[ https://issues.apache.org/jira/browse/HIVE-9392?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Pengcheng Xiong updated HIVE-9392: ---------------------------------- Attachment: HIVE-9392.5.patch > JoinStatsRule miscalculates join cardinality as incorrect NDV is used due to > column names having duplicated fqColumnName > ------------------------------------------------------------------------------------------------------------------------ > > Key: HIVE-9392 > URL: https://issues.apache.org/jira/browse/HIVE-9392 > Project: Hive > Issue Type: Bug > Components: Physical Optimizer > Affects Versions: 0.14.0 > Reporter: Mostafa Mokhtar > Assignee: Pengcheng Xiong > Priority: Critical > Attachments: HIVE-9392.1.patch, HIVE-9392.2.patch, HIVE-9392.3.patch, > HIVE-9392.4.patch, HIVE-9392.5.patch > > > In JoinStatsRule.process the join column statistics are stored in HashMap > joinedColStats, the key used which is the ColStatistics.fqColName is > duplicated between join column in the same vertex, as a result distinctVals > ends up having duplicated values which negatively affects the join > cardinality estimation. > The duplicate keys are usually named KEY.reducesinkkey0. -- This message was sent by Atlassian JIRA (v6.3.4#6332)