Re: Rename of triggers for partitioned tables

On 1/15/21 5:26 PM, Alvaro Herrera wrote:
> On 2020-Nov-27, Arne Roland wrote:
>
>> I got too annoyed at building queries for gexec all the time. So wrote
>> a patch to fix the issue that the rename of partitioned trigger
>> doesn't affect children.
>
> As you say, triggers on children don't necessarily have to have the same
> name as on parent; this already happens when the trigger is renamed in
> the child table but not on parent. In that situation the search on the
> child will fail, which will cause the whole thing to fail I think.
>
> We now have the column pg_trigger.tgparentid, and I think it would be
> better (more reliable) to search for the trigger in the child by the
> tgparentid column instead, rather than by name.
>
> Also, I think it would be good to have
> ALTER TRIGGER .. ON ONLY parent RENAME TO ..
> to avoid recursing to children. This seems mostly pointless, but since
> we've allowed changing the name of the trigger in children thus far,
> then we've implicitly made it supported to have triggers that are named
> differently. (And it's not entirely academic, since the trigger name
> determines firing order.)
>
> Alternatively to this last point, we could decide to disallow renaming
> of triggers on children (i.e. if trigger has tgparentid set, then
> renaming is disallowed). I don't have a problem with that, but it would
> have to be an explicit decision to take.

Arne, thoughts on Álvaro's comments?

Marking this patch as Waiting for Author.

Regards,
--
-David
david(at)pgmasters(dot)net