jonathan, I bench mark iot and single column table with index
. as expected delete and insert are much faster 2 to 3 folds. insert is
about the same.
Ted
In article <936733173.1506.0.nnrp-12.9e984b29_at_news.demon.co.uk>,
"Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote:
> If you are basically thinking about a single column
> table with a Unique index on that single column
> then it is almost certain that you should implement
> the table as an IOT, since
>
> a) The space used will be ca. half that of an indexed heap table
> b) The heap table would not be touch by most queries anyway
>
> An IOT would be particularly useful in 8.1 for this, as the
> inevitable efficiency degradation of an index (assuming random
> insertions of new card numbers) can be eliminated by
> doing an ONLINE rebuild of the table. I have to say that I haven't
> yet done any tests of the performance overheads involved in
> doing such a rebuild on a large IOT though.
>
> --
>
> Jonathan Lewis
> Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk
>
> tedchyn_at_yahoo.com wrote in message <7r3m07$u19$1_at_nnrp1.deja.com>...
> >Sir, what is pro and cons for index only table in terms of
performance ?
> >I have a master credit card number which is unique by itself. Two
> >alternatives are here:
> >1. regular table with card_number field and unique index on card
number
> >and
> >2. index only table with card)number field.
>
>
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Received on Thu Sep 09 1999 - 17:52:06 CDT
