Re: lock on object is already held

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Daniel Wood <dwood(at)salesforce(dot)com>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: lock on object is already held
Date: 2013-11-28 19:35:23
Message-ID: 17227.1385667323@sss.pgh.pa.us
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I wrote:
> Daniel Wood <dwood(at)salesforce(dot)com> writes:
>> Does the original version of my stress test not repro the problem on 9.2?

> [ tries it ... ] No, it doesn't, or at least the MTBF is a couple orders
> of magnitude better than on 9.3.

Oh, of course: the reason the test doesn't fail as given on 9.2 is that
9.2 doesn't have a lock_timeout parameter. (I missed the complaints about
this in the blizzard of other noise the test generates :-(.) The timeout
is critical to exposing the bug because it needs failed lock acquisitions.
Probably unpatched 9.2 would fall over if you used statement_timeout
instead.

regards, tom lane

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