Re: erroneous restore into pg_catalog schema

On Mon, May 13, 2013 at 12:35 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> I wrote:
>> Another way to fix that inconsistency is to consider that
>> allow_system_table_mods should gate table creations not just drops in
>> pg_catalog.  I'm not real sure why this wasn't the case all along ...
>
> Uh, scratch that last comment: actually, allow_system_table_mods *did*
> gate that, in every existing release.  I bitched upthread about the fact
> that this was changed in 9.3, and did not hear any very satisfactory
> defense of the change.

It disallowed it only for tables, and not for any other object type.
I found that completely arbitrary.  It's perfectly obvious that people
want to be able to create objects in pg_catalog; shall we adopt a rule
that you can put extension there, as long as those extensions don't
happen to contain tables?  That is certainly confusing and arbitrary.

I suppose we could add a GUC, separate from allow_system_table_mods,
to allow specifically adding and dropping objects in pg_catalog.  It
would be consistent, and there would sure be a place to document it.
And it would make it easy to emit the right error-hint.

-- 
Robert Haas
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