From: kimaidou [mailto:kimai...@gmail.com] Sent: Friday, February 22, 2019 10:37 AM To: pgsql-performance@lists.postgresql.org<mailto:pgsql-performance@lists.postgresql.org> Subject: Slow query with aggregate and many LEFT JOINS
Hi all, I need to optimize the following query http://paste.debian.net/hidden/ef08f864/ I use it to create a materialized view, but I think there is room for optimization. I tried to SET join_collapse_limit TO 15; with to real difference. Explain shows that the GROUP AGGREGATE and needed sort kill the performance. Do you have any hint how to optimize this ? https://explain.depesz.com/s/6nf Regards Michaël Don’t know your hardware config, or Postgres settings, but I see external disk sort. So, try setting work_mem to ~48MB. Regards, Igor Neyman
