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Re: Need opinions on "Compute Statistics"

From: Ronald Rood <devnull_at_ronr.nl>
Date: 6 Jun 2003 02:00:37 -0700
Message-ID: <67ce88e7.0306060100.4b9e3f13@posting.google.com>


Connor McDonald <connor_mcdonald_at_yahoo.com> wrote in message news:<3EDF1BD3.558D_at_yahoo.com>...
> Sybrand Bakker wrote:
> >
> > On 4 Jun 2003 08:11:31 -0700, aoshell2_at_yahoo.com wrote:
> > To reply remove -verwijderdit from my e-mail address
>
> "The same applies to statistics without histograms."
>
> An excessive number of histograms merely serves to pollute the
> dictionary cache and add to parse times...

And don't forget the fact that when using bind variables the histograms are useless. The plan is only calculated when the qry is parsed for the first time and all re-executions use the same plan, regardless off the values of the bind variables. A datawarehous can't do without histograms. In such an environment it makes no sense to use bind variables.
In 'my' databases I create histograms for those indexes that have a large number of leafblocks per key.

Ronald.



http://ronr.nl/unix-dba Received on Fri Jun 06 2003 - 04:00:37 CDT

Original text of this message

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