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Srinath commented on SPARK-17298: --------------------------------- I've updated the description. Hopefully it is clearer. Note that before this change, even with spark.sql.crossJoin.enabled = false, case 1.a may sometimes NOT throw an error (i.e. execute successfully) depending on the physical plan chosen. With the proposed change, it would always throw an error > Require explicit CROSS join for cartesian products by default > ------------------------------------------------------------- > > Key: SPARK-17298 > URL: https://issues.apache.org/jira/browse/SPARK-17298 > Project: Spark > Issue Type: Story > Components: SQL > Reporter: Srinath > Priority: Minor > > Require the use of CROSS join syntax in SQL (and a new crossJoin DataFrame > API) to specify explicit cartesian products between relations under the > default configuration (spark.sql.crossJoin.enabled = false). > By cartesian product we mean a join between relations R and S where there is > no join condition involving columns from both R and S. > If a cartesian product is detected in the absence of an explicit CROSS join, > an error must be thrown. > Turning on the spark.sql.crossJoin.enabled configuration flag will disable > this check and allow cartesian products without an explicit cross join. -- 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