Re: Replication identifiers, take 4

On 2015-04-08 14:17:04 +0200, Petr Jelinek wrote:
> And you guys are not getting my point. What I proposed was to not reuse the
> RI id immediately because that can make debugging issues with
> replication/conflict handling harder when something happens after cluster
> configuration has changed.

If that's the goal, you shouldn't delete the replication identifier at
that point. That's the only sane way preventing it from being reused.

> Whether it's done using Oid or some other way, I don't really care and
> wrapping around eventually is ok, since the old origin info for
> transactions will be cleared out during the freeze at the latest
> anyway.

How are you proposing to do the allocation then? There's no magic
preventing immediate reuse with oids or anything else. The oid counter
might *already* have wrapped around and point exactly to the identifier
you're about to delete. Then when you deleted it it's going to be reused
for the next allocated oid.

Andres Freund