Re: [HACKERS] [BUGS] Concurrent ALTER SEQUENCE RESTART Regression

On 5/11/17 16:34, Andres Freund wrote:
>>> This'd probably need to be removed, as we'd otherwise would get very
>>> weird semantics around aborted subxacts.
>> Can you explain in more detail what you mean by this?
> Well, right now we don't do proper lock-tracking for sequences, always
> assigning them to the toplevel transaction.  But that doesn't seem
> proper when nextval() would conflict with ALTER SEQUENCE et al, because
> then locks would continue to be held by aborted savepoints.

I see what you mean here.  We already have this issue with DROP SEQUENCE.

While it would be nice to normalize this, I think it's quite esoteric.
I doubt users have any specific expectations how sequences behave in
aborted subtransactions.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
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