Re: Dead Lock problem with 8.1.3

From: Kai Hessing <kai(dot)hessing(at)hobsons(dot)de>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: Dead Lock problem with 8.1.3
Date: 2006-09-28 16:39:35
Message-ID: 4o2c66Fcp656U1@individual.net
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Joe Conway wrote:
> It is possible for a query to run for many days, and still finish. This
> classifies as slow, not hung. The difference is important in
> troubleshooting to determine the cause.

OK, what do you suggest, how long should the process run, until I can
except it not to end?

>>>Also EXPLAIN output, and information regarding the number of rows in
>>>each table, and the number of rows matching veraid = 2 and veraid = 34
>>>might help.
>>
>> Explain produces the same problem. It just takes forever...
>
> Did you try EXPLAIN, or EXPLAIN ANALYZE? The former only does the
> planning, the latter actually materializes the result in order to get
> actual timings, and will therefore take at least as long as the query
> itself.

I got EXPLAIN to work. Please see the full update at Message-ID:
<4o2bkgFclmdhU1(at)individual(dot)net>
So, I don't have to post on different Thread-Branches and can keep the
information together. Thanks ;)

>>>While the query is running, how much CPU is the process consuming, and
>>>what does vmstat show for disk and swap I/O?
>>
>> ~80% CPU power. Disk usage is not noticable.
>
> Can you attach with a debugger and see exactly what's going on? If not
> we'd need that self contained test case to reproduce the problem.

Sorry, I'm currently not able to attach a debugger. I think I'm right
that this means a recompilation of the package would be necessary. The
only thing I was seeing with strace was that the Process is permanently
accessing a file called:
postgresql/8.1/main/base/1740468/pgsql_tmp/pgsql_tmp21938.0

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