Re: optimizer question

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От Bruce Momjian
Тема Re: optimizer question
Дата
Msg-id 200110112117.f9BLH4N14100@candle.pha.pa.us
обсуждение исходный текст
Ответ на Re: optimizer question  (Tom Lane <tgl@sss.pgh.pa.us>)
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> "Reinoud van Leeuwen" <reinoud@xs4all.nl> writes:
> > I have a table that contains almost 8 milion rows. The primary key is a 
> > sequence, so the index should have a good distribution. Why does the 
> > optimizer refuse to use the index for getting the maximum value?
> 
> The optimizer has no idea that max() has anything to do with indexes.
> You could try something like
> 
>     select * from tab order by foo desc limit 1;

Can we consider doing this optimization automatically?

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