Re: Influence Optimzer to merge 'IN' subquery

On 9 Feb 2005 08:29:50 -0800, mccmx_at_hotmail.com (Matt) wrote:

>
>So how can I force Oracle to evaluate the subquery first and use the
>value as part of the index range scan of the large table.

There is PUSHQ or a PUSHD hint (don't exactly remember) to accomplish this.
However, is there any chance value_group is null allowed? Tom Kyte in his book shows this influences the way NOT IN subqueries are handled, this might also apply to IN subqueries. Guess you'd better post the full plan, and information on the indexes present on the main table.

Usually, btw, transforming an IN subquery to an EXISTS correlated subquery still works.

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Sybrand Bakker, Senior Oracle DBA