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Home -> Community -> Usenet -> c.d.o.server -> Re: Influence of index structure to insert performance
"Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote:
> It is possible for the performance on insertions
> to be affected by column ordering in indexes, but
> in many cases the effect is likely to be something
> that gets lost in the general "noise" level of activity.
>
> To demonstrate the concept:
> Imagine you have a high volume insert
> (sydate, sequence_number, random_value)
>
> If your index is in the same column order then
> as you insert a row into the table, its insertion point
> in the index will (usually) be in the same index leaf
> block as last time - with the occasional fill, change
> of leaf block, and insertion into a branch block.
> This will maximise the benefit you can get from
> buffering and pinning.
On the other hand, if you have multiple processes running this insert statement it might also maximize the contention you get from pinning.
Xho
-- -------------------- http://NewsReader.Com/ -------------------- What's that joke about one-handed economists?Received on Fri Feb 17 2006 - 11:40:05 CST