Re: BUG #17268: Possible corruption in toast index after reindex index concurrently

Hi,

On November 8, 2021 7:56:24 PM PST, Noah Misch <noah@leadboat.com> wrote:
>On Mon, Nov 08, 2021 at 12:36:41PM -0800, Andres Freund wrote:
>> One possible way to fix this would be to make ReindexRelationConcurrently()
>> acquire a lock on the underlying table when reindexing a toast table. Another
>> to not release the lock in toast_save_datum().
>
>The latter is more future-proof.  Does it have material disadvantages?

I don't immediately see any. But I've been long of the opinion, and had plenty discussions around it, that our habit of
releasinglocks early is far too widely used. 

I do however wonder if there's other path to the problem, besides saving toast datums. We also release those locks
earlyin other places, and while e.g. r/o locks won't cause a problem with this specific interlock, it could cause
problemaround dropping the relation, for example. 

Andres
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