On Thu, Nov 20, 2014 at 9:21 PM, Josh Berkus <josh@agliodbs.com> wrote:
> Well, the first thing that comes to mind is that template0 should be
> "permanently frozen". That is, all objects in it should be created with
> frozen xid and mxids. After all, nobody can modify anything in it.
This is actually the way it used to be. It was changed because it was discovered there was some case where an unfrozen xid would end up in template0 anyways and for some reason it was hard to be sure to avoid it. I don't recall exactly what the situation was that triggered it but the argument was made then that it was safest to just include template0 in autovacuum rather than depend on getting this 100% right and risk corruption.
--
greg
