RE: Long Parse Time

With a 8-table join this probably isn't the root cause as you've got max 40k join order permutations - that's including all cartesian join orders, which aren't all evaluated by default, _optimizer_search_limit limits the max number of cartesian join orders to be evaluated (120 by default (factorial of 5 = 120)). On the other hand, both these parameters are worth checking. If parsing a 8-table join takes 10s of seconds, it's either a bug or someone has been playing with undocumented parameters.
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Regards,
Tanel Poder
http://blog.tanelpoder.com <http://blog.tanelpoder.com/>

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Allen, Brandon
Sent: 06 May 2009 21:44
To: ric.van.dyke_at_hotsos.com; oracle-l_at_freelists.org Subject: RE: Long Parse Time

One more thing I forgot to mention - did you check your _optimizer_max_permutations parameter to make sure somebody didn't increase it from the default? Another workaround if you're desperate (not generally recommended!) could be to reduce this parameter from the default of 2000.  

Regards,

Brandon    

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http://www.freelists.org/webpage/oracle-l Received on Wed May 06 2009 - 14:49:15 CDT