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