On 2014-09-25 09:34:57 -0500, Merlin Moncure wrote: > On Thu, Sep 25, 2014 at 9:14 AM, Andres Freund <and...@2ndquadrant.com> wrote: > >> Why stop at 128 mapping locks? Theoretical downsides to having more > >> mapping locks have been mentioned a few times but has this ever been > >> measured? I'm starting to wonder if the # mapping locks should be > >> dependent on some other value, perhaps the # of shared bufffers... > > > > Wrong way round. You need to prove the upside of increasing it further, > > not the contrary. The primary downside is cache hit ratio and displacing > > other cache entries... > > I can't do that because I don't have the hardware.
One interesting part of this is making sure it doesn't regress older/smaller machines. So at least that side you could check... > what's wrong with trying it out? If somebody is willing to do it: nothing. I'd just much rather do the, by now proven, simple change before starting with more complex solutions. 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
