spark-instrumented-optimizer/core
Xin Wu 040e46979d [SPARK-10747][SQL] Support NULLS FIRST|LAST clause in ORDER BY
## What changes were proposed in this pull request?
Currently, ORDER BY clause returns nulls value according to sorting order (ASC|DESC), considering null value is always smaller than non-null values.
However, SQL2003 standard support NULLS FIRST or NULLS LAST to allow users to specify whether null values should be returned first or last, regardless of sorting order (ASC|DESC).

This PR is to support this new feature.

## How was this patch tested?
New test cases are added to test NULLS FIRST|LAST for regular select queries and windowing queries.

(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)

Author: Xin Wu <xinwu@us.ibm.com>

Closes #14842 from xwu0226/SPARK-10747.
2016-09-14 21:14:29 +02:00
..
src [SPARK-10747][SQL] Support NULLS FIRST|LAST clause in ORDER BY 2016-09-14 21:14:29 +02:00
pom.xml [SPARK-15487][WEB UI] Spark Master UI to reverse proxy Application and Workers UI 2016-09-08 17:20:20 -07:00