Re: Slow performance/response

From: Stephane Faroult <sfaroult_at_roughsea.com>
Date: Tue, 29 Jun 2004 22:28:08 +0200
Message-ID: <40E1D0D8.9020303@roughsea.com>

My feeling is that your query should be split into two or three queries. Parameters passed to handle different cases usually end up in a huge succession of ORs (like here with :full_time), often resulting in full scans when in some cases some extremely valid indexes were here for the taking. Forgive me for not analysing the query in depth, but I have spotted at least three occurrences of student_analytical (let me guess ... Around 10 million rows?). So many auto-joins with in-line views which rely heavily on analytical functions look a bit strange to me and I smell a misuse of those functions. There is an auto-join (somewhere in the middle :)) which could probably be get ridden of. I think that you could rewrite this query to better effect in a shorter time than 3 executions ...

HTH SF

Leroy Kemnitz wrote:

>The query is:
>
>
>
>

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Received on Tue Jun 29 2004 - 15:26:01 CDT