[ https://issues.apache.org/jira/browse/IMPALA-7528?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Bikramjeet Vig resolved IMPALA-7528. ------------------------------------ Resolution: Fixed Fix Version/s: Impala 3.1.0 > Division by zero when computing cardinalities of many to many joins on NULL > columns > ----------------------------------------------------------------------------------- > > Key: IMPALA-7528 > URL: https://issues.apache.org/jira/browse/IMPALA-7528 > Project: IMPALA > Issue Type: Bug > Components: Frontend > Affects Versions: Impala 2.12.0 > Reporter: Balazs Jeszenszky > Assignee: Bikramjeet Vig > Priority: Critical > Labels: planner > Fix For: Impala 3.1.0 > > > The following: > {code:java} > | F00:PLAN FRAGMENT [RANDOM] hosts=1 instances=1 | > | Per-Host Resources: mem-estimate=33.94MB mem-reservation=1.94MB | > | 02:HASH JOIN [INNER JOIN, BROADCAST] | > | | hash predicates: b.code = a.code | > | | fk/pk conjuncts: none | > | | runtime filters: RF000 <- a.code | > | | mem-estimate=1.94MB mem-reservation=1.94MB spill-buffer=64.00KB | > | | tuple-ids=1,0 row-size=163B cardinality=9223372036854775807 | > <==== Estimation due to overflow. > | | | > | |--03:EXCHANGE [BROADCAST] | > | | | mem-estimate=0B mem-reservation=0B | > | | | tuple-ids=0 row-size=82B cardinality=823 | > | | | | > | | F01:PLAN FRAGMENT [RANDOM] hosts=1 instances=1 | > | | Per-Host Resources: mem-estimate=32.00MB mem-reservation=0B | > | | 00:SCAN HDFS [default.sample_07 a, RANDOM] | > | | partitions=1/1 files=1 size=44.98KB | > | | stats-rows=823 extrapolated-rows=disabled | > | | table stats: rows=823 size=44.98KB | > | | column stats: all | > | | mem-estimate=32.00MB mem-reservation=0B | > | | tuple-ids=0 row-size=82B cardinality=823 | > | | | > | 01:SCAN HDFS [default.sample_08 b, RANDOM] | > | partitions=1/1 files=1 size=44.99KB | > | runtime filters: RF000 -> b.code | > | stats-rows=823 extrapolated-rows=disabled | > | table stats: rows=823 size=44.99KB | > | column stats: all | > | mem-estimate=32.00MB mem-reservation=0B | > | tuple-ids=1 row-size=82B cardinality=823 | > +--------------------------------------------------------------------+ > {code} > is the result of both join columns having 0 as NDV. > https://github.com/cloudera/Impala/blob/cdh5-trunk/fe/src/main/java/org/apache/impala/planner/JoinNode.java#L368 > should handle this more gracefully. > IMPALA-7310 makes it a bit more likely that someone will run into this. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-all-unsubscr...@impala.apache.org For additional commands, e-mail: issues-all-h...@impala.apache.org