[ https://issues.apache.org/jira/browse/HIVE-16330?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Vineet Garg updated HIVE-16330: ------------------------------- Attachment: HIVE-16330.1.patch > Improve plans for scalar subquery with aggregates > ------------------------------------------------- > > Key: HIVE-16330 > URL: https://issues.apache.org/jira/browse/HIVE-16330 > Project: Hive > Issue Type: Sub-task > Reporter: Vineet Garg > Assignee: Vineet Garg > Attachments: HIVE-16330.1.patch > > > Scalar subquery plans are generated with a count(*) on subquery which is fed > to {{sq_count_check}} UDF. This is to make sure at runtime that there is at > most one row generated by scalar subquery. > We can avoid generating this extra count(*) for scalar subqueries with > aggregates and windowing since such queries are guaranteed to generate at > most one row. e.g. {code:SQL} select * from part where p_size > (select > max(p_size) from part) {code} -- This message was sent by Atlassian JIRA (v6.3.15#6346)