Re: Bad performance of SELECT ... where id IN (...)

On Sat, Sep 26, 2009 at 10:59 PM, Craig James
<craig_james(at)emolecules(dot)com> wrote:
>
> If your user_id is always in a narrow range like this, or even in any range
> that is a small fraction of the total, then add a range condition, like
> this:
>
> select * from event where user_id <= 500 and user_id >= 0 and user_id in
> (...)
>
> I did this exact same thing in my application and it worked well.
>
> Craig
>

It is a good idea. But In my application, most of the queries' user_id
are random and difficult to range.
Thanks anyway.

--
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Xia Qingran
qingran(dot)xia(at)gmail(dot)com
Sent from Beijing, 11, China
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