Re: Transactional sequence stuff breaks pg_upgrade

On Mon, Jun 12, 2017 at 5:25 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:
> Even there I don't think that's a sane assumption *for the future*. We
> just need a slight change in the rules about when a toast table is needed
> - and that stuff seriously need overhauling - and it doesn't work
> anymore.

The problem is that if a relfilenode ever gets assigned by
GetNewRelFileNode() during a binary-upgrade restore, that OID may turn
out to be used by some other object later in the dump. And then
you're dead, because the dump restore will fail later on complaining
about, well, I forget the error message wording exactly, but,
basically, an OID collision. So if we change the rules in such a way
that objects which currently lack TOAST tables acquire them, we need
to first restore all of the objects *without* adding any new TOAST
tables, and then at the end create any new TOAST tables once we have a
complete list of the relfilenodes that are actually used.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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