Thomas Kellerer <spam_eater@xxxxxxx> writes: > I'm playing around with 9.2 beta4 and was looking into the new Index Only Scan feature. > I was a bit surprised that a "count(*)" query does not use an index. Works for me. However, the cost estimate for that is heavily dependent on how much of the table is known all-visible. If the table is getting a lot of churn, or even just hasn't been vacuumed since it quiesced, the planner will prefer a seqscan for this --- and it will be right. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
