At 02:58 PM 8/12/2003 +0200, you wrote:

> > > Index IDX_LOGSHIFTNUM (1)
> > > Depth: 3, leaf buckets: 1149, nodes: 179393
> > > Average data length: 0.00, total dup: 179090, max dup: 1400
> >
> >179090 duplicates out of 179393 nodes is a lot i would drop this index
> >unless there a very specic reason for.
>
>Interesting - I dropped this index, and the result was that it took a sp
>from seconds to minutes ... I will have to investigate why ...

I wouldn't have said this index needed dropping, out of hand. You have no
way of knowing how the dups are distributed, but max dup is relatively
small (less than 0.8 %) suggesting they might be quite even. 1400 isn't a
dreadfully long chain; that still leaves 300 nodes that have single
entries and the rest distributed across (potentially) 88,000 other
nodes...probably less, but maybe still quite selectively. Before ditching
the index, I'd query the table to see just how bad the distribution is.

Helen

>Regards
>
>Tim
>
>
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