Qifan Chen has posted comments on this change. ( http://gerrit.cloudera.org:8080/18023 )
Change subject: IMPALA-7942: Add query hints for cardinalities and selectivities ...................................................................... Patch Set 8: "Maybe I can trytrywang this. Here is another question I want to discuss with you. If we support set selectivity hint for compound predicate." Sounds like a good idea. "For 'a=1 /* +SELECTIVITY(0.1) */', this selectivity is definately belong to 'a=1' For 'a=1 and (b=2 /* +SELECTIVITY(0.1) */)', this selectivity is definately belong to 'b=2' For '(a=1 and b=2) /* +SELECTIVITY(0.1) */', this selectivity is definately belong to 'a=1 and b=2'" Yeah, this is about right. "But for these cases: 1. For 'a=1 and b=2 /* +SELECTIVITY(0.1) */' 2. For '(a=1 and b=2 /* +SELECTIVITY(0.1) */)' 3. For '(a=1) and (b=2) /* +SELECTIVITY(0.1) */ Selectivity should belong to which predicate? 'b=2' or 'a=1 and b=2'?" Intuitively, I would think the hint should associate with b=2. Does the parser give the same result? -- 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: 8 Gerrit-Owner: wangsheng <[email protected]> Gerrit-Reviewer: Amogh Margoor <[email protected]> Gerrit-Reviewer: Fucun Chu <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Qifan Chen <[email protected]> Gerrit-Reviewer: Quanlong Huang <[email protected]> Gerrit-Reviewer: Zoltan Borok-Nagy <[email protected]> Gerrit-Reviewer: wangsheng <[email protected]> Gerrit-Comment-Date: Fri, 25 Mar 2022 13:36:28 +0000 Gerrit-HasComments: No
