[ https://issues.apache.org/jira/browse/SPARK-11705?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15715675#comment-15715675 ]
Andrew Ray commented on SPARK-11705: ------------------------------------ Above example does not have a cartesian product in Spark 2.0.2 > Eliminate unnecessary Cartesian Join > ------------------------------------ > > Key: SPARK-11705 > URL: https://issues.apache.org/jira/browse/SPARK-11705 > Project: Spark > Issue Type: Improvement > Components: SQL > Reporter: Zhan Zhang > > When we have some queries similar to following (don’t remember the exact > form): > select * from a, b, c, d where a.key1 = c.key1 and b.key2 = c.key2 and c.key3 > = d.key3 > There will be a cartesian join between a and b. But if we just simply change > the table order, for example from a, c, b, d, such cartesian join are > eliminated. > Without such manual tuning, the query will never finish if a, b are big. But > we should not relies on such manual optimization. -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org