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  1. Cassandra
  2. CASSANDRA-5956

Allow filtering on more than 1 clustered component in CQL3



    • Improvement
    • Status: Resolved
    • Low
    • Resolution: Duplicate
    • None
    • Legacy/CQL
    • None


      Right now I am preparing some slides for a talk and tutorial on Cassandra to convince people switching from Thrift to CQL3. However I am facing issues because of the limitation of CQL3 not being able to allow inequality on more than 1 clustered component at a time.

      My example is quite trivial. Let's consider a table to collect daily metrics

      CREATE TABLE daily_metrics
        day int, // day in YYYYMMDD format
        hour int, 
        minute int,
        second int,
        metrics blob, 
        PRIMARY KEY (day, hour, minute, second)

      I should be able to grep all metrics from a range of date

      // select all metrics from 8:30am to 10am

       SELECT metrics FROM daily_metrics WHERE day = 20130828 AND hour >= 8 AND minute >= 30 and hour <= 10

      // select all metrics of the day from 6:30pm

       SELECT metrics FROM daily_metrics WHERE day = 20130828 AND hour >= 18 AND minute >= 30 

      Right now it is just IMPOSSIBLE to do this kind of query with CQL3, which is PITA. We always get the error message

      Bad Request: PRIMARY KEY part minute cannot be restricted (preceding part hour is either not restricted or by a non-EQ relation)

      Of course the example is trivial and I can just model the timestamp with 1 component by sticking hour, minute and second together. However the limitation is still there and indeed there is no technical limitation to allow such a query, except from some effort in CQL3 parsing and validation.

      I know that there is already jira CASSANDRA-4415 which is a really good idea and also CASSANDRA-4851 but the issue raised above is beyond the scope of just paging data.

      People are using more and more compound primary keys to model with Cassandra and they should be able to do slice queries with inequality from all compound components.


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              Unassigned Unassigned
              doanduyhai DuyHai Doan
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