wangsheng has posted comments on this change. ( http://gerrit.cloudera.org:8080/18023 )
Change subject: IMPALA-7942 (part 2): Add query hints for predicate selectivities ...................................................................... Patch Set 26: (2 comments) http://gerrit.cloudera.org:8080/#/c/18023/23/fe/src/main/java/org/apache/impala/analysis/Expr.java File fe/src/main/java/org/apache/impala/analysis/Expr.java: http://gerrit.cloudera.org:8080/#/c/18023/23/fe/src/main/java/org/apache/impala/analysis/Expr.java@1068 PS23, Line 1068: // and conjunct evaluation. This is not optimal for jitted exprs because it > THis is a generic function to collect conjuncts. The definition should not I extract a method 'allowConjunctsFromChild' here. We add a check for selectivity hint here is due to CompoundPredicate. If we don't check here, selectivity hint for AND CompoundPredicate will always missing, since conjuncts will be it's children, instead of itself. http://gerrit.cloudera.org:8080/#/c/18023/23/fe/src/main/java/org/apache/impala/rewrite/BetweenToCompoundRule.java File fe/src/main/java/org/apache/impala/rewrite/BetweenToCompoundRule.java: http://gerrit.cloudera.org:8080/#/c/18023/23/fe/src/main/java/org/apache/impala/rewrite/BetweenToCompoundRule.java@70 PS23, Line 70: result.setSelectivityHint(bp.getSelectivity()); > What if the compound predicate is not a between predicate? Checks here seem In my opinion, this rule is only used to transform BetweenPredicate to CompoundPredicate, so the input predicate must be BetweenPredicate. If current predicate is not BetweenPredicate, this rule will return directly in line 41. So I think set new created CompoundPredicate's selectivity hint value from BetweenPredicate seems reasonable. I don't understand 'What if the compound predicate is not a between predicate', can you explain this in more detail? -- To view, visit http://gerrit.cloudera.org:8080/18023 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I2776b9bbd878b8a21d9c866b400140a454f59e1b Gerrit-Change-Number: 18023 Gerrit-PatchSet: 26 Gerrit-Owner: wangsheng <[email protected]> Gerrit-Reviewer: Amogh Margoor <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Kurt Deschler <[email protected]> Gerrit-Reviewer: Qifan Chen <[email protected]> Gerrit-Reviewer: Quanlong Huang <[email protected]> Gerrit-Reviewer: Xiang Yang <[email protected]> Gerrit-Reviewer: Zoltan Borok-Nagy <[email protected]> Gerrit-Reviewer: wangsheng <[email protected]> Gerrit-Comment-Date: Fri, 31 Mar 2023 07:49:01 +0000 Gerrit-HasComments: Yes
