On Sunday 09 August 2009 21:26:08 Fizu wrote: > -> Index Scan using country_ranking_user_idx on "user" > (cost=0.00..4807.25 rows=1710 width=143) (actual > time=20.923..4898.931 rows=1972 loops=1) > Index Cond: (country_id = 5)
The statistics looks good now, but almost all the time is still spent on fetching users with country_id = 5. The actual ordering is only a tiny part of the full cost. Why it takes time probably depends on your hardware in relation to database size. I guess the database doesn't fit in ram? What settings have you changed? Clustering users on country_ranking_user_idx would probably help for this specific case, but if it is a good idea depends on what other queries need to be fast. If the table or indexes are bloated then clustering on any index or doing reindex might do it. /Michael -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
