Re: XX000: tuple concurrently deleted during DROP STATISTICS

On 11/8/23 20:58, Tom Lane wrote:
> Tomas Vondra <tomas(dot)vondra(at)enterprisedb(dot)com> writes:
>> On 11/8/23 16:52, Tom Lane wrote:
>>> Shouldn't DROP STATISTICS be taking a lock on the associated table
>>> that is strong enough to lock out ANALYZE?
>
>> Yes, I think that's the correct thing to do. I recall having a
>> discussion about this with someone while working on the patch, leading
>> to the current code. But I haven't managed to find that particular bit
>> in the archives :-(
>> Anyway, the attached patch should fix this by getting the lock, I think.
>
> This looks generally correct, but surely we don't need it to be as
> strong as AccessExclusiveLock? There seems no reason to conflict with
> ordinary readers/writers of the table.
>
> ANALYZE takes ShareUpdateExclusiveLock, and offhand I think this
> command should do the same.
>

Right. I did copy that from DROP TRIGGER code somewhat mindlessly, but
you're right this does not need block readers/writers.

regards

--
Tomas Vondra
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