Re: Rework the way multixact truncations work

On 2015-09-28 21:48:00 -0500, Jim Nasby wrote:
> On 9/28/15 8:49 PM, Robert Haas wrote:
> >If at some point we back-patch this further, then it potentially
> >becomes a live issue, but I would like to respectfully inquire what
> >exactly you think making it a PANIC would accomplish?  There are a lot
> >of scary things about this patch, but the logic for deciding whether
> >to perform a legacy truncation is solid as far as I know.
> 
> Maybe I'm confused, but I thought the whole purpose of this was to get rid
> of the risk associated with that calculation in favor of explicit truncation
> boundaries in the WAL log.

> Even if that's not the case, ISTM that being big and in your face about a
> potential data corruption bug is a good thing, as long as the DBA has a way
> to "hit the snooze button".

So we'd end up with a guc that everyone has to set while they
upgrade. That seems like a pointless hassle.

Greetings,

Andres Freund