On Mon, Oct 11, 2010 at 9:29 PM, Josh Berkus <j...@agliodbs.com> wrote: >>>> What is your source for those numbers? They could be right, but I >>>> simply don't know. >>> pg_bench tests with asynch rep and standby_delay = 0. Not rigorous, but >>> enough to show that there is a problem there. Doing pg_bench with a >>> small database >> >> Interesting. > > Yeah, it occurs to me that we can "fix" this with cleanup_delay on the > master, but that's a much worse solution than XID publication from the > standby. It means bloat *all* the time instead of just some of the time.
Yeah, that's worse, I think. > I think we have Yet Another Knob here: users whose standby is > essentially idle will NOT want XID publication, and users whose standby > is for load-balancing will. There probably is a knob, but XID publication ought to be basically free on an idle standby, so the real trade-off is between query cancellation or replay delay on the standby, vs. cluster-wide bloat. >> Sure. But we can't forever ignore the fact that trigger-based >> replication is not as performant as log-based replication. > > Watch me. ;-) s/can't/shouldn't/ ? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers