impala-reviews mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "anujphadke (Code Review)" <ger...@cloudera.org>
Subject [Impala-ASF-CR] IMPALA-4738: STDDEV SAMP should return NULL for single record input
Date Wed, 01 Feb 2017 05:51:42 GMT
anujphadke has uploaded a new patch set (#2).

Change subject: IMPALA-4738: STDDEV_SAMP should return NULL for single record input
......................................................................

IMPALA-4738: STDDEV_SAMP should return NULL for single record input

In calculating the STDDEV_SAMP of N rows a divion by N-1 rows is involved.
Hence STDDEV_SAMP for a single row  involves a division by 0. This change
returns a NULL instead of a 0 when calculating STDDEV_SAMP for a single row.
STDDEV_POP for single row will still return a 0 since this does not
involve  a division by 0.

Change-Id: Ide8af752cd8a2e554a2cd5a1ec948967a80de1fe
---
M be/src/exprs/aggregate-functions-ir.cc
M testdata/workloads/functional-query/queries/QueryTest/aggregation.test
2 files changed, 7 insertions(+), 7 deletions(-)


  git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/00/5800/2
-- 
To view, visit http://gerrit.cloudera.org:8080/5800
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-MessageType: newpatchset
Gerrit-Change-Id: Ide8af752cd8a2e554a2cd5a1ec948967a80de1fe
Gerrit-PatchSet: 2
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: anujphadke <aphadke@cloudera.com>
Gerrit-Reviewer: Matthew Jacobs <mj@cloudera.com>
Gerrit-Reviewer: anujphadke <aphadke@cloudera.com>

Mime
View raw message