Josh Berkus wrote: > In terms of adding a new GUC in 9.5: can't we take a stab at auto-tuning > this instead of adding a new GUC? We already have a bunch of freezing > GUCs which fewer than 1% of our user base has any idea how to set.
If you have development resources to pour onto 9.5, I think it would be better spent changing multixact usage tracking so that oldestOffset is included in pg_control; also make pg_multixact truncation be WAL-logged. With those changes, the need for a lot of pretty complicated code would go away. The fact that truncation is done by both vacuum and checkpoint causes a lot of the mess we were in (and from which Robert and Thomas took us --- thanks guys!). Such a change is the first step towards auto-tuning, I think. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers