Re: Do statistics effect the SQL Runtime engine ?
Date: 17 Feb 2008 13:39:11 +0100
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.
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: http://forums.oracle.com/forums/thread.jspa?threadID=592771&tstart=30Received on Sun Feb 17 2008 - 06:39:11 CST