Re: Concurrent MERGE

From: Mark Kirkwood <mark(dot)kirkwood(at)catalyst(dot)net(dot)nz>
To: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Concurrent MERGE
Date: 2010-08-05 23:06:17
Message-ID: 4C5B43E9.7090800@catalyst.net.nz
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On 06/08/10 10:49, Josh Berkus wrote:
>
>> Hm? Please explain what you're talking about.
>>
> Transaction A locks 1 and wants a lock on 2
> Transaction B locks 2 and wants a lock on 3
> Transaction C locks 3 and wants a lock on 1
>
> I've never had the deadlock detector successfully deal with the above.
> Let alone a 4-way.
>
>

Hmm - seems to work ok for me (8.3.11 with pgbench schema updating
branches table by bid):

UPDATE branches SET filler='filled' WHERE bid=:x

I get transaction A succeeds, B is rolled back by the deadlock detector,
C left waiting for A to commit or rollback. What do you find?

Cheers

Mark

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