RE: DBMS_STATS [resend chomped version]
- From: Jared.Still@xxxxxxxxxxx
- To: oracle-l@xxxxxxxxxxxxx
- Date: Thu, 17 Jun 2004 09:20:35 -0700
Expect changes in execution plans, possibly not for the better.
I had at one time collected histograms for all indexed columns on
a problem database, and was convinced that this shotgun approach
is not really a good idea.
Currently, we aren't collecting any histograms, IIRC.
Jared
Barbara Baker <barbarabbaker@xxxxxxxxx>
Sent by: oracle-l-bounce@xxxxxxxxxxxxx
06/16/2004 03:12 PM
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RE: DBMS_STATS [resend chomped version]
Regarding #1:
(9.2.0.4 Solaris 9)
We have a recommendation from the sw vendor to compute
with histograms using
exec dbms_stats.gather_schema_stats(ownname =>
'SCOTT', estimate_percent =>
dbms_stats.auto_sample_size, method_opt => 'for all
columns size skewonly', cascade => true);
as an initial method to gather the stats. I did a bit
of looking and a bit of testing, and it looks good to
me. Down side: it did take several hours to gather
the initial set of stats.
What are other folks doing with histograms??
Barb
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