Re: --single-transaction hack to pg_upgrade does not work

On 2012-12-01 12:14:37 -0500, Tom Lane wrote:
> Andres Freund <andres(at)2ndquadrant(dot)com> writes:
> > On 2012-12-01 12:00:46 -0500, Tom Lane wrote:
> >> ISTM this sort of thing ought to be safe enough, though you probably
> >> need to insist both that the pg_type row's xmin be current XID and
> >> that it not be HEAP_UPDATED.
>
> > I was concerned about updated rows but forgot about HEAP_UPDATED. So I
> > thought that it would be possible to alter the type in some generic
> > fashion (e.g. change owner) and then add new values.
>
> Yeah, I was just thinking about that: we'd have to fail if pg_dump
> emitted CREATE TYPE, ALTER TYPE OWNER, and then tried to add more
> values. Fortunately it doesn't do that; the ADD VALUE business is
> just a multi-statement expansion of CREATE TYPE AS ENUM, and any
> other ALTERs will come afterwards.

Well, there's a binary_upgrade.set_next_pg_enum_oid() inbetween, but thats
luckily just fine.

> > Let me provide something a littlebit more mature.
>
> It could do with some comments ;-)

Hehe, yes. Hopefully this version has enough of that.

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
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