From: Greg Smith <greg@2ndquadrant.com>
To: Tobias Brox <tobixen@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-performance@postgresql.org
Subject: Re: locking issue on simple selects?
Date: Wed, 15 Sep 2010 20:32:32 -0400
Message-ID: <4C9165A0.4060003@2ndquadrant.com> (raw)
In-Reply-To: <AANLkTim+WH6xXj-P7KVm7gx-7OnB0EEffuumWZ16=UFH@mail.gmail.com>
References: <AANLkTikh++7mouBb7cr2C9zMPKtRffVxDK0QFTf16HLo@mail.gmail.com>
<4096.1284557987@sss.pgh.pa.us>
<AANLkTikzssP3AKeQhM+tB_8tScRGs2iGSqTJJUg2w3DP@mail.gmail.com>
<4C911E58.6030605@2ndquadrant.com>
<AANLkTim+WH6xXj-P7KVm7gx-7OnB0EEffuumWZ16=UFH@mail.gmail.com>
Tobias Brox wrote:
> I think those pages probably should be merged ... hmm ... if
> I manage to solve my locking issues I should probably try and
> contribute to the wiki.
>
Certainly the 3rd one could be merged with one of the other two, and
maybe all merged into one. I haven't cleaned up that whole area in a
whole, it's due for a round of it soon. You're welcome to take a shot at
it. We can always revert any mistakes made.
>> reducing deadlock_timeout.
>>
>
> It's set to one second, and some of the jams we have been experiencing
> has lasted for several minutes. I also think it should say in the pg
> log if there is a deadlock situation?
deadlock_timeout is how long a process trying to acquire a lock waits
before it a) looks for a deadlock, and b) prints a report that it's
waiting into the logs when log_lock_waits is on. So if you're looking
for slow lock acquisition that's in the sub-second range, it can be
useful to reduce regardless of whether deadlock ever happens. That
doesn't sound like your situation though.
--
Greg Smith, 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services and Support www.2ndQuadrant.us
Author, "PostgreSQL 9.0 High Performance" Pre-ordering at:
https://www.packtpub.com/postgresql-9-0-high-performance/book
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To: pgsql-performance@postgresql.org
Cc: greg@2ndquadrant.com, tobixen@gmail.com, tgl@sss.pgh.pa.us
Subject: Re: locking issue on simple selects?
In-Reply-To: <4C9165A0.4060003@2ndquadrant.com>
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