Re: date_part vs extract

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От Bruce Momjian
Тема Re: date_part vs extract
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Msg-id 200111291914.fATJEPD24332@candle.pha.pa.us
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Ответ на Re: date_part vs extract  (Peter Eisentraut <peter_e@gmx.net>)
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> Markus Bertheau writes:
> 
> > I wonder about the difference between date_part('week', ...) and
> > extract(week from ...) not only but also from a performance point of
> > view. I read extract is standard and date_part is not. Backwards
> > compatibility maybe justifies the existence of date_part. Whats else?
> 
> I think date_part() was adapted from Ingres.  Btw., note that the "week"
> parameter (and most others) aren't standard either.

Yes, from Ingres.  I think Thomas added it.  Both he and I have Ingres
experience.

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