RE: default optimizer_mode=ALL_ROWS in 10g windows

From: Jacques Kilchoer <Jacques.Kilchoer_at_quest.com>
Date: Wed, 18 Aug 2004 18:42:02 -0700
Message-ID: <B5C5F99D765BB744B54FFDF35F60262119FC42@irvmbxw02>

In 9.2 the default for OPTIMIZER_MODE was CHOOSE. CHOOSE meant use the rule-based optimizer if none of the tables in the query have statistics. In Oracle 10.1 the Rule-based optimizer is officially "desupported" (see metalink note notice 189702.1). So CHOOSE is no longer a valid option. Therefore the default has been changed. Why is the default ALL_ROWS instead of FIRST_ROWS_1, for example? That I don't know.

-----Original Message-----

jaysingh1_at_optonline.net

Does anybody have an idea why oracle made default optimizer_mode=ALL_ROWS in 10g windows. I didn't check other platforms.

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Received on Wed Aug 18 2004 - 20:37:44 CDT