DROP FUNCTION IF EXISTS limit_size (fulltext text, format text, maxsize integer);
+CREATE FUNCTION limit_size (fulltext text, format text, maxsize integer) RETURNS text AS $$
+DECLARE
+    plaintext text;
+BEGIN
+    IF char_length(fulltext) < maxsize THEN
+       RETURN fulltext;
+    END IF;
+    IF format = 'text/html' OR format = 'text/xhtml' OR format = 'text/xml' THEN
+       plaintext := regexp_replace(fulltext, '<[a-zA-Z/][^>]*>', '', 'g');
+    ELSE
+       plaintext := fulltext;
+    END IF;
+    IF char_length(plaintext) < maxsize THEN
+       RETURN plaintext;
+    ELSE
+       RETURN substring(plaintext from 1 for maxsize) || '...';
+    END IF;
+END
+$$ LANGUAGE plpgsql;;
+
+DROP FUNCTION IF EXISTS text_limit_size (fulltext text, maxsize integer);
+CREATE FUNCTION text_limit_size (fulltext text, maxsize integer) RETURNS text AS $$
+BEGIN
+    RETURN limit_size(fulltext, 'text/plain', maxsize);
+END
+$$ LANGUAGE plpgsql;;