"Nicholay P. Chuprynin" <[EMAIL PROTECTED]> writes: > I switched enable_seqscan to 'false', restarted server and EXPLAINed the > same query again: > ... > Now it uses index scan, but query takes MUCH more time than before (about > an hour, and it's not finished yet). > It seems very strange for me.
Indexscan over a large fraction of a table is not a win compared to a sequential scan. Random access is just too expensive. > Can someone explain what's wrong here? Nothing. The planner knew what it was doing to prefer the seqscan. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster