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  1. IMPALA
  2. IMPALA-4738

stddev_samp() returns 0 when it should return NULL

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Critical
    • Resolution: Fixed
    • Affects Version/s: Impala 2.8.0
    • Fix Version/s: Impala 2.9.0
    • Component/s: Backend
    • Labels:

      Description

      Discovered using SF1 TPC-DS and query17.

      PostgreSQL 9.6.1

      grahn=# select stddev_samp(56);
       stddev_samp
      -------------
              NULL
      (1 row)
      

      Impala version 2.7.0-cdh5.10.0 RELEASE (build 1c57740759e175d8810c6790af3c5a60862a0ce9)

      select stddev_samp(56) from (values(1)) t;
      +-----------------+
      | stddev_samp(56) |
      +-----------------+
      | 0               |
      +-----------------+
      

        Activity

        Show
        anujphadke Anuj Phadke added a comment - http://github.mtv.cloudera.com/CDH/Impala/commit/2e0f29c67b07cd0369211b29586f3306b338e62a
        Hide
        jbapple Jim Apple added a comment -

        That commit is not viewable by people who don't work at Cloudera. Here is the code review, which anyone can view:

        https://gerrit.cloudera.org/#/c/5800/

        Show
        jbapple Jim Apple added a comment - That commit is not viewable by people who don't work at Cloudera. Here is the code review, which anyone can view: https://gerrit.cloudera.org/#/c/5800/

          People

          • Assignee:
            anujphadke Anuj Phadke
            Reporter:
            grahn Greg Rahn
          • Votes:
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            Watchers:
            3 Start watching this issue

            Dates

            • Created:
              Updated:
              Resolved:

              Development