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Home -> Community -> Usenet -> c.d.o.server -> Re: How many people here rebuid index regularly?
On Oct 6, 3:35 pm, DA Morgan <damor..._at_psoug.org> wrote:
> csn..._at_gmail.com wrote:
>
> >> I realise this would take time, but have you considered a treedump of
> >> the indexes before and after the rebuild:
>
> >> alter session set evnts = 'immediate trace name treedump level <index
> >> object id>';
>
> >> You should see considerable differences in the dump files for a given
> >> index if the rebuild of it improves performance. And those file pairs
> >> with differences would indicate the indexes upon which you should
> >> concentrate your rebuild efforts.
>
> > Comparing index sizes before and after rebuild would probably reveal
> > all there is to know.
>
> Probably not. I wouldn't indicate that a huge waste of time and
> resources had just taken place which is what would be the end-result
> the majority of the time.
> --
> Daniel A. Morgan
> University of Washington
> damor..._at_x.washington.edu (replace x with u to respond)
> Puget Sound Oracle Users Groupwww.psoug.org
Waste of time for majority of cases - yes. In a small number of cases where performance is critical and benefits are tangible, a good DBA should know which ones they are, and what he needs to do, and how often. Received on Sat Oct 06 2007 - 03:04:29 CDT
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