Re: Why my query plan changed ?

From: Dennis Williams <oracledba.williams_at_gmail.com>
Date: Wed, 17 Sep 2008 08:48:04 -0500
Message-ID: <de807caa0809170648m66da02a9k59b20f24815bef24@mail.gmail.com>


Ajay,

I haven't worked with CURSOR_SHARING, so I cannot give you an answer based on experience, but just speculation. Perhaps someone else on the list has better advice.

    Since the goal of CURSOR_SHARING=FORCE is to avoid continual parsing and optimizing, I would assume that when you submit a SQL statement to Oracle, it is first converted to an equivalent statement with bind variables, and then Oracle will search for an existing equivalent SQL statement, and if it finds one, will use that execution plan. Therefore in answer to your question, I would assume that CURSOR_SHARING=FORCE would have the same side effect, that whatever execution plan is generated, all subsequent queries will share it.

Dennis Williams

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Received on Wed Sep 17 2008 - 08:48:04 CDT

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