On Sun, 10 Mar 2019 at 10:20, <reg_pg_stefanz@xxxxxxxxxxxxx> wrote: > I noticed that a delete on a table with many partitions seems to be > using a lot of ram. > Is this a known behaviour or related to my setup? Yeah, It's known. There's a warning against what you're doing in https://www.postgresql.org/docs/10/ddl-partitioning.html I see that note has been changed in v11's documents, but I really don't think v11 should have changed that. The memory problem still exists with v11. The only thing that was improved on that front was with how partition pruning works, which only saves CPU, not RAM. It's down to how DELETE and UPDATE plans are generated with partitioned table or inheritance parents. The memory growth is basically quadratic with the number of partitions. It's possible we may have a solution for this by the time PostgreSQL 13 is out, but it won't be fixed for 12. However, nothing is entirely certain that far out. It's probably best to reduce the number of partitions. -- David Rowley http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
