Re: locking problems - Mailing list pgsql-general

From Andrew Sullivan
Subject Re: locking problems
Date
Msg-id 20020319102842.B13958@mail.libertyrms.com
Whole thread Raw
In response to Re: locking problems  ("Jonathan Ellis" <jbe@familyellis.org>)
Responses Re: locking problems  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
On Sun, Mar 17, 2002 at 08:54:18PM -0800, Jonathan Ellis wrote:

> > something on the table.  Postgres has a deadlock_timeout feature
> > which is there to prevent clients from waiting forever.  What's yours
> > set at?  Maybe you just need to set it higher.
>
> I haven't changed this from the default (~20 seconds?).  Is it a strict
> first-in-first-out queue?  Because there's a lot of other transactions
> trying to update smaller portions of this table that seem to be cutting in
> front of the line for the lock so to speak.

The docs say that if something is locked, the system waits
deadlock_timeout milliseconds before trying to discover whether the
condition can ever become unlocked.  I ran into a problem with
deadlocks under heavy load once, and discovered that setting
deadlock_timeout higher did just what the docs suggested: "Ideally
the setting should exceed your typical transaction time, so as to
improve the odds that the lock will be released before the waiter
decides to check for deadlock."  Maybe that's your problem, too.

A

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Andrew Sullivan                               87 Mowat Avenue
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<andrew@libertyrms.info>                              M6K 3E3
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