cqlsh:tweetsentiment> select * from tweets limit 1; key | data | prediction | timestamp --------------------------------------+--------------------------------------------------------------------------------------------+------------+------------ 02af3941-f21e-4302-8d25-fa989a37a858 | RT @WhiteVsBlackTwt: Obama better hope his daughter ain't got a kik http://t.co/VBQ7jCiPM2 | 4.0 | 1428615131
You can query on the row key, but if you want to query on timestamp, you will get error:
cqlsh:tweetsentiment> select count(*) from tweets where timestamp = '1428614831'; InvalidRequest: code=2200 [Invalid query] message="No secondary indexes on the restricted columns support the provided operators: "
To create a secondary index on timestamp:
cqlsh:tweetsentiment> create index on tweets (timestamp); cqlsh:tweetsentiment> select * from tweets where timestamp = '1428614831' limit 1; key | data | prediction | timestamp --------------------------------------+-------------------------------------------------------------------------+------------+------------ 24cf8862-1391-4864-9cbd-4370526a08ac | RT @vaneedope: @quiinoo_ @ogbhay_ she said you should Kik her sometime | 0.0 | 1428614831
To remove a secondary index:
cqlsh:tweetsentiment> DROP index tweets_timestamp_idx;
DROP index table_column_idx
You can read more:
http://www.datastax.com/dev/blog/whats-new-cassandra-07-secondary-indexes
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