| Predicate Informationn in PLAN [message #425033] |
Wed, 07 October 2009 04:26  |
Olivia
Messages: 519
Registered: June 2008
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Senior Member |
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When used with Rule hint a SQL is performing faster compared to
the same sql without hint.
When observed I found the below predicates in SHOW PLAN for the
sql with no hint ( In the plan with Rule I did not find the below predicate)
Does this predicate below may lead to performance issue?
Thanks
Predicate Information (identified by operation id):
---------------------------------------------------
13 - filter("D"."LOCATION_ID" IS NOT NULL)
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| Re: Predicate Informationn in PLAN [message #425060 is a reply to message #425033] |
Wed, 07 October 2009 06:21  |
JRowbottom
Messages: 5933
Registered: June 2006
Location: Sunny North Yorkshire, ho...
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Senior Member |
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If the RBO performs better than the CBO, then it generally suggests that your statistics are out of date.
The predicate information is not present in the RBO plan because the RBO does not bother with minor details like values of columns when composing it's execution plan.
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| Re: Predicate Informationn in PLAN [message #425123 is a reply to message #425071] |
Wed, 07 October 2009 11:21 |
JRowbottom
Messages: 5933
Registered: June 2006
Location: Sunny North Yorkshire, ho...
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Senior Member |
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Can you post the plans of the two versions?
You're not doing something silly like running the query normally, and then running the RBO version, and noticing only the performance improvement caused by the blocks all being in memory for the second query, are you?
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