Re: AW: What does trace event 38022? (Bug 6405967)

  • From: Greg Rahn <greg@xxxxxxxxxxxxxxxxxx>
  • To: oracle-l <oracle-l@xxxxxxxxxxxxx>
  • Date: Sat, 28 Mar 2009 20:59:34 -0700

On Fri, Mar 27, 2009 at 9:54 AM, Bobak, Mark <Mark.Bobak@xxxxxxxxxxxx>wrote:

> You mention that _COMPLEX_VIEW_MERGING=false also fixes the problem.  I
> suspect that setting the event is a more "fine-grained" solution.  In other
> words, setting the _COMPLEX_VIEW_MERGING parameter disables all complex view
> merging, whereas setting event 38022 only disables "distinct sort
> elimination at subquery unnest", which I suspect is just one small aspect of
> complex view merging.
>
> Of course, this stuff is not documented, so, that's pure speculation on my
> part, and could be totally wrong....
>


This is correct.  Frequently developers use events to activate/deactivate
parts of the code just for cases like this - when bugs exist.  This gives a
finer granularity of control than hidden parameters.

-- 
Regards,
Greg Rahn
http://structureddata.org

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