Re: Exorbitant Parsingtime for view

Hi Marc ,

try reducing the optimizer_max_permutations parameter in init.ora & bounce the DB.
It takes a lot of time to identify the best execution plan by doing permutations.
If bouncing is not possible try this. ( session wise )

SQL>alter session set optimizer_max_permutations=1000; /* default is 80000 */ run your query now. It should take less time.

Hope this may help you.

Regards,

Jayakumar

"Blum, Marc" wrote:

> Dear all,
>
> we have a rather complex View containing several UNIONs and 5-7 tables per
> FROM-clause. Now if I query
>
> SELECT ...
> FROM my_view
> WHERE attribute = 'abc'
>
> the parsing may need 1s. Execution about 0.5s. If I query
>
> SELECT ...
> FROM my_view
> WHERE other_attribute = 'xyz'
>
> the parsing needs 30-45s. Execution about 0.5s. Now I don't want anybody to
> understand our data model or that view. But does anyone has any hints, where
> to start searching? Any experience with such exorbitant parsing?
>
> Thanx in advance
>
> Mit freundlichen Grüßen
>
> i.A. Marc Blum
>
> SOPTIM GmbH
> Grüner Weg 22-24
> D-52070 Aachen
>
> Telefon: +49 241 / 9 18 79-33
> Fax: +49 241 / 15 40 38
>
> mailto:marc.blum_at_soptim.de
> http://www.soptim.de
>
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> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: Blum, Marc
> INET: blum_at_soptim.de
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Received on Wed Oct 18 2000 - 00:06:40 CDT