Re: optimizer question
| 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>) |
| Список | pgsql-hackers |
> "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? -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026
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