RE: Do missing binds prevent creation of baseline?

  • From: Dominic Brooks <dombrooks@xxxxxxxxxxx>
  • To: "rjoralist2@xxxxxxxxxxxxxxxxxxxxx" <rjoralist2@xxxxxxxxxxxxxxxxxxxxx>, "oracle-l@xxxxxxxxxxxxx" <oracle-l@xxxxxxxxxxxxx>
  • Date: Tue, 16 Apr 2013 21:27:54 +0000

> So "plan" in the context of the article's reference to "SQL Plan Baseline"
> is not really the SQL execution plan viewed in V$SQL_PLAN?  And if the
> optimizer is only able to choose between the plans available via baselines,
> wouldn't that absolutely prevent any alteration of the execution path,
> regardless of other changes (e.g. missing index, structure changes, etc.)?
> 
> Poking around the data dictionary, are you referring to the COMP_DATA column
> of SYS.SYSOBJ$DATA?  I am unable to find a reference to a true stored
> plan... :\
Baseline stores the outline hints from v$sql_plan.other_xml.
Plan_id in the underlying sqlobj$* views is the plan_hash_2 seen in 
v$sql_plan.other_xml.

If, at parse time when applying the outline hints from the baseline, the 
plan_hash_2 is not reproduced, the baseline is rejected.


                                          
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