Re: pg_dumpall Sets Roll default_tablespace Before Creating Tablespaces

On Wed, Oct 19, 2011 at 7:46 PM, Florian Pflug <fgp(at)phlo(dot)org> wrote:
> On Oct20, 2011, at 01:19 , Tom Lane wrote:
>> Florian Pflug <fgp(at)phlo(dot)org> writes:
>>> Taking this even further, why do we bother with non-immutable (i.e.,
>>> depending on the database's contents) checks during ALTER ROLE/DATABASET SET
>>> at all?
>>
>> Yeah, I was wondering about that one too.  It would not solve all the
>> problems here, but skipping validity checks would fix some of them.
>> The trouble of course is what happens if the value is found to be bad
>> when you try to use it ...
>
> Presumably we'd detect that during logon, because the GUC assignment
> hook will quite probably complain. I'd vote for emitting a warning in
> that case. This is also what we due currently if we fail to set the
> GUC to the desired value due to permission issues
>
> postgres=# create role r1 login;
> CREATE ROLE
> postgres=# create role r2;
> CREATE ROLE
> postgres=# alter role r1 set role = r2;
> ALTER ROLE
> postgres=# \connect - r1
> WARNING:  permission denied to set role "r2"
> WARNING:  permission denied to set role "r2"
> You are now connected to database "postgres" as user "r1".
>
> (Dunno why that WARNING appears twice)
>
> Since an ALTER DATABASE/ROLE SET doesn't prevent the user from overriding
> the value, ignoring invalid settings shouldn't be a security risk.

I didn't realize these dependencies weren't immutable. If that is the
desired behavior, then I agree a warning should be sufficient to catch
typo's and oversights.

If you did want to make them immutable, I also like Florian's idea of
a dependency graph. This would make the dumps less readable though.

>
> best regards,
> Florian Pflug
>
>
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