Re: killing processes
От | David Kerr |
---|---|
Тема | Re: killing processes |
Дата | |
Msg-id | 20090721174704.GD32936@mr-paradox.net обсуждение исходный текст |
Ответ на | Re: killing processes (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: killing processes
Re: killing processes |
Список | pgsql-general |
On Tue, Jul 21, 2009 at 01:13:18PM -0400, Tom Lane wrote: - David Kerr <dmk@mr-paradox.net> writes: - I tried it on a table with 899991 random values. It took frickin' - forever, but seemed to be willing to respond to cancels anywhere - along the line. I'm not sure why you're seeing differently. Hehe, yeah. For me I let it run 10 min and hit ^C so maybe i just hit it at a bad place. - (The reason it takes forever is that numeric is a variable-width - type, and access into a varwidth array is O(n), so the sorting - step you've got here is O(n^2). It might help to use unnest() - instead of this handmade version of it ...) unnest() is 8.4 only, right? I'm actually probably just going to install R and use the median function from that. (I was hoping to avoid installing all of R) Or maybe i'll try my hand at a perl one and see if that gives ok performance. Thanks! Dave
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