maropu commented on a change in pull request #32014: URL: https://github.com/apache/spark/pull/32014#discussion_r605628437
########## File path: sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/CostBasedJoinReorder.scala ########## @@ -349,11 +349,14 @@ object JoinReorderDP extends PredicateHelper with Logging { } def betterThan(other: JoinPlan, conf: SQLConf): Boolean = { - val thisCost = BigDecimal(this.planCost.card) * conf.joinReorderCardWeight + - BigDecimal(this.planCost.size) * (1 - conf.joinReorderCardWeight) - val otherCost = BigDecimal(other.planCost.card) * conf.joinReorderCardWeight + - BigDecimal(other.planCost.size) * (1 - conf.joinReorderCardWeight) - thisCost < otherCost + if (other.planCost.card == 0 || other.planCost.size == 0) { + false + } else { Review comment: How about leaving some comments about why we need to use relative values here? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org