Tim Armstrong has posted comments on this change.

Change subject: IMPALA-2502: don't redundantly repartition grouping aggregations
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Patch Set 7:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/2414/7/testdata/workloads/functional-planner/queries/PlannerTest/aggregation.test
File testdata/workloads/functional-planner/queries/PlannerTest/aggregation.test:

Line 1066: select straight_join coalesce(l_orderkey, 123), count(*)
> Can you explain why we still have an exchange in both example? Just trying 
I added some logging. In the second query it's comparing:

    SlotRef{type=BIGINT, id=2} vs FunctionCallExpr{name=coalesce, isStar=false, 
isDistinct=false, SlotRef{path=l_orderkey, type=BIGINT, id=0} 
NumericLiteral{value=123, type=BIGINT}}

    explain select straight_join ifnull(o_orderkey, 20), count(*)
    from tpch_parquet.lineitem
    join [shuffle] tpch_parquet.orders on coalesce(l_orderkey,123) = 
ifnull(o_orderkey, 20)
   group by 1;

I guess it's not inferring that the output slot corresponding to the grouping 
expr of the aggregation and the function call in the join are in the same 
equivalence class?


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Gerrit-MessageType: comment
Gerrit-Change-Id: Iffdcfd3629b8a69bd23915e1adba3b8323cbbaef
Gerrit-PatchSet: 7
Gerrit-Project: Impala
Gerrit-Branch: cdh5-trunk
Gerrit-Owner: Tim Armstrong <[email protected]>
Gerrit-Reviewer: Alex Behm <[email protected]>
Gerrit-Reviewer: Marcel Kornacker <[email protected]>
Gerrit-Reviewer: Tim Armstrong <[email protected]>
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