On 07/06/2012 02:17 PM, Yan Chunlu wrote:
so I wonder could this simple select is innocent and affected badly by other queries? how could I find those queries that really slow down the database?
It might not be other queries. Your query could be taking that long because it was blocked by a lock during maintenance work (say, an ALTER TABLE). It's also quite possible that it was held up by a slow checkpoint; check your logs to see if there are warnings about checkpoint activity.
-- Craig Ringer -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
