Re: group by

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От Dennis Gearon
Тема Re: group by
Дата
Msg-id 3F7DFDCE.5070509@fireserve.net
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Ответ на group by  (Kathy Zhu <Kathy.Zhu@Sun.COM>)
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When was the last time you vacuumed full?

Kathy Zhu wrote:

>Hi,
>
>I notices a weird thing here.
>
>version 7.2.1
>on Solaris
>
>table "test", has a field "state".
>There are 4 "state" values, 1, 2, 3, 4.
>
>select count(*) from test group by state;
>took 11500 msec
>
>but
>
>select count(*) from test where state = 1;
>select count(*) from test where state = 2;
>select count(*) from test where state = 3;
>select count(*) from test where state = 4;
>total took 626 msec
>
>Why ??
>
>thanks,
>kathy
>
>
>
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