On 06/05/2012 07:48 AM, Andrew Jaimes wrote:
' -> Hash Join (cost=10.93..99795.09 rows=242803 width=0) (actual time=0.541..2249.027 rows=33 loops=1)' ' Hash Cond: ((a_activity.activequeueid = l_userqueue.queueid) AND (a_activity.sbuid = e_usersessions.sbuid))' ' -> Seq Scan on a_activity (cost=0.00..88462.52 rows=1208167 width=22) (actual time=0.010..1662.142
I'd be willing to bet your stats are way, way off. It expected 242,803 rows in the hash, but only got 33. In that kind of scenario, I could easily see the planner choosing a sequence scan over an index scan, as doing that many index seeks would be much more expensive than scanning the table.
What's your default_statistics_target, and when is the last time you analyzed the tables in this query?
-- Shaun Thomas OptionsHouse | 141 W. Jackson Blvd. | Suite 500 | Chicago IL, 60604 312-444-8534 sthomas@xxxxxxxxxxxxxxxx ______________________________________________ See http://www.peak6.com/email_disclaimer/ for terms and conditions related to this email -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
