GitHub user dilipbiswal opened a pull request:
https://github.com/apache/spark/pull/21853
[SPARK-23957][SQL] Sorts in subqueries are redundant and can be removed
## What changes were proposed in this pull request?
Thanks to @henryr for the original idea at
https://github.com/apache/spark/pull/21049
Description from the original PR :
Subqueries (at least in SQL) have 'bag of tuples' semantics. Ordering
them is therefore redundant (unless combined with a limit).
This patch removes the top sort operators from the subquery plans.
## How was this patch tested?
Added test cases in SubquerySuite to cover in, exists and scalar subqueries.
Please review http://spark.apache.org/contributing.html before opening a
pull request.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/dilipbiswal/spark SPARK-23957
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/spark/pull/21853.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #21853
----
commit 191c0eb9c12a1ba7ad210e4429feca11df832598
Author: Dilip Biswal <dbiswal@...>
Date: 2018-07-23T18:46:24Z
[SPARK-23957] Sorts in subqueries are redundant and can be removed
----
---
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org
