Обсуждение: deadlock problem

I'm always getting deadlocks like this:

[30-Mar-2003 19:19:51] PHP Fatal error:  postgres7 error: [0: ERROR:
deadlock detected
] in EXECUTE("INSERT INTO users_foods (user_id, date, meal_id, quantity,
eaten, food_id) VALUES ('55283', '2003-04-07', '1', '1.00', 'f', '779')")in
/usr/local/www/generic/lib/adodb/adodb-errorhandler.inc.phpon line 71
 


Why would an INSERT cause a deadlock problem?  Is this due to the FOR UPDATE
problem with foreign keys?

Chris

Christopher Kings-Lynne wrote:
> I'm always getting deadlocks like this:
> 
> [30-Mar-2003 19:19:51] PHP Fatal error:  postgres7 error: [0: ERROR:
> deadlock detected
> ] in EXECUTE("INSERT INTO users_foods (user_id, date, meal_id, quantity,
> eaten, food_id) VALUES ('55283', '2003-04-07', '1', '1.00', 'f', '779')")
>  in /usr/local/www/generic/lib/adodb/adodb-errorhandler.inc.php on line 71
> 
> 
> Why would an INSERT cause a deadlock problem?  Is this due to the FOR UPDATE
> problem with foreign keys?

Is this in a transaction with other queries?  Are there foreign keys to
other tables that may be causing it.  I don't remember if INSERT locks
foreign tables, but it might.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
359-1001+  If your life is a hard drive,     |  13 Roberts Road +  Christ can be your backup.        |  Newtown Square,
Pennsylvania19073
 

On Mon, 31 Mar 2003, Christopher Kings-Lynne wrote:

> I'm always getting deadlocks like this:
>
> [30-Mar-2003 19:19:51] PHP Fatal error:  postgres7 error: [0: ERROR:
> deadlock detected
> ] in EXECUTE("INSERT INTO users_foods (user_id, date, meal_id, quantity,
> eaten, food_id) VALUES ('55283', '2003-04-07', '1', '1.00', 'f', '779')")
>  in /usr/local/www/generic/lib/adodb/adodb-errorhandler.inc.php on line 71
>
>
> Why would an INSERT cause a deadlock problem?  Is this due to the FOR UPDATE
> problem with foreign keys?

Probably if this table is on either side of one.

Christopher Kings-Lynne wrote:
> I'm always getting deadlocks like this:
> 
> [30-Mar-2003 19:19:51] PHP Fatal error:  postgres7 error: [0: ERROR:
> deadlock detected
> ] in EXECUTE("INSERT INTO users_foods (user_id, date, meal_id, quantity,
> eaten, food_id) VALUES ('55283', '2003-04-07', '1', '1.00', 'f', '779')")
>  in /usr/local/www/generic/lib/adodb/adodb-errorhandler.inc.php on line 71
> 
> 
> Why would an INSERT cause a deadlock problem?  Is this due to the FOR UPDATE
> problem with foreign keys?

I don't suppose a VACUUM is happening at the same time?  I've found
that 7.2.4 likes to give deadlocks during inserts into a table when
it's being VACUUMed (haven't tried it on 7.3.2 yet).


-- 
Kevin Brown                          kevin@sysexperts.com