Yin Huai created HIVE-5258: ------------------------------ Summary: Optimize aggregations without Group By followed by a Cross Join Key: HIVE-5258 URL: https://issues.apache.org/jira/browse/HIVE-5258 Project: Hive Issue Type: Improvement Reporter: Yin Huai Assignee: Yin Huai
For example, we should use a single MR job to execute the following query {code:sql} SELECT * FROM (SELECT tmp1.cnt1, tmp2.cnt2 FROM (SELECT count(*) as cnt1 FROM src1 x) tmp1 JOIN (SELECT count(*) as cnt2 FROM src1 y) tmp2) tmp3; {code} The reduce phase should have the reduce side GroupByOperators of tmp1 and tmp2, and the JoinOperator for the cross join. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira