Re: alter index rebuild (NOT ONLINE)

"Norman Dunbar" <Norman_at_RE-MO-VE.BountifulSolutions.co.uk> wrote in message
news:pan.2003.10.31.08.09.06.475108_at_RE-MO-VE.BountifulSolutions.co.uk

> On Thu, 30 Oct 2003 09:24:23 -0800, OakRogbak_erPine_at_yahoo.com Kill the
> 2 trees in email address to reply wrote:
>
> <SNIP>
>
> > I have read many places that it is not a good idea to rebuild them,
> > and I believe that. It is odd though, that Oracle does recommend it:
> > ---
> <SNIP>
>
> Oracle also recommend that you separate tables and indexes in different

Hi, Norman,

As usual, sometimes we go too far in correcting myths and forget to mention those exceptional cases. Let's say the original poster's database is supposed to be read-only but analysts find incorrect data (this does happen sometimes). Updates or deletes are run and the database comes back to read-only. Then it may be worth rebuilding some huge indexes to save disk space and index scan time.

Index rebuild is obviously needed if you want to move its tablespace or after you set it unuseable for a big data change. Tom Kyte says bitmap indexes need more rebuilds. That may be due to Bug 630244 (or "Feature" 630244). Jonathan Lewis says this problem is even more so in ASSM tablespaces.

Yong Huang

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