I firstly used 9.1. After switching to 9.2. - the problem was fixed even without index only scan. I added another column to my table so this wasn't index only, but still had better index behaviour. -- View this message in context: http://postgresql.1045698.n5.nabble.com/Index-scan-and-bitmap-index-scan-hard-to-understand-how-planner-chooses-tp5760304p5760677.html Sent from the PostgreSQL - general mailing list archive at Nabble.com. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general