Hello
Current result from xpath function isn't indexable. It cannot be
problem with possibility cast it to some base types.
CREATE OR REPLACE FUNCTION xml_list_to_int(xml[])
RETURNS int[] AS $$
SELECT ARRAY(SELECT to_number(($1[i])::text,'999999.99')::int FROM generate_series(1, array_upper($1,1))
g(i))
$$ LANGUAGE SQL IMMUTABLE;
CREATE CAST (xml[] AS int[]) WITH FUNCTION xml_list_to_int(xml[]);
-- now I can build functional index
CREATE INDEX fx ON foo USING
GIN((xpath('//id/text()',objednavka_v_xml)::int[]));
Does anybody know better solution?
Regards
Pavel Stehule
