Hi,Indeed, this query is used in a loop: CREATE OR REPLACE FUNCTION small_distinct(IN tablename character varying, IN fieldname character varying, IN sample anyelement DEFAULT ''::character varying) RETURNS SETOF anyelement AS $BODY$ BEGIN EXECUTE 'SELECT '||fieldName||' FROM '||tableName||' ORDER BY '||fieldName ||' LIMIT 1' INTO result; WHILE result IS NOT NULL LOOP RETURN NEXT; EXECUTE 'SELECT '||fieldName||' FROM '||tableName ||' WHERE '||fieldName||' > $1 ORDER BY ' || fieldName || ' LIMIT 1' INTO result USING result; END LOOP; END; $BODY$ LANGUAGE plpgsql VOLATILE COST 100 ROWS 1000; Since we have the problem, some iteration of the query are still quick (< 1ms), but others are long (> 5s). There has been a delete on the table (about 20% of the records). Then a manual VACUUM. We have recreated the index, but it did not help. In the explain analyze output, the index scan begins at 5798.912. What can be happening before that ? Index Scan using vsn_idx on dwhinv (cost=0.00..302591122.05 rows=267473826 width=12) (actual time=5798.912..5798.912 rows=1 loops=1)(Notice the delay is not planning itself, as explain is instantaneous) Yep, we certainly would like to, but this is a distant prod box, with no access to an online upgrade source, and no planned upgrade for now :-(( Regards, Franck |