Re: how many records

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От Stuart Woodward
Тема Re: how many records
Дата
Msg-id 20030911101954.F765.WOODWARD@garage.co.jp
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Ответ на Re: how many records  (Simon Willison <cs1spw@bath.ac.uk>)
Ответы Re: how many records  (Bruno Wolff III <bruno@wolff.to>)
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> Bryan Irvine wrote:
> Is there an easy way to count how many records there are?

On Wed, 10 Sep 2003 18:26:30 +0100
Simon Willison <cs1spw@bath.ac.uk> wrote:

> Yes, using count(*):
> select count(*) from tablename;

Is there any performance difference in explicitly naming a column to
count?

i.e select count(id) from tablename;

(I know that a lot of beginners always "select *" even when they don't
need all the information which (I think) is slower than selecting just
what need.)


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