Re: randomized order in select?

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От Bruno Wolff III
Тема Re: randomized order in select?
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Msg-id 20040310190250.GA6629@wolff.to
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Ответ на randomized order in select?  (Enver ALTIN <enver.altin@frontsite.com.tr>)
Ответы Re: randomized order in select?
Re: randomized order in select?
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On Wed, Mar 10, 2004 at 18:48:17 +0200, Enver ALTIN <enver.altin@frontsite.com.tr> wrote:
> 
> collect an ID list, choose one randomly and retrieve it. I wish I could
> do something like:
> 
>     select tiptext from tips order by random limit 1
> 
> in PostgreSQL.

You can but it won't be very efficient (for large tables) as it will generate
a random ordering for the whole table, probably do a sort and then return the
first record.  The only thing different you need to do is add () after random:
select tiptext from tips order by random() limit 1

If the number of tips isn't very large doing the above is probably best.


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