Re: Proving or Debunking the need for rebuilding

hpuxrac wrote:
> Ben wrote:
> > hpuxrac wrote:
> > > Ben wrote:
> > > > 9.2.0.5 EE AIX5L
> > > >
> > > > Ok so I do believe everyone when they say to quit rebuilding indexes,
> > > > except for certain special cases ( like large purges on tables that
> > > > will never grow again unless the moon is full and the wind blows
> > > > eastward). I do understand that rebuilds can be harmful, BUT how do I
> > > > prove one way or the other?
> > > >
> > > > I want to create matrices on the before and after of an index rebuild.
> > > > How? I don't want to blindly say, "Yes this index needs to be rebuilt"
> > > > I want to show the performance gain or loss from a rebuild. Surely
> > > > there is a way to do this. Do you simply anayze ... validate and
> > > > capture the statistics on the indexes?
> > > >
> > > > Thanks for any ideas and help.
> > >
> > > Check out Tom Kyte's site http://asktom.oracle.com this whole area is
> > > documented extensively there.
> > >
> > > Also Jonathan Lewis's site.
> >
> >
> > I guess I must have looked over the posts, but I have been to Tom's
> > site extensively and Jonathan Lewis's.
> > I've search benchmarking and matrix.. any other good keywords that you
> > obviously know since you're suggesting the site?
>
> Try asktom searching with 2 words ... index rebuild
>
> I will take a quick look at Jonathan's site next

Here is one topic thread from Asktom that discusses the development of a predictive model for determining when to rebuild indexes, with seems to be what the OT is trying to accomplish. Jonathan Lewis weighed in on this discussion.
http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:35336203098853

It is an interesting article if read from start to finish.

Charles Hooper
PC Support Specialist
K&M Machine-Fabricating, Inc. Received on Thu Nov 09 2006 - 14:17:17 CST