On 6/3/09 7:32 PM, Janine Sisk wrote:
I'm sorry if this is a stupid question, but... I changed default_statistics_target from the default of 10 to 100, restarted PG, and then ran "vacuumdb -z" on the database. The plan is exactly the same as before. Was I supposed to do something else? Do I need to increase it even further? This is an overloaded system to start with, so I'm being fairly conservative with what I change.
It's possible that it won't change the plan; 100 is often not enough to change the statistics.
Try changing, in a superuser session, default_statistics_target to 400 and just ANALYZing the one table, and see if that changes the plan. If so, you'll want to increase the statistics setting on the filtered columns on that table.
-- Josh Berkus PostgreSQL Experts Inc. www.pgexperts.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
