Re: Two efficiency questions - clustering and ints

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От John D. Burger
Тема Re: Two efficiency questions - clustering and ints
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Msg-id 69759D36-7345-4AD7-A63E-7F3457E5CB76@mitre.org
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Ответ на Re: Two efficiency questions - clustering and ints  (Richard Huxton <dev@archonet.com>)
Ответы Re: Two efficiency questions - clustering and ints  (Casey Duncan <casey@pandora.com>)
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Richard Huxton wrote:

>> Should I always cluster the tables?  That is, even if no column
>> jumps out as being involved in most queries, should I pick a
>> likely one and cluster on it?
>
> Well you cluster on an index, and if you don't think the index is
> useful, I'd drop it. If you have an index, clustering isn't
> necessarily going to help you unless you regularly read a series of
> rows in order.

Right, but clustering on that index means an index scan (with that
index) will be faster.  This is uninteresting if the index doesn't
get used, but is there any =downside= to doing it?

Here's a simpler question - for static data, should I always cluster
on the index I think will be used the most?

Thanks.

- John D. Burger
   MITRE


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