]
Steven Hawkins resolved TEIID-3743.
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Fix Version/s: 8.12
Resolution: Done
Addressed with the cross join workaround described. The fix will be in 8.12 Final.
Multiple Count Distinct Columns Fails for Impala
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Key: TEIID-3743
URL:
https://issues.jboss.org/browse/TEIID-3743
Project: Teiid
Issue Type: Bug
Components: Misc. Connectors
Affects Versions: 8.11.4
Reporter: Scott Wallace
Assignee: Steven Hawkins
Fix For: 8.12
Teiid Impala translator incorrectly allows multiple count distinct columns, which fails
to execute since it is not supported by Impala.
Per Cloudera documentation:
{quote}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;{quote}
The Teiid-Impala translator should ideally rewrite the query as necessary so that the
query does not fail executing multiple count distincts against Impala.