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Home -> Community -> Usenet -> c.d.o.server -> Re: How is possible that avg_data_blocks_per_key = 0 even with fresh statistics ?
On Dec 13, 7:41 am, hpuxrac <johnbhur..._at_sbcglobal.net> wrote:
> On Dec 10, 9:12 am, "fitzjarr..._at_cox.net" <fitzjarr..._at_cox.net> wrote:
> snip
>
> > > Well this is going off course again but since you brought it back up.
>
> > > No actually what I intended to say was exactly what I said. The
> > > optimizer may or may not come up with bad plans if the statistics say
> > > that a table is empty when it is no longer in that condition.
>
> > Again you assume the table was empty at some point when statistics
> > were collected; according to the OP this was never the case. So why
> > do you insist on pursuing this line of 'logic'?
>
> Read what Mr. Robert Klemme posted ... that's what I responded to
> there. Not from the OP.
>
>
>
> > > I am
> > > confident that test cases can be created either way showing reasonable
> > > and at times unreasonable execution plans.
>
> > Two entirely separate statements. Yes, Jonathan Lewis has generated
> > several such cases but none illustrating the phenomenon you insist on
> > foisting on people. But the optimizer creates these bad plans based
> > upon existing statistics notably due to such things as poorly
> > calculated clustering factors, not zero-valued index 'statistics' for
> > non-zero valued table stats.
>
> > Of course you've not supplied examples for either case.
>
> I don't see that you have either.
Look again, I posted an example proving the contrary to your claim about empty table statistics being retained after the table has been loaded.
>
> > The OP has proven this by posting the TABLE statistics along with the
> > associated INDEX statistics. Maybe you've missed that part of the
> > discussion.
>
> Look at post 24 in the topic thread.
David Fitzjarrell Received on Thu Dec 13 2007 - 07:59:20 CST
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