Do statistics effect the SQL Runtime engine ?
Date: Tue, 12 Feb 2008 10:40:04 -0800 (PST)
I have a question regarding statistics and SQL runtime engine. The oracle CBO uses statistics to generate the PLAN. Once the plan is generated, the runtime engine starts working on it. My question is whether the runtime engine changes the method of plan execution according to the statistics.
As an example - Lets say i have a simple SQL with a join between 2 tables X & Y.
Lets say depending on the stats, the CBO decides on a HASH JOIN between X & Y.
Now when the runtime engine starts working on the plan, does it decision on to go for a optimal workarea or a one-pass workarea or a multipass depend on the statistics that it expects from the rowsources ?
srivenu Received on Tue Feb 12 2008 - 12:40:04 CST