Marcel Kornacker has posted comments on this change.

Change subject: IMPALA-3063: Separate join inversion from join ordering.
......................................................................


Patch Set 2:

(4 comments)

http://gerrit.cloudera.org:8080/#/c/3846/2//COMMIT_MSG
Commit Message:

Line 7: IMPALA-3063: Separate join inversion from join ordering.
> Correct. Let me explain why it is not only a separation of functionality.
a) please add this explanation to the commit msg

b) follow-on work: a join b and b join a should really be symmetric/the fk/pk 
detection heuristic should work in both directions (having it be symmetric 
means that the inversion logic really can be separated from ordering, aside 
from doing that just for code structuring purposes).


http://gerrit.cloudera.org:8080/#/c/3846/2/testdata/workloads/functional-planner/queries/PlannerTest/outer-joins.test
File testdata/workloads/functional-planner/queries/PlannerTest/outer-joins.test:

Line 814: |  |--07:HASH JOIN [RIGHT OUTER JOIN]
> Good catch. The cardinality estimates are clear: Join 08 should indeed be i
i think we want to improve the existing behavior, no? :)


http://gerrit.cloudera.org:8080/#/c/3846/2/testdata/workloads/functional-planner/queries/PlannerTest/tpch-nested.test
File testdata/workloads/functional-planner/queries/PlannerTest/tpch-nested.test:

Line 1088: |  hash predicates: l_suppkey = s_suppkey, l_partkey = ps_partkey
> We do order them based on cost, but we don't have a tie breaker to get an a
yes, i didn't mean as part of this patch. and this sounds like a ramp-up task 
for someone else.


Line 1777: |  hash predicates: p_partkey = ps_partkey
> Another good catch. The change was only coincidentally caused by this patch
so is that fixed now?


-- 
To view, visit http://gerrit.cloudera.org:8080/3846
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-MessageType: comment
Gerrit-Change-Id: If86db7753fc585bb4c69612745ec0103278888a4
Gerrit-PatchSet: 2
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Alex Behm <[email protected]>
Gerrit-Reviewer: Alex Behm <[email protected]>
Gerrit-Reviewer: Marcel Kornacker <[email protected]>
Gerrit-HasComments: Yes

Reply via email to