Re: Pg_upgrade and toast tables bug discovered

On Thu, Sep  4, 2014 at 03:48:17PM -0400, Robert Haas wrote:
> On Thu, Sep 4, 2014 at 3:35 PM, Bruce Momjian <bruce@momjian.us> wrote:
> >> At any rate, I've additionally observed that the relation which is blowing up
> >> pg_upgrade is a VIEW in the source cluster but gets created as a TABLE in the
> >> upgraded cluster, which may better explain why it had no toast table before and
> >> now it does.  Is this some kind of expected behavior for views?
> >
> > Uh, it certainly should not be creating a table instead of a view,
> > though it will get a pg_class entry.
>
> Actually, there's a way this can happen.  If you create two (or more)
> views with circular dependencies between them, then pg_dump will emit
> commands to create one of them as a table first, then create the
> others as views, then convert the first table to a view by adding a
> _SELECT rule to it.

Wow, that's super-interesting.

> If pg_upgrade's logic can't cope with that, that's a bug in
> pg_upgrade, because there's no other way to restore views with
> circular dependency chains.

I don't see why pg_upgrade would have any problem with it as it just
looks at the old schema and post-restore schema.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
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