[ https://issues.apache.org/jira/browse/DRILL-3130?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Vitalii Diravka resolved DRILL-3130. ------------------------------------ Resolution: Done Fix Version/s: (was: 1.1.0) 1.14.0 Resolved in DRILL-3855 > Project can be pushed below union all / union to improve performance > -------------------------------------------------------------------- > > Key: DRILL-3130 > URL: https://issues.apache.org/jira/browse/DRILL-3130 > Project: Apache Drill > Issue Type: Improvement > Components: Query Planning & Optimization > Reporter: Sean Hsuan-Yi Chu > Assignee: Vitalii Diravka > Priority: Major > Fix For: 1.14.0 > > > A query such as > {code} > Select a from > (select a, b, c, ..., union all select a, b, c, ...) > {code} > will perform Union-All over all the specified columns on the two sides, > despite the fact that only one column is asked for at the end. Ideally, we > should perform ProjectPushDown rule for Union & Union-All to avoid them to > generate results which will be discarded at the end. -- This message was sent by Atlassian JIRA (v7.6.3#76005)