Josh Berkus wrote:
> I have a couple workloads in my pool which do consume mxids faster than
> xids, due to (I think) execeptional numbers of FK conflicts. It's
> definitely unusual, though, and I'm sure they'd rather have corruption
> protection and endure some more vacuums. If we do this, though, it
> might be worthwhile to backport the multixact age function, so that
> affected users can check and schedule mxact wraparound vacuums
> themselves, something you currently can't do on 9.3.
Backporting that is difficult in core, but you can do it with an
extension without too much trouble. Also, the multixact age function
does not give you the "oldest member" which is what you need to properly
monitor the whole of this; you can add that to an extension too.
--
Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services