wangsheng has posted comments on this change. ( http://gerrit.cloudera.org:8080/18829 )
Change subject: IMPALA-7942 (part 1): Add query hints for table cardinalities ...................................................................... Patch Set 5: (3 comments) Thanks for reivew, Quanlong. For other engine: 1. Presto/Trino does not support hint syntax; 2. Spark does not support table row related hint: https://spark.apache.org/docs/latest/sql-ref-syntax-qry-select-hints.html 3. Mysql does not support table row related hint yet: https://dev.mysql.com/doc/refman/8.0/en/optimizer-hints.html It seem that we cannot refer to other engine implement. Maybe we can invite other people to discuss this. http://gerrit.cloudera.org:8080/#/c/18829/4/fe/src/main/java/org/apache/impala/analysis/TableRef.java File fe/src/main/java/org/apache/impala/analysis/TableRef.java: http://gerrit.cloudera.org:8080/#/c/18829/4/fe/src/main/java/org/apache/impala/analysis/TableRef.java@174 PS4, Line 174: corrupt > nit: corrupt Done http://gerrit.cloudera.org:8080/#/c/18829/4/fe/src/main/java/org/apache/impala/planner/HdfsScanNode.java File fe/src/main/java/org/apache/impala/planner/HdfsScanNode.java: http://gerrit.cloudera.org:8080/#/c/18829/4/fe/src/main/java/org/apache/impala/planner/HdfsScanNode.java@1548 PS4, Line 1548: ts. If the table has valid stats, this hint > nit: "If the table has valid stats, this hint will be ignored". Done http://gerrit.cloudera.org:8080/#/c/18829/4/fe/src/main/java/org/apache/impala/planner/HdfsScanNode.java@1548 PS4, Line 1548: has no s > nit: "has no stats" Done -- To view, visit http://gerrit.cloudera.org:8080/18829 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I9f0c773f4e67782a1428db64062f68afbd257af7 Gerrit-Change-Number: 18829 Gerrit-PatchSet: 5 Gerrit-Owner: wangsheng <[email protected]> Gerrit-Reviewer: Aman Sinha <[email protected]> Gerrit-Reviewer: Fang-Yu Rao <[email protected]> Gerrit-Reviewer: Fucun Chu <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Quanlong Huang <[email protected]> Gerrit-Reviewer: wangsheng <[email protected]> Gerrit-Comment-Date: Thu, 08 Sep 2022 12:57:00 +0000 Gerrit-HasComments: Yes
