Re: Sorted group by
| От | Thom Brown |
|---|---|
| Тема | Re: Sorted group by |
| Дата | |
| Msg-id | AANLkTi=yOngjw2-hhoyQ8YiUzQ7JCztWTTU_G_UWO_fb@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: Sorted group by (Thom Brown <thom@linux.com>) |
| Список | pgsql-performance |
On 10 August 2010 17:06, Thom Brown <thom@linux.com> wrote: > On 10 August 2010 17:03, Matthew Wakeling <matthew@flymine.org> wrote: >> On Tue, 10 Aug 2010, Thomas Kellerer wrote: >>> >>> No. It's built in (8.4) and it's called Windowing functions: >>> http://www.postgresql.org/docs/8.4/static/tutorial-window.html >>> http://www.postgresql.org/docs/8.4/static/functions-window.html >>> >>> SELECT group, last_value(value) over(ORDER BY number) >>> FROM table >> >> I may be mistaken, but as I understand it, a windowing function doesn't >> reduce the number of rows in the results? >> > > I think you are mistaken. The last_value function is a window > function aggregate. Give it a try. > D'oh, no, I'm mistaken. My brain has been malfunctioning today. -- Thom Brown Registered Linux user: #516935
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