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
