Re: Creating Histograms

  • From: Tanel Põder <tanel.poder.003@xxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Sat, 24 Jul 2004 14:29:47 +0300

> I think someone explained you may not always get same plan.  One
> reason is CBO still looks at table HWM.  But it's still worth doing.

CBO doesn't look at table's real HWM when optimizing a query, it uses the
stats from the point in time when they were gathered. When stats (including
system stats), optimizer parameters (including *_area_sizes) and real values
in predicates stay constant, then the execution plan should stay the same
for a given query, unless you encounter some bugs...

Tanel.


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