Re: Do statistics effect the SQL Runtime engine ?

From: Mladen Gogala <>
Date: 17 Feb 2008 13:39:11 +0100
Message-ID: <47b82aef$>

On Wed, 13 Feb 2008 02:30:23 -0800, srivenu wrote:

> I dont think the runtime engine would change the plan that it is
> executing midway. My question is not the impact of stats on the CBO but
> on the runtime engine.
> regards
> srivenu

Srivenu, DBMS_STATS package has "AUTO_INVALIDATE" option which allows you to decide whether you want to immediately recompile all the dependent cursors or not. Also, there is a hidden parameter called "_optimizer_invalidation_period", expressed in seconds, which decides about the time period in which SMON will invalidate the dependent cursors. Here, you can find enlightening discussion about that:

Received on Sun Feb 17 2008 - 06:39:11 CST

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