RE: When optimizer reevaluate SQL statement

I'm afraid I can't agree with the statement that two different users submitting the same SQL cause a hard parse. It is my understanding of the process that part of the parsing occurs when another user is submitting an identical SQL statement, but this does not constitute a hard parse, just a check of permissions, synonyms, etc. If there was a hard parse everytime a different user submitted identical SQL it would negate much of the benefit of using bind variables. Thus the answer is that there is reparsing, but not the kind that really does damage to performance.

Regards,
Chris Gait

On 14 Sep 2001, at 9:55, Christopher Spence wrote:

Date sent:              Fri, 14 Sep 2001 09:55:33 -0800
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> !! Please do not post Off Topic to this List !!
>
> If the Oracle executing user is different, the execution plan will be
> different due to possibility of different objects and security.
>
> Different sessions under the same user can share using bind variables.
>
> "Do not criticize someone until you walked a mile in their shoes, that way
> when you criticize them, you are a mile a way and have their shoes."
>
> Christopher R. Spence
> Oracle DBA
> Phone: (978) 322-5744
> Fax: (707) 885-2275
>
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>
>
> -----Original Message-----
> Sent: Friday, September 14, 2001 12:25 PM
> To: Multiple recipients of list ORACLE-L
>
> !! Please do not post Off Topic to this List !!
>
> Chris:
>
> > If you are executing it under a different user the statement will be
> reparsed.
>
> I'm puzzled. I always thought that different users submitting the identical
> SQL statement would use the same plan and not need to be reparsed. I
> understood that to be part of the reasoning behind bind variables and the
> big advantage of cursor sharing. Please explain.
>
> Jon Walthour
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