Friday, May 23, 2008

Re: [SQL] Extremely Low performance with ODBC

Thanks.. All logs are already off and I'm just sending one query directly
from the application (from Visual Foxpro using SQL Pass through and in
VB.net using ado.net). I've found that the "problem" is that I'm using
implicit joins, and when I change it to explicit Inner Joins the query only
takes 3 seconds (as with PgAdmin). I still can't understand if the problem
resides on the ODBC driver, the Query Planner or it's just a mix of both.

-----Mensaje original-----
De: Richard Broersma [mailto:richard.broersma@gmail.com]
Enviado el: Viernes, 23 de Mayo de 2008 01:04 p.m.
Para: Sebastian Rychter
CC: pgsql-sql@postgresql.org
Asunto: Re: [SQL] Extremely Low performance with ODBC

On Thu, May 22, 2008 at 11:29 AM, Sebastian Rychter
<srychter@anvet.com.ar> wrote:
> Hi, I'm executing a query through psql ODBC which is taking around 2
minutes
> to complete. When I run it from PgAdmin it takes less than 3 seconds.
>
> Any idea ?

1) turn off all ODBC query logging from both the ODBC driver and the
ODBC administrator. This feature is a performance killer. Only use
this feature if you are trying to debug a problem.
2) Some client programs try to perform the joins on the client side
rather than the server side. I would check if the client is actually
passing the actual SQL statement back to the server. If it is trying
to perform the join on the client, it could be a big performance
killer.

--
Regards,
Richard Broersma Jr.

Visit the Los Angles PostgreSQL Users Group (LAPUG)
http://pugs.postgresql.org/lapug

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