Magnus Hagander wrote: > O_DIRECT helps us when we're not going to read the file again, because > we don't waste cache on it. If we are, which is the case here, it > should be really bad for performance, since we actually have to do a > physical read. > > Incidentally, that should also apply to general WAL when archive_mdoe > is on. Do we optimize for that?
Hmm, no we don't. We do take that into account so that we refrain from issuing posix_fadvice(DONTNEED) if archive_mode is on, but we don't disable O_DIRECT. Maybe we should.. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
