| APPEND hint in Rule and Cost based optimizer [message #434640] |
Thu, 10 December 2009 01:22  |
ganesh104
Messages: 5
Registered: November 2009
Location: India
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Junior Member |
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hi,
There is a select which include hint /*+APPEND*/ while inserting the record. Query is like:
INSERT /*+ APPEND */
INTO Table1 (Col1, Col2, Col3,......)
SELECT (select statemment here)....
This query used to process a batch and post the atm fee charges. Batch was performing good when database was on RULE base optimizer. But now client has upgraded the system and database is on COST based optimizer.
Now this batch is taking too long to execute.
Is there anything to do with this append hint? how this is getting affected on Rule and Cost?
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| Re: APPEND hint in Rule and Cost based optimizer [message #434803 is a reply to message #434679] |
Thu, 10 December 2009 19:35  |
rleishman
Messages: 3728
Registered: October 2005
Location: Melbourne, Australia
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Senior Member |
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I think the hint is a red herring - it is very unlikely to be your problem. Shifting to CBO would only me the hint work (if it wasn't already), which would make the job faster.
Much more likely is that the SELECT part of the INSERT has changed plan since the upgrade. Get an EXPLAIN PLAN under both CBO and RBO and post them here.
Ross Leishman
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