This is covered in
http://www.datastax.com/dev/blog/whats-new-cassandra-07-secondary-indexes

On Sat, Aug 13, 2011 at 2:49 PM, Jens Hartung <honis@gmx.de> wrote:
> Hi together,
>
> first, I'm using Cassandra Version 0.8.4 and access it via CQL 1.0.3.
>
> When I select data from Cassandra with = in WHERE clause, everything works fine, but when using <= or < in WHERE clause, I always get following Exception:
>
> java.sql.SQLException: No indexed columns present in by-columns clause with "equals" operator
>        at org.apache.cassandra.cql.jdbc.CassandraStatement.executeQuery(CassandraStatement.java:242)
>        at columnfamily.queries.CassandraQueries.singleColumnSelect(CassandraQueries.java:147)
> ...
>
> My select-statement: "SELECT number FROM station WHERE number <= 8210;"
>
> Output of describe keyspace (within cli):
> ColumnFamily: station
>      Key Validation Class: org.apache.cassandra.db.marshal.UTF8Type
>      Default column value validator: org.apache.cassandra.db.marshal.UTF8Type
>      Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
>      Row cache size / save period in seconds: 0.0/0
>      Key cache size / save period in seconds: 200000.0/14400
>      Memtable thresholds: 0.2109375/1440/45 (millions of ops/minutes/MB)
>      GC grace seconds: 864000
>      Compaction min/max thresholds: 4/32
>      Read repair chance: 1.0
>      Replicate on write: true
>      Built indexes: [station.station_number_idx]
>      Column Metadata:
>        [...]
>        Column Name: number
>          Validation Class: org.apache.cassandra.db.marshal.LongType
>          Index Name: station_number_idx
>          Index Type: KEYS
>        [...]
>
> Are the <, <=, >=, > operators not supported at this time?
>
> Greetings
> Jens
> --
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-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support
http://www.datastax.com