pg.ddx.io  pgsql-performance@postgresql.org mailing list archive  

help / color / mirror / Atom feed

Attempting to disable count triggers on cleanup
3+ messages / 2 participants
[nested] [flat]

* Attempting to disable count triggers on cleanup
@ 2007-09-25 11:08  Dave Cramer <pg@fastcrypt.com>
  0 siblings, 1 reply; 3+ messages in thread

From: Dave Cramer @ 2007-09-25 11:08 UTC (permalink / raw)
  To: pgsql-performance

I have a database that we want to keep track of counts of rows.

We have triggers on the rows which increment, and decrement a count 
table. In order to speed up deleting many rows we have added the following

   if user != 'mocospace_cleanup' 
then                                                                          

        update user_profile_count set buddycount=buddycount-1 where 
user_profile_count.uid=OLD.userid;      
    end 
if;                                                                                                      


However in the logs we can see the following. I have checked to make 
sure that the user really is the mocospace_cleanup user and checked 
manually by logging in as the mocospace_cleanup user to make sure that 
the code above does what it purports to.

ERROR:  deadlock detected
DETAIL:  Process 23063 waits for ExclusiveLock on tuple (20502,48) of 
relation 48999028 of database 14510214; blocked by process 23110.
Process 23110 waits for ShareLock on transaction 1427023217; blocked by 
process 23098.
...
CONTEXT:  SQL statement "update user_profile_count set 
buddycount=buddycount-1 where user_profile_count.uid= $1 "
PL/pgSQL function "user_buddy_count" line 11 at SQL statement
SQL statement "DELETE FROM ONLY "public"."user_buddies" WHERE 
"buddyuserid" = $1"

Dave



^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: Attempting to disable count triggers on cleanup
@ 2007-09-25 11:21  hubert depesz lubaczewski <depesz@depesz.com>
  parent: Dave Cramer <pg@fastcrypt.com>
  0 siblings, 1 reply; 3+ messages in thread

From: hubert depesz lubaczewski @ 2007-09-25 11:21 UTC (permalink / raw)
  To: Dave Cramer <pg@fastcrypt.com>; +Cc: pgsql-performance

On Tue, Sep 25, 2007 at 07:08:42AM -0400, Dave Cramer wrote:
> ERROR:  deadlock detected
> DETAIL:  Process 23063 waits for ExclusiveLock on tuple (20502,48) of 
> relation 48999028 of database 14510214; blocked by process 23110.
> Process 23110 waits for ShareLock on transaction 1427023217; blocked by 
> process 23098.
> ...
> CONTEXT:  SQL statement "update user_profile_count set 
> buddycount=buddycount-1 where user_profile_count.uid= $1 "
> PL/pgSQL function "user_buddy_count" line 11 at SQL statement
> SQL statement "DELETE FROM ONLY "public"."user_buddies" WHERE 
> "buddyuserid" = $1"

take a look at:
http://www.depesz.com/index.php/2007/09/12/objects-in-categories-counters-with-triggers/

and if you want to temporarily disable trigger, simply do appropriate
"alter table disable trigger".

depesz

-- 
quicksil1er: "postgres is excellent, but like any DB it requires a
highly paid DBA.  here's my CV!" :)
http://www.depesz.com/ - blog dla ciebie (i moje CV)



^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: Attempting to disable count triggers on cleanup
@ 2007-09-25 11:39  Dave Cramer <pg@fastcrypt.com>
  parent: hubert depesz lubaczewski <depesz@depesz.com>
  0 siblings, 0 replies; 3+ messages in thread

From: Dave Cramer @ 2007-09-25 11:39 UTC (permalink / raw)
  To: depesz@depesz.com; +Cc: pgsql-performance

hubert depesz lubaczewski wrote:
> On Tue, Sep 25, 2007 at 07:08:42AM -0400, Dave Cramer wrote:
>   
>> ERROR:  deadlock detected
>> DETAIL:  Process 23063 waits for ExclusiveLock on tuple (20502,48) of 
>> relation 48999028 of database 14510214; blocked by process 23110.
>> Process 23110 waits for ShareLock on transaction 1427023217; blocked by 
>> process 23098.
>> ...
>> CONTEXT:  SQL statement "update user_profile_count set 
>> buddycount=buddycount-1 where user_profile_count.uid= $1 "
>> PL/pgSQL function "user_buddy_count" line 11 at SQL statement
>> SQL statement "DELETE FROM ONLY "public"."user_buddies" WHERE 
>> "buddyuserid" = $1"
>>     
>
> take a look at:
> http://www.depesz.com/index.php/2007/09/12/objects-in-categories-counters-with-triggers/
>
> and if you want to temporarily disable trigger, simply do appropriate
> "alter table disable trigger".
>
>   
Well, that doesn't work inside a transaction I've tried it. This has 
been fixed in 8.3

Dave
> depesz
>
>   




^ permalink  raw  reply  [nested|flat] 3+ messages in thread

end of thread, other threads:[~2007-09-25 11:39 UTC | newest]

Thread overview: 3+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2007-09-25 11:08 Attempting to disable count triggers on cleanup Dave Cramer <pg@fastcrypt.com>
2007-09-25 11:21 ` hubert depesz lubaczewski <depesz@depesz.com>
2007-09-25 11:39   ` Dave Cramer <pg@fastcrypt.com>

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox