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  1. Cassandra
  2. CASSANDRA-6644

CQL: Select every nth row within the same partition key

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    Details

    • Type: Improvement
    • Status: Resolved
    • Priority: Normal
    • Resolution: Duplicate
    • Fix Version/s: None
    • Component/s: None
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      Description

      In a time-series schema (like metrics), it is common to create roollups/buckets with datapoints at different rate.
      It would be nice to have a keyword in CQL to be able to retrieve one every nth row (within a single storage engine wide row).

      For example, in the following schema:

      CREATE TABLE metrics (
      ... metric_id varchar,
      ... ts timestamp,
      ... value float,
      ... PRIMARY KEY (metric_id, ts)
      ... );

      The following query, will retrieve 1 in every 3 rows:

      (SKIP keyword or something like that, but don't focus on the syntax)
      SELECT ts, value WHERE metric_id = ? SKIP 2;

      This would be very useful for continuous (and somehow linear) metrics.

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              • Assignee:
                Unassigned
                Reporter:
                jorgebg Jorge Bay
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