Jesus Camacho Rodriguez created HIVE-17041: ----------------------------------------------
Summary: Aggregate elimination with UNIQUE and NOT NULL column Key: HIVE-17041 URL: https://issues.apache.org/jira/browse/HIVE-17041 Project: Hive Issue Type: Sub-task Components: Logical Optimizer Affects Versions: 3.0.0 Reporter: Jesus Camacho Rodriguez If columns are part of a GROUP BY expression and they are UNIQUE and do not accept NULL values, i.e. PK or UK+NOTNULL, the _Aggregate_ operator can be transformed into a Project operator, as each row will end up in a different group. For instance, given that _pk_ is the PRIMARY KEY for the table, the GROUP BY could be removed from grouping columns for following query: {code:sql} SELECT pk, value1 FROM table_1 GROUP BY value1, pk, value2; {code} -- This message was sent by Atlassian JIRA (v6.4.14#64029)