wangyum opened a new pull request #33100:
URL: https://github.com/apache/spark/pull/33100
### What changes were proposed in this pull request?
This PR removes order by if the maximum number of rows less than or equal to
1. For example:
```scala
spark.sql("select count(*) from range(1, 10, 2, 2) order by 1 limit
10").explain("cost")
```
Before this pr:
```
== Optimized Logical Plan ==
Sort [count(1)#2L ASC NULLS FIRST], true, Statistics(sizeInBytes=16.0 B)
+- Aggregate [count(1) AS count(1)#2L], Statistics(sizeInBytes=16.0 B,
rowCount=1)
+- Project, Statistics(sizeInBytes=20.0 B)
+- Range (1, 10, step=2, splits=Some(2)), Statistics(sizeInBytes=40.0
B, rowCount=5)
```
After this pr:
```
== Optimized Logical Plan ==
Aggregate [count(1) AS count(1)#2L], Statistics(sizeInBytes=16.0 B,
rowCount=1)
+- Project, Statistics(sizeInBytes=20.0 B)
+- Range (1, 10, step=2, splits=Some(2)), Statistics(sizeInBytes=40.0 B,
rowCount=5)
```
### Why are the changes needed?
Improve query performance.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Unit test.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
