try:
     
     Perform table transaction
     break
except:
     rollback
     delay
     try again to perform table transaction

I'm sure you will get the gist of the above and why.  I also set my 
isolation_level to READ UNCOMMITED.

Thanks,
Garyc

     
--- On Thu, 5/6/10, rajasekhar911 <rajasekhar...@gmail.com> wrote:

> From: rajasekhar911 <rajasekhar...@gmail.com>
> Subject: [sqlalchemy] how to handle deadlock
> To: "sqlalchemy" <sqlalchemy@googlegroups.com>
> Date: Thursday, May 6, 2010, 5:23 AM
> Hi
> 
> I am using sqlalchemy0.5.5 in my TG2 app with mysql(innodb)
> database
> My applicaton is multithreaded.
> there are multiple tasks that run at certain intervals.
> in one of my tables i am getting the following deadlock
> error.
> Deadlock found when trying to get lock; try restarting
> transaction
> 
> the query was failing while trying to delete in the
> following way.
> DBSession.query(Metrics).filter(Metrics.type_id==type_id).filter(Metrics.cdate
> <= date1).delete()
> 
> so i changed the code to
> rows =
> DBSession.query(Metrics).filter(Metrics.type_id==type_id).filter(Metrics.cdate
> <= date1).all()
> for row in rows :
>     DBSession.delete(row)
> assuming that it will scan less no:of rows while deleting.
> In this way
> i am no longer seeing the deadlock error.
> but if anybody can clarify that this is reliable enough or
> suggest any
> other options ,
> that would be really helpful
> 
> thanks
> 
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