Excerpts from Simon Riggs's message of jue ene 05 16:21:31 -0300 2012: > On Thu, Jan 5, 2012 at 7:12 PM, Robert Haas <robertmh...@gmail.com> wrote: > > On Thu, Jan 5, 2012 at 11:10 AM, Simon Riggs <si...@2ndquadrant.com> wrote: > >> Let's commit the change to 32. > > > > I would like to do that, but I think we need to at least figure out a > > way to provide an escape hatch for people without much shared memory. > > We could do that, perhaps, by using a formula like this: > > > > 1 CLOG buffer per 128MB of shared_buffers, with a minimum of 8 and a > > maximum of 32 > > We're talking about an extra 192KB or thereabouts and Clog buffers > will only be the size of subtrans when we've finished.
Speaking of which, maybe it'd be a good idea to parametrize the subtrans size according to the same (or a similar) formula too. (It might be good to reduce multixact memory consumption too; I'd think that 4+4 pages should be more than sufficient for low memory systems, so making those be half the clog values should be good) So you get both things: reduce memory usage for systems on the low end, which has been slowly increasing lately as we've added more uses of SLRU, and more buffers for large systems. -- Álvaro Herrera <alvhe...@commandprompt.com> The PostgreSQL Company - Command Prompt, Inc. PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
