hacking contrib/intarray could help you. You need to add function which
return the number of overlapped elements.
Oleg
On Wed, 16 May 2007, John D. Burger wrote:
ABHANG RANE wrote:
I have a array column which has 12 real values in it. Basically these
values represent co-ordinates in 12 dimensions for a substance. My main
need is to find substances similar to a particular compound. Now I can do
by calculating differences with each array in the whole table. But the
table has millions of rows. So I need some kinda higher dimensional index.
Is there any particular reason you're using an array? If every row has all
twelve values, I'd just make them columns. Then I could use a multi-column
index.
I have read about the cube operation in postgre, can it be extended to 12
dimensions or something like that.
I have no experience with CUBE, but I think it's just a kind of summarization
aggregate.
It sounds like you want the Nearest Neighbor(s) of your "particular
compound". You might to read about that:
http://en.wikipedia.org/wiki/Nearest_neighbor_search
- John Burger
G63
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Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: [EMAIL PROTECTED], http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83
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