Re: [BUG] Fix DETACH with FK pointing to a partitioned table fails

Alvaro Herrera <alvherre@alvh.no-ip.org>

From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Tender Wang <tndrwang@gmail.com>
Cc: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>, Junwang Zhao <zhjwpku@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, Alexander Lakhin <exclusion@gmail.com>, Guillaume Lelarge <guillaume@lelarge.info>, Michael Paquier <michael@paquier.xyz>
Date: 2024-10-21T21:52:18Z
Lists: pgsql-hackers

Attachments

On 2024-Oct-21, Tender Wang wrote:

> I suspect that we don't need the below if
> statement anymore.
> /*
> * If the referenced side is partitioned (which we know because our
> * parent's constraint points to a different relation than ours) then
> * we must, in addition to the above, create pg_constraint rows that
> * point to each partition, each with its own action triggers.
> */
> if (parentConForm->conrelid != conform->conrelid)
> {
> ...
> }
> 
> The above contidion is always true according to my test.
> I haven't figured out an anti-case.

You're right, this is useless, we can remove the 'if' line.  I kept the
block though, to have a place for all those local variable declarations
(otherwise the code looks messier than it needs to).

I also noticed that addFkRecurseReferenced() is uselessly taking a List
**wqueue argument but doesn't use it, so I removed it (as fallout, other
routines don't need it either, especially DetachPartitionFinalize).  I
added some commentary on the creation of dependencies in
addFkConstraint().

I also include a few other cosmetic changes; just comment layout
changes.

This time I attach the patch for master only; the others have changed
identically.  14 is unchanged from before.  I figured that the conflict
from 14 to 13 was trivial to resolve -- it was just because of DETACH
CONCURRENTLY, so some code moves around, but that's all that happens.

-- 
Álvaro Herrera        Breisgau, Deutschland  —  https://www.EnterpriseDB.com/

Commits

  1. Fix some more bugs in foreign keys connecting partitioned tables

  2. Restructure foreign key handling code for ATTACH/DETACH

  3. Create foreign key triggers in partitioned tables too