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  1. Hive
  2. HIVE-28082

HiveAggregateReduceFunctionsRule could generate an inconsistent result

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    Description

      HiveAggregateReduceFunctionsRule translates AVG, STDDEV_POP, STDDEV_SAMP, VAR_POP, and VAR_SAMP. Those UDFs accept string types and try to decode them as floating point values. It is possible that undecodable values exist.

      We found that it could cause inconsistent behaviors with or without CBO.

      0: jdbc:hive2://hive-hiveserver2:10000/defaul> SELECT AVG('text');
...
+------+
| _c0  |
+------+
| 0.0  |
+------+
1 row selected (18.229 seconds)
0: jdbc:hive2://hive-hiveserver2:10000/defaul> set hive.cbo.enable=false;
No rows affected (0.013 seconds)
0: jdbc:hive2://hive-hiveserver2:10000/defaul> SELECT AVG('text');
...
+-------+
|  _c0  |
+-------+
| NULL  |
+-------+

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          is related to

          Improvement - An improvement or enhancement to an existing feature or task. HIVE-28302 Let SUM UDF return NULL when all rows have non-numeric texts

          • Major - Major loss of function.
          • Resolved
          links to

          Web Link GitHub Pull Request #5091

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              okumin Shohei Okumiya
              okumin Shohei Okumiya
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                Created:
                Updated:
                Resolved: