On Tue, Feb 08, 2011 at 10:14:44AM -0600, Kevin Grittner wrote: > I do have some concern that if this defaults to too low a number, > those who try SSI without bumping it and restarting the postmaster > will not like the performance under load very much. SSI performance > would not be affected by a low setting under light load when there > isn't a long-running READ WRITE transaction.
If we're worried about this, we could add a log message the first time SummarizeOldestCommittedXact is called, to suggest increasing the GUC for number of SerializableXacts. This also has the potential benefit of alerting the user that there's a long-running transaction, in case that's unexpected (say, if it were caused by a wedged client) I don't have any particular opinion on what the default value of the GUC should be. Dan -- Dan R. K. Ports MIT CSAIL http://drkp.net/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
