Joe McDonnell has posted comments on this change. ( http://gerrit.cloudera.org:8080/23912 )
Change subject: IMPALA-14436: Calcite planner: Implement single row join optimization ...................................................................... Patch Set 7: (4 comments) http://gerrit.cloudera.org:8080/#/c/23912/7//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/23912/7//COMMIT_MSG@9 PS7, Line 9: The original Impala planner has some optimizations for when there is : a single row produced by the right side. I don't understand what the optimization does. What original Impala test case fails without this? http://gerrit.cloudera.org:8080/#/c/23912/7//COMMIT_MSG@18 PS7, Line 18: This code also changes : a join in tpcds q23a Is this still true? I'm not seeing a difference other than conjuncts vs join conjuncts. http://gerrit.cloudera.org:8080/#/c/23912/7/java/calcite-planner/src/main/java/org/apache/impala/calcite/rel/node/ImpalaJoinRel.java File java/calcite-planner/src/main/java/org/apache/impala/calcite/rel/node/ImpalaJoinRel.java: http://gerrit.cloudera.org:8080/#/c/23912/7/java/calcite-planner/src/main/java/org/apache/impala/calcite/rel/node/ImpalaJoinRel.java@567 PS7, Line 567: case HDFSSCAN: Can there be a limit 1 on HDFSSCAN nodes? http://gerrit.cloudera.org:8080/#/c/23912/7/testdata/workloads/functional-query/queries/QueryTest/calcite.test File testdata/workloads/functional-query/queries/QueryTest/calcite.test: http://gerrit.cloudera.org:8080/#/c/23912/7/testdata/workloads/functional-query/queries/QueryTest/calcite.test@1263 PS7, Line 1263: explain with s as (select id, int_col from functional.alltypestiny where id = 2 limit 1) : select * from functional.alltypessmall b, s where b.int_col > s.int_col If I put this in Impala, I get the same plan whether this is limit 1 or limit 5. This query doesn't rely on anything producing a single row. -- To view, visit http://gerrit.cloudera.org:8080/23912 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I4e5f9be67a775a771c0868ac4407410385e8a755 Gerrit-Change-Number: 23912 Gerrit-PatchSet: 7 Gerrit-Owner: Steve Carlin <[email protected]> Gerrit-Reviewer: Aman Sinha <[email protected]> Gerrit-Reviewer: Fang-Yu Rao <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Joe McDonnell <[email protected]> Gerrit-Reviewer: Michael Smith <[email protected]> Gerrit-Reviewer: Steve Carlin <[email protected]> Gerrit-Comment-Date: Fri, 27 Feb 2026 02:45:24 +0000 Gerrit-HasComments: Yes
