Re: How many people here rebuid index regularly?

In article <Y1hNi.7131$DF2.4804_at_trndny09>, "charlie cs" <charliecs (nospam)@hotmail.com> says...
> 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
>
 

We do rebuild indexes, because it was measured to improve performance on our system (9i).

See the thread "Proving or Debunking the need for rebuilding" in this group for a report...

http://groups.google.be/group/comp.databases.oracle.server/browse_thread /thread/9579b57c3434d990/9e32aa3cf9282f81? hl=fr&lnk=gst&q=+Proving+or+Debunking+the+need+for+rebuilding&rnum=1# 9e32aa3cf9282f81

• Raoul