[ https://issues.apache.org/jira/browse/DRILL-4743?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Zelaine Fong updated DRILL-4743: -------------------------------- Labels: doc-impacting (was: ) > HashJoin's not fully parallelized in query plan > ----------------------------------------------- > > Key: DRILL-4743 > URL: https://issues.apache.org/jira/browse/DRILL-4743 > Project: Apache Drill > Issue Type: Bug > Affects Versions: 1.5.0 > Reporter: Gautam Kumar Parai > Assignee: Gautam Kumar Parai > Labels: doc-impacting > > The underlying problem is filter selectivity under-estimate for a query with > complicated predicates e.g. deeply nested and/or predicates. This leads to > under parallelization of the major fragment doing the join. > To really resolve this problem we need table/column statistics to correctly > estimate the selectivity. However, in the absence of statistics OR even when > existing statistics are insufficient to get a correct estimate of selectivity > this will serve as a workaround. -- This message was sent by Atlassian JIRA (v6.3.4#6332)