Re: Anyone seen this kind of lock pileup?

>> What's odd about this is that the resulting "lock pileup" takes a
>> mysterious 2-3.5 seconds to clear, despite the fact that none of the
>> connections are *doing* anything during that time, nor are there
>> deadlock errors.  In theory at least, the locks should clear out in
>> reverse order in less than a second; none of the individual statements
>> takes more than 10ms to execute.

Ok, I've collected more data.   Looks like the case I was examining was
idiosyncratic; most of these lock pile-ups involve 400 or more locks
waiting held by around 20 different backends.  Given this, taking 3
seconds to sort that all out doesn't seem that unreasonable.
Presumably there's a poll cycle of some sort for waiting statements?

Anyway, the obvious answer is for the user to fix their application.

--
                                  -- Josh Berkus
                                     PostgreSQL Experts Inc.
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