Re: pg_dump is broken for partition tablespaces

Hi,

On 2019-04-22 14:16:28 -0400, Alvaro Herrera wrote:
> On 2019-Apr-22, Robert Haas wrote:
>
> > PostgreSQL has historically and very deliberately *not made a
> > distinction* between "this object is in the default tablespace" and
> > "this object is in tablespace X which happens to be the default." I
> > think that it's too late to invent such a distinction for reasons of
> > backward compatibility -- and if we were going to do it, surely it
> > would need to exist for both partitioned tables and the partitions
> > themselves. Otherwise it just produces more strange inconsistencies.
>
> Yeah, this is probably right. (I don't think it's the same thing that
> Tom was saying, though, or at least I didn't understand his argument
> this way.)
>
> I think we can get out of this whole class of problems by forbidding the
> TABLESPACE clause for partitioned rels from mentioning the database
> tablespace -- that is, users either mention some *other* tablespace, or
> partitions follow default_tablespace like everybody else. AFAICS with
> that restriction this whole problem does not arise, and the patch may
> become simpler. I'll give it a spin.

Why is the obvious answer is to not just remove the whole tablespace
inheritance behaviour? It's obviously ambiguous and hard to get right.
I still don't see any usecase that even comes close to making the
inheritance useful enough to justify the amount of work (code, tests,
bugfixes) and docs that are required.

Greetings,

Andres Freund