Re: Explain Plan vs Actual Execution Plan

The really cute thing about the need for global statistics to be reasonable - a few pages further on you'll find the comment that in 8i you can't generate global histograms ! (Fixed in 9i)

Regards

Jonathan Lewis
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The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html

• Original Message ----- From: "Darrell Landrum" <DLANDRUM_at_zalecorp.com> To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com> Sent: 20 March 2003 21:28 Subject: Re: Explain Plan vs Actual Execution Plan
  >
  

> This query was reading data from 5 or 6 partitions of a 54 partition
table.
> That's important information because a couple of weeks ago I was
reading
> the "Oracle 8i Designing and Tuning for Performance" document and
came across this statement:
> "Unless the query predicate narrows the query to a single partition,
the
> optimizer uses the global statistics. Because most queries are not
likely
> to be this restrictive, it is most important to have accurate global
statistics."
> Pretty interesting to think about. It's gather stats global and
Received on Thu Mar 20 2003 - 17:52:53 CST