-- make sure the prerequisite libraries are loaded LOAD 'plpython2'; SELECT NULL::ltree; CREATE FUNCTION ltree_to_plpython2(val internal) RETURNS internal LANGUAGE C STRICT IMMUTABLE AS 'MODULE_PATHNAME', 'ltree_to_plpython'; CREATE TRANSFORM FOR ltree LANGUAGE plpython2u ( FROM SQL WITH FUNCTION ltree_to_plpython2(internal) );