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

Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> 于2024年10月28日周一 17:16写道：

> On 2024-Oct-27, Tender Wang wrote:
>
> > BTW, while reviewing the v2 patch, I found the parentConTup in
> > foreach(cell, fks) block
> > didn't need it anymore. We can remove the related codes.
>
> True. Done so in this v3.
>
> I noticed another problem here: we're grabbing the wrong lock type on
> the referenced rel (AccessShareLock) during detach. (What's more: we
> release it afterwards, which is the wrong thing to do. We need to keep
> such locks until end of transaction). I didn't try to construct a case
> where this would be a problem, but if I change AccessShare to NoLock,
> the assertion that says we don't hold _any_ lock on that relation fires,
> which means that we're not taking any locks on those rels before this
> point. So this lock strength choice is definitely wrong. I changed it
> to ShareRowExclusive, which is what we're suppose to use when adding a
> trigger.

In CloneFKReferencing(), the constrForm->confrelid uses the same lock type.
I think you're right. I don't find any other problem.

--
Thanks,
Tender Wang