Re: cube operations

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