Re: BUG #6704: ALTER EXTENSION postgis SET SCHEMA leaves dangling relations

From: Dimitri Fontaine <dimitri(at)2ndQuadrant(dot)fr>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, Bruce Momjian <bruce(at)momjian(dot)us>, jeff <jeff(at)pgexperts(dot)com>, Pg Bugs <pgsql-bugs(at)postgresql(dot)org>
Subject: Re: BUG #6704: ALTER EXTENSION postgis SET SCHEMA leaves dangling relations
Date: 2012-09-24 08:26:52
Message-ID: m2a9wf967n.fsf@2ndQuadrant.fr
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-bugs

Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
> I've got to say that I think this is fundamentally the wrong approach:
> rather than fixing the generic problem of ALTER EXTENSION not coping
> with multiple dependency paths to the same object, it hacks the specific
> case of owned sequences, and what's more it does that by assuming that
> every owned sequence *will* have a dependency on the extension. That's
> not a safe assumption.

In general, agreed.

> Still, this might be the best approach for the back branches, given that
> we do not know of any existing multiple-dependency scenarios other than
> the owned-sequence case. A real fix is looking mighty invasive.

That's what I was aiming at, best approach for the back branches.

>> Even for TIP I don't want us to change how pg_depend tracking is done,
>
> Agreed. Quite aside from backwards-compatibility concerns, I think that
> trying to avoid multiple dependency paths is doomed to failure.

For a “DIRTT” approach to the problems, I think Álvaro's work is in the
right direction, and should be pursued without trying to address the
back branches too. I don't remember now if his tracking attempt was also
trying to change pg_depend entries, I think that was in two separate
patches versions.

DIRTT: Do It Right This Time

Álvaro, do you want to be working on a master only version of the fix
or do you want me to?

Regards,
--
Dimitri Fontaine 06 63 07 10 78
http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support

In response to

Responses

Browse pgsql-bugs by date

  From Date Subject
Next Message raphael.petit 2012-09-24 11:37:34 BUG #7564: window installer of Postgresql 9.2 and service configuration
Previous Message Tom Lane 2012-09-24 03:04:20 Re: BUG #6704: ALTER EXTENSION postgis SET SCHEMA leaves dangling relations