Details
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Improvement
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Status: Resolved
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Minor
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Resolution: Duplicate
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Description
When map-side-aggregation is disabled (hive.map.aggr=false), constant values in aggregation parameters are attached to every map output row. For example, in test case 'count.q' (https://github.com/apache/hive/blob/trunk/ql/src/test/results/clientpositive/count.q.out). For count(1), if hive.map.aggr=false, '1' will be attached to every output row of ReduceSinkOperator.
Attachments
Issue Links
- duplicates
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HIVE-757 Don't send constants from mapper to reducer for Group By queries
- Open