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Home -> Community -> Mailing Lists -> Oracle-L -> RULE vs. CHOOSE
Qs. Will COST Based Optimizer (CBO) or Rule Based Optimizer (RBO) be used for the PARTITIONED Table in the Following Query ?
NOTE OPTIMIZER_MODE is Set Explicitly to RULE , Run the Following SQL :-
SELECT <Some Columns>
FROM <Partition Table> , <NON-Partitioned Table>
where <Partition Table>.Column = <NON-Partitioned Table>.Column
Assuming <Partition Table>.Column is the PARTITION KEY & BOTH <Partition Table> & <NON-Partitioned Table> are ANALYZED .
Qs. Will Only the Respective partition be SCANNED in the Above Query ? Qs. Would there be Any Disadvantage in SETTING OPTIMIZER_MODE=RULE for the Above Query ?
Most of the Tables in the Application may be NON-partitioned & Most of the Queries RUN Well in RULE .
Qs. How is it Best Possible to KEEP the SAME (BEST) Execution Plan at Various Sites where the SAME PRODUCT Exists
NOTE - These Sites Belong to DIFFERENT Customers & Have Different Total Data Size & Distributions .
Current Data Size ranges from 50 to 150 GB but the Data is Growing Very Rapidly & may touch 200 GB within the Year .
Being a Banking Application Product , it is a MIX of OLTP & DSS Types of Transactions .
With OPTIMIZER_MODE set to RULE the Queries work Quite Well .
Qs. Is there any PACKAGE etc. which Automatically Causes Statistics to be ANALYZED in some SMALL proportions (Bit by Bit) while Live Operations are in progress ? What would be the Overhead of Such a Package (if Exists) ?
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Please see the official ORACLE-L FAQ: http://www.orafaq.com
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Author: VIVEK_SHARMA
INET: VIVEK_SHARMA_at_infy.com
Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Liststo: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Wed Aug 01 2001 - 01:08:32 CDT
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