Re: Anyone seen weblogic do this?

From: Tanel Põder <tanel.poder.003_at_mail.ee>
Date: Fri, 2 Jul 2004 16:31:10 +0300
Message-ID: <01da01c46038$d69dd700$e8879fd9@porgand>

If you cannot eliminate these excessive queries by any means, then you could relieve the performance hit by having a local dual synonym pointing to a view uner sys schema whish queries x$dual instead. That way you'd eliminate 3 LIOs per query in 9i (in RAC environment you have to do a little extra trick to query only your instance's row from x$dual).

In 8i there is no x$dual, there you could use a single table hash cluster or IOT with relevant view on it to reduce dual cost (an unique scan on single block IOT takes only 1 LIO compared to 3 that FTS makes on a single block table).

Tanel.

Original Message ----- From: " L. Trindle Gennari" <initltg_at_earthlink.net> To: <oracle-l_at_freelists.org> Sent: Friday, July 02, 2004 4:08 AM Subject: RE: Anyone seen weblogic do this?

> We ran into that too. Did a sql trace on the whole instance and discovered
that it was spending 80% of its time doing select 1 from dual.
>
> ltg
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Received on Fri Jul 02 2004 - 08:27:50 CDT