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From Jone Lura <jone.l...@ecc.no>
Subject Help with getting Key range with some column limitations
Date Wed, 18 Aug 2010 18:31:44 GMT
Hi,

We are trying to implement Cassandra to replace one of our biggest SQL tables, and so far
we got it working.

However, for testing I'm using Cassandra 0.6.2, Java and Pelops. (Pelops not that important
for my question) and need suggestions on how to solve a problem retrieving a key range based
on the following.

<Keyspace Name="AIS">
        <ColumnFamily Name="Location"
        ColumnType="Super"
        CompareWith="LongType"
        KeysCached="100%"
        CompareSubcolumnsWith="UTF8Type" />
     ...
    </Keyspace>

The super column got columns for longitude and latitude.

 1. Need to get get max long number for key
 2. The key should also have supercolumns latitude and longitude column intersecting (inside)
with a given boundingbox.

Currently I'm doing like this


        KeyRange keyRange = new KeyRange();
        keyRange.setStart_key("");
        keyRange.setEnd_key("");
        keyRange.setCount(700);

And checking every row in db if it match my bounding box.

But there are a lot more than 700 keys.. and if i set a higher count, the get_range_slice
get a Timeout Exception.

Any ideas?

Best Regards
Jone
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