On Tue, Jun 13, 2006 at 05:23:56PM -0400, Christopher Browne wrote:
> > [3] http://www.intelligententerprise.com/010327/celko_online.jhtml;jsessionid=NDIHEWXGL4TNKQSNDBNSKHSCJUMEKJVN
>
> The sample problem in [3] is one that shows pretty nicely a
> significant SQL weakness; it's very painful to build SQL to do complex
> things surrounding cumulative statistics.
I havn't managed to wrap my brain around them yet, but this seems like
something that SQL WINDOW functions would be able to do. For each row
define the window frame to be all the preceding rows, do a SUM() and
divide that over the total. Or perhaps the PERCENT_RANK() function does
this already, not sure.
Mind you, postgres doesn't support them yet, but it's interesting that
it may be possible at all...
Have a nice day,
--
Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to litigate.