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  1. Cassandra
  2. CASSANDRA-12910

SASI: calculatePrimary() always returns null

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    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Low
    • Resolution: Fixed
    • Fix Version/s: 3.11.0
    • Component/s: Feature/SASI
    • Labels:
      None
    • Severity:
      Low

      Description

      While investigating performance issues with SASI (https://github.com/criteo/biggraphite/issues/174 if you want to know more) I ended finding calculatePrimary() in QueryController.java which apparently should return the "primary index".

      It lacks documentation, and I'm unsure what the "primary index" should be, but apparently this function never returns one because primaryIndexes.size() is always 0.

      https://github.com/apache/cassandra/blob/81f6c784ce967fadb6ed7f58de1328e713eaf53c/src/java/org/apache/cassandra/index/sasi/plan/QueryController.java#L237

      I'm unsure if the proper fix is checking if the collection is empty or reversing the operator (selecting the index with higher cardinality versus the one with lower cardinality).

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            • Assignee:
              iksaif Corentin Chary
              Reporter:
              iksaif Corentin Chary
              Authors:
              Corentin Chary
              Reviewers:
              Alex Petrov
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              Dates

              • Created:
                Updated:
                Resolved: