Re: How many people here rebuid index regularly?

On Oct 4, 10:10 pm, "charlie cs" <charliecs(nospam)@hotmail.com> wrote:
> We are on 9i Oracle.
>
> Search on the internet, some expert say
> "In the overwhelming majority of cases, indexes are extremely well
> self-maintained and index rebuilds are NOT required, ever."
>
> Tom Kytes in his website says
> "The time lag between index rebuilds should be approximately FOREVER.
> Tell me -- why why why WHY are you rebuilding them on a schedule? What is
> the scientific
> basis in reality that is driving you to do this???? "
>
> And some other site says:
> "First rule of thumb is if the index has height greater than four, rebuild
> the index. For most indexes, the height of the index will be quite low,
> i.e. one or two. I have seen an index on a 3 million-row table that had
> height three. An index with height greater than four may need to be rebuilt
> as this might indicate a skewed tree structure. "
>
> Which one is right?
>
> Thanks for your comments
>
> Thanks

Proceed carefully in making any changes to an environment that is running in production.

Take the advice of Tom Kyte and Jonathan Lewis. Read up on the topic and the relevant history.

Beware of the silver bullet type of advice that tells you "when you have to rebuild an index". Most of the time it is un-needed in oracle. Received on Fri Oct 05 2007 - 08:47:15 CDT