On Wed, Jan 5, 2011 at 23:58, Dimitri Fontaine <dimi...@2ndquadrant.fr> wrote: >> * Stefan mentiond it might be useful to put some >> posix_fadvise(POSIX_FADV_DONTNEED) >> in the process that streams all the files out. Seems useful, as long as >> that >> doesn't kick them out of the cache *completely*, for other backends as >> well. >> Do we know if that is the case? > > Maybe have a look at pgfincore to only tag DONTNEED for blocks that are > not already in SHM?
It's not much of an improvement. For pages that we already have in shared memory, OS cache is mostly useless. OS cache matters for pages that *aren't* in shared memory. Regards, Marti -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
