set optimizer_features_enable to lower version SQL run faster?

From: dba1 mcc <mccdba1_at_yahoo.com>
Date: Tue, 2 Feb 2010 15:09:27 -0800 (PST)
Message-ID: <80852.6435.qm_at_web65707.mail.ac4.yahoo.com>



we have ORACLE enterprise version 10.2.0.4 on LINUX. recently we found some SQL statemnets run very slow (even we run analyze statistics). But if we set optimizer_features_enable to lower version it run much faster. Following is data we got:

When the SQL is run with OPTIMIZER_FEATURE_ENABLE=

 10.2.0.4 73 seconds

 10.2.0.3 50 seconds

 9 30 seconds

 8 1 second.

  1. does there has some way we can do (NOT set optimizer_features_enable to lower version) still get better SQL performance?
  2. if unfortunately we need set 'optimizer_feature_enable to lower version like 8.0) does database will have any problem?

Thanks.       

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Received on Tue Feb 02 2010 - 17:09:27 CST

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