Uploaded image for project: 'Teiid'
  1. Teiid
  2. TEIID-3743

Multiple Count Distinct Columns Fails for Impala

    Details

      Description

      Teiid Impala translator incorrectly allows multiple count distinct columns, which fails to execute since it is not supported by Impala.

      Per Cloudera documentation:

      By default, Impala only allows a single COUNT(DISTINCT columns) expression in each query.

      To produce the same result as multiple COUNT(DISTINCT) expressions, you can use the following technique for queries involving a single table:

      select v1.c1 result1, v2.c1 result2 from (select count(distinct col1) as c1 from t1) v1 cross join (select count(distinct col2) as c1 from t1) v2;

      The Teiid-Impala translator should ideally rewrite the query as necessary so that the query does not fail executing multiple count distincts against Impala.

        Gliffy Diagrams

          Attachments

            Activity

              People

              • Assignee:
                shawkins Steven Hawkins
                Reporter:
                walla2sl Scott Wallace
              • Votes:
                0 Vote for this issue
                Watchers:
                2 Start watching this issue

                Dates

                • Created:
                  Updated:
                  Resolved: