RE: CBO - hash join vs nested loops

 Laimutis,

Jonathan was talking about SYSTEM statistics. Look up DBMS_STATS.GATHER_SYSTEM_STATS procedure in Oracle docs.

Igor

-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Laimutis Nedzinskas
Sent: Monday, December 05, 2005 10:54 AM To: oracle-l_at_freelists.org
Subject: RE: CBO - hash join vs nested loops

From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Jonathan Lewis "
The first STRATEGIC step is to get the system statistics set so that the optimizer has a truthful image about the time cost of multiblock reads, and the CPU cost of doing tablescans.
"

Can you elaborate a bit more what can be considered for this truthful image apart from the straightforward "compute all for all cascade all"? The only thing left seems to be the histograms which, yes, opens a lot possibilities.

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