we have a daily vacuumdb and analyze job, generally speaking it's done in seconds, sometimes it suddenly running more than tens of minutes with same bind variable values and huge temp space got used and at that time, explain show "Hash Anti join, Hash Right join" with seq scan two tables.
Hi James,
I think it'd be much easier to help you with investigating this issue if
you shared the actual queries, and the full EXPLAIN ANALYZE output both
with and without disabled hashjoin. Or even better, share a script that
reproduces the issue (creates tables, loads data, runs the queries).
BTW you suggested each partition has ~250k rows, but the explain plan
snippet you shared does not seem to be consistent with that - it only
shows 2500-5000 rows per partition. If you run ANALYZE on the table,
does that change the plan?
regards
--
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
