On Fri, 2010-04-30 at 13:58 -0400, Bruce Momjian wrote: > Robert Haas wrote: > > On Fri, Apr 30, 2010 at 1:39 PM, Bruce Momjian <br...@momjian.us> wrote: > > > Robert Haas wrote: > > >> On Fri, Apr 30, 2010 at 12:22 PM, Bruce Momjian <br...@momjian.us> wrote: > > >> > Tom Lane wrote: > > >> >> Heikki Linnakangas <heikki.linnakan...@enterprisedb.com> writes: > > >> >> > Tom Lane wrote: > > >> >> >> If you aren't archiving then there's no guarantee that you'll > > >> >> >> still have > > >> >> >> a continuous WAL series starting from the start of the backup. > > >> >> > > >> >> > I wasn't really thinking of this use case, but you could set > > >> >> > wal_keep_segments "high enough". > > >> >> > > >> >> Ah. ?Okay, that seems like a workable approach, at least for people > > >> >> with > > >> >> reasonably predictable WAL loads. ?We could certainly improve on it > > >> >> later to make it more bulletproof, but it's usable now --- if we relax > > >> >> the error checks. > > >> >> > > >> >> (wal_keep_segments can be changed without restarting, right?) > > >> > > > >> > Should we allow -1 to mean "keep all segments"? > > >> > > >> If that's what you want to do, use archive_mode. > > > > > > Uh, I assume that will require me to store the WAL files somewhere else, > > > rather than keeping them in /pg_xlog, which I thought was the goal. ?Am > > > I missing something? > > > > Well, one of us is. Why would you want to retain all of your WAL logs > > in pg_xlog forever? > > Well, this email thread mentioned a case where you needed to increase > wal_keep_segments to a sufficiently-high value, and of course figuring > out such a value is harder than just having a way of turning off > recycling with -1.
I think the only sensible setting is "as big as my (available) disk space". Any higher and you're going to crash, any lower and you'll invalidate your backup for no reason. -1 emulates current behaviour, BTW Still think we should rename it, in which case 0 is same as "no maximum". -- Simon Riggs www.2ndQuadrant.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers