On 2013-10-09 10:02:12 -0700, Joshua D. Drake wrote: > > On 10/09/2013 07:58 AM, Bruce Momjian wrote: > > >>But it still is an independent parameter. I am just changing the default. > >> > >>>maintenance_work_mem can depend on work_mem ~ work_mem * 1 * > >>>max_connection / 4 > >> > >>That is kind of hard to do because we would have to figure out if the > >>old maintenance_work_mem was set from a default computation or by the > >>user. > > > >FYI, this auto-tuning is not for us, who understand the parameters and > >how they interact, but for the 90% of our users who would benefit from > >better defaults. It is true that there might now be cases where you > >would need to _reduce_ work_mem from its default, but I think the new > >computed default will be better for most users. > > > > Just to step in here as a consultant. Bruce is right on here. Autotuning has > nothing to do with us, it has to do with Rails developers who deploy > PostgreSQL and known nothing of it except what ActiveRecord tells them (I am > not being rude here).
But rails environments aren't exactly a good case for this. They often have a high number of connection that's even pooled. They also mostly don't have that many analytics queries where a high work_mem benefits them much. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, 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
