Re: Query with LIMIT but as random result set?

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От Adrian Klaver
Тема Re: Query with LIMIT but as random result set?
Дата
Msg-id 50EC3AD9.1030902@gmail.com
обсуждение исходный текст
Ответ на Query with LIMIT but as random result set?  (Stefan Keller <sfkeller@gmail.com>)
Список pgsql-general
On 01/08/2013 07:20 AM, Stefan Keller wrote:
> Hi
>
> I have a query like this
>
>    SELECT ST_AsText(way) geom, name AS label
>    FROM osm_point
>    LIMIT 10;
>
> When I repeatedly do this, the result set will be always the same.
> I have observed this only empirically and I know that the ordering of
> the result set is undefined without ORDER BY.
> There are two indexes involved, one geospatial for way and one for name.
>
> My question is: Does someone have an idea on how to randomize the
> result set on every consecutive query?
> And as an option the (limited) resultset should be spatially
> distributed (not clustered).


SELECT ST_AsText(way) geom, name AS label
     FROM osm_point ORDER BY random()
     LIMIT 10;

>
> Yours, Stefan
>
>


--
Adrian Klaver
adrian.klaver@gmail.com


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