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From "Thomas Tauber-Marshall (Code Review)" <ger...@cloudera.org>
Subject [Impala-ASF-CR] IMPALA-5120: Default to partitioned join when stats are missing
Date Thu, 04 May 2017 20:57:36 GMT
Thomas Tauber-Marshall has uploaded a new change for review.

  http://gerrit.cloudera.org:8080/6803

Change subject: IMPALA-5120: Default to partitioned join when stats are missing
......................................................................

IMPALA-5120: Default to partitioned join when stats are missing

Previously, we defaulted to broadcast join when stats were
missing, but this can lead to disastrous plans when the
right hand side is actually large.

Its always difficult to make good plans when stats are missing,
but defaulting to partitioned joins should reduce the risk of
disastrous plans.

Testing:
- Added a planner test that joins a table with no stats.

Change-Id: Ie168ecfcd5e7c5d3c60d16926c151f8f134c81e0
---
M fe/src/main/java/org/apache/impala/planner/DistributedPlanner.java
M testdata/workloads/functional-planner/queries/PlannerTest/joins.test
2 files changed, 37 insertions(+), 1 deletion(-)


  git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/03/6803/1
-- 
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Gerrit-MessageType: newchange
Gerrit-Change-Id: Ie168ecfcd5e7c5d3c60d16926c151f8f134c81e0
Gerrit-PatchSet: 1
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Thomas Tauber-Marshall <tmarshall@cloudera.com>

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