RE: Histograms
- From: "Yasin Baskan" <yasbs@xxxxxxxxxxxxxx>
- To: <charlottejanehammond@xxxxxxxxx>, "ORACLE-L" <oracle-l@xxxxxxxxxxxxx>
- Date: Tue, 16 Aug 2005 15:11:06 +0300
I do not remember what was the case but i have seen cases where
histograms produced slower execution plans. By removing histograms, the
query went ok. The column data were uniformly distributed. Sorry i do
not have a test case.
My weak memory!
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Charlotte Hammond
Sent: Tuesday, August 16, 2005 2:34 PM
To: ORACLE-L
Subject: Histograms
Hi All,
Can I poll the list on their views on the use of
histograms? I've previously been quite conservative,
only gathering them when we've had a specific case of
bad CBO performance due to skewed data. However I was
interested in this article mentioning a "broad brush"
approach to histogram gathering:
http://www.dba-oracle.com/oracle_tips_all_columns_histograms.htm
Any thoughts to share?
Thank you
Charlotte
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