Hello Impala Public Jenkins,

I'd like you to reexamine a change. Please visit

    http://gerrit.cloudera.org:8080/17821

to look at the new patch set (#6).

Change subject: WIP IMPALA-2581: LIMIT can be propagated down into some 
aggregations
......................................................................

WIP IMPALA-2581: LIMIT can be propagated down into some aggregations

This patch contains 2 parts:
1. In some cases,  push down limit to pre-aggregation
     a) aggregation node has no aggregate function
     b) aggregation node has no predicate
2. finish aggregation when number of unique keys of hash table has
exceeded the limit.

Queries like

SELECT DISTINCT f FROM t LIMIT n

Can pass the LIMIT all the way down to the pre-aggregation, which
leads to a nearly unbounded speedup on these queries in large tables
when n is low.

Change-Id: I930a6cb203615acfc03f23118d1bc1f0ea360995
---
M be/src/exec/aggregation-node-base.cc
M be/src/exec/aggregation-node-base.h
M be/src/exec/aggregation-node.cc
M be/src/exec/aggregator.h
M be/src/exec/grouping-aggregator.cc
M be/src/exec/grouping-aggregator.h
M be/src/exec/non-grouping-aggregator.h
M be/src/exec/streaming-aggregation-node.cc
M fe/src/main/java/org/apache/impala/planner/DistributedPlanner.java
M 
testdata/workloads/functional-planner/queries/PlannerTest/resource-requirements.test
M 
testdata/workloads/functional-planner/queries/PlannerTest/setoperation-rewrite.test
M 
testdata/workloads/functional-planner/queries/PlannerTest/subquery-rewrite.test
M testdata/workloads/functional-planner/queries/PlannerTest/tpcds/tpcds-q06.test
M testdata/workloads/functional-planner/queries/PlannerTest/tpcds/tpcds-q54.test
M testdata/workloads/functional-query/queries/QueryTest/spilling.test
M testdata/workloads/targeted-perf/queries/aggregation.test
16 files changed, 127 insertions(+), 23 deletions(-)


  git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/21/17821/6
--
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I930a6cb203615acfc03f23118d1bc1f0ea360995
Gerrit-Change-Number: 17821
Gerrit-PatchSet: 6
Gerrit-Owner: liuyao <liu...@sensorsdata.cn>
Gerrit-Reviewer: Impala Public Jenkins <impala-public-jenk...@cloudera.com>

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