Impala Public Jenkins has submitted this change and it was merged. 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/VARIANCE of N rows a divion by N-1 rows is involved. Hence STDDEV_SAMP/VARIANCE for a single row involves a division by 0. This change returns a NULL instead of a 0 when calculating STDDEV_SAMP/VARIANCE for a single row. STDDEV_POP/VARIANCE_POP for single row will still return a 0 since this does not involve a division by 0. This matches the postgres behavior. Change-Id: Ide8af752cd8a2e554a2cd5a1ec948967a80de1fe Reviewed-on: http://gerrit.cloudera.org:8080/5800 Reviewed-by: Matthew Jacobs <[email protected]> Tested-by: Impala Public Jenkins --- M be/src/exprs/aggregate-functions-ir.cc M testdata/workloads/functional-query/queries/QueryTest/aggregation.test 2 files changed, 8 insertions(+), 7 deletions(-) Approvals: Impala Public Jenkins: Verified Matthew Jacobs: Looks good to me, approved -- To view, visit http://gerrit.cloudera.org:8080/5800 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: merged Gerrit-Change-Id: Ide8af752cd8a2e554a2cd5a1ec948967a80de1fe Gerrit-PatchSet: 5 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: anujphadke <[email protected]> Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Matthew Jacobs <[email protected]> Gerrit-Reviewer: anujphadke <[email protected]>
