On Wed, Oct 19, 2016 at 8:47 AM, Bruce Momjian <br...@momjian.us> wrote: > On Wed, Oct 19, 2016 at 08:33:20AM -0400, Robert Haas wrote: >> On Tue, Oct 18, 2016 at 4:33 PM, Josh Berkus <j...@agliodbs.com> wrote: >> > Based on that argument, we would never be able to remove any >> > configuration parameter ever. >> >> Well... no. Based on that argument, we should only remove >> configuration parameters if we're fairly certain that they are not >> useful any more, which will be rare, but is not never. I agree that >> *if* vacuum_defer_cleanup_age is no longer useful, it should be >> removed. I'm just not convinced that it's truly obsolete, and you >> haven't really offered much of an argument for that proposition. It >> does something sufficiently different from hot_standby_feedback that >> I'm not sure it's accurate to say that one can substitute for the >> other, and indeed, I see Andres has already suggested some scenarios >> where it could still be useful. >> >> Actually, I think vacuum_defer_cleanup_age is, and always has been, an >> ugly hack. But for some people it may be the ugly hack that is >> letting them continue to use PostgreSQL. > > I see vacuum_defer_cleanup_age as old_snapshot_threshold for standby > servers --- it cancels transactions rather than delaying cleanup.
I think it's the opposite, isn't it? vacuum_defer_cleanup_age prevents cancellations. -- 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