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From Paul Prescod <p...@prescod.net>
Subject Re: How to perform queries on Cassandra?
Date Fri, 09 Apr 2010 23:30:05 GMT
2010/4/9 Onur AKTAS <onur.aktas@live.com>:
> ...
> I'm trying to find out how do you perform queries with calculations on the
> fly without inserting the data as calculated from the beginning.
> Lets say we have latitude and longitude coordinates of all users and we have
>  Distance(from_lat, from_long, to_lat, to_long) function which
> gives distance between lat/longs pairs in kilometers.

I'm not an expert, but I think that it boils down to "MapReduce" and "Hadoop".

I don't think that there's any top-down tutorial on those two words,
you'll have to research yourself starting here:

 * http://en.wikipedia.org/wiki/MapReduce

 * http://hadoop.apache.org/

 * http://wiki.apache.org/cassandra/HadoopSupport

I don't think it is all documented in any one place yet...

 Paul Prescod

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