Adam Brusselback <adambrusselback@xxxxxxxxx> writes: > As suggested in the Postgres slack channel by lukasfittl, I disabled > hashagg on my old server, and ran the query again. That changed one piece > to a groupagg (like was used on the new server) and the performance was > similar to the 9.6.1 box. If the problem is "new server won't use hashagg", I'd wonder whether the work_mem setting is the same, or whether maybe you need to bump it up some (the planner's estimate of how big the hashtable would be might have changed a bit). regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
