Re: select/update performance?

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От Rob Fielding
Тема Re: select/update performance?
Дата
Msg-id 3FA8C602.5030005@dsvr.net
обсуждение исходный текст
Ответ на select/update performance?  (Bjørn T Johansen <btj@havleik.no>)
Ответы Re: select/update performance?  (Bjørn T Johansen <btj@havleik.no>)
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Bjørn T Johansen wrote:
> I need to maintain a manually counter for an id-field, but I can do this
> two ways. Either make a counter table (which means one select and one
> update) or just selecting the largest id from existing table and
> increment by one (just one select + one table lock). Which one is
> fastest?

Is would be better to create a SEQUENCE and simply call nextval on it.
Then you are assured that you'll get a unique sequence when working in a
concurrent environment.

It would also be guaranteed faster than interrogating tables.

Hope this helps,

--

Rob Fielding
Development
Designer Servers Ltd


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