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  1. Cassandra
  2. CASSANDRA-8940

Inconsistent select count and select distinct

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      When performing select count( * ) from ... I expect the results to be consistent over multiple query executions if the table at hand is not written to / deleted from in the mean time. However, in my set-up it is not. The counts returned vary considerable (several percent). The same holds for select distinct partition-key-columns from ....

      I have a table in a keyspace with replication_factor = 1 which is something like:

      CREATE TABLE tbl (
          id frozen<id_type>,
          bucket bigint,
          offset int,
          value double,
          PRIMARY KEY ((id, bucket), offset)
      )
      

      The frozen udt is:

      CREATE TYPE id_type (
          tags map<text, text>
      );
      

      The table contains around 35k rows (I'm not trying to be funny here ...). The consistency level for the queries was ONE.

      Attachments

        1. install_cassandra.sh
          0.7 kB
          Frens Jan Rumph
        2. setup_hosts.sh
          0.3 kB
          Frens Jan Rumph
        3. Vagrantfile
          0.7 kB
          Frens Jan Rumph
        4. 7b74fb00-e935-11e4-b10c-317579db7eb4.csv
          7.73 MB
          Frens Jan Rumph
        5. 8d5899d0-e935-11e4-847b-2d06da75a6cd.csv
          694 kB
          Frens Jan Rumph
        6. 8940.txt
          3 kB
          Benjamin Lerer

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            blerer Benjamin Lerer
            frensjan Frens Jan Rumph
            Benjamin Lerer
            Aleksey Yeschenko
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              Created:
              Updated:
              Resolved: