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Keith,
To my
knowledge, RBO has not changed. That includes NOT dealing w/ IOT.
So, I think if you execute a query that references an IOT, you'll implicitly
invoke the CBO. That would explain why the plan is changing. So, did
you change a table from heap to IOT when you moved to 9i? If so, that's
what's invoking CBO.
-Mark
PS fatcity is going away, use freelists.org!
Mark J.
Bobak
Oracle DBA
ProQuest Company
Ann Arbor,
MI
"Imagination
was given to man to compensate him for what he is not, and a sense of humor was
provided to console him for what he is." --Horace
Walpole
We move an application that uses
OPTIMIZER_MODE=RULE from Oracle8 to 9i. Most of it is fine, but there are two
queries that have a very different execution plan. In one case, the execution
time increases from less than a minute to more than an hour. Neither query
uses any of the new Oracle 9i features.
My understanding is that the Rule optimizer code
has not changed, except to account for new features like IOT's. Has anyone
else seen this type of behavior?
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