[SPARK-16998] select($"column1", explode($"column2")) is extremely slow - ASF JIRA

Attach files

Attach Screenshot

Voters

Watch issue

Watchers

Create sub-task

Link

Clone

Update Comment Author

Replace String in Comment

Update Comment Visibility

Delete Comments

XML

Word

Printable

JSON

Details

Type: Bug
Status: Resolved
Priority: Major
Resolution: Fixed
Affects Version/s: None
Fix Version/s: 2.2.0
Component/s: SQL
Labels:
None

Description

Using a Dataset containing 10.000 rows, each containing null and an array of 5.000 Ints, I observe the following performance (in local mode):

scala> time(ds.select(explode($"value")).sample(false, 0.0000001, 1).collect)
1.219052 seconds                                                                
res9: Array[org.apache.spark.sql.Row] = Array([3761], [3766], [3196])

scala> time(ds.select($"dummy", explode($"value")).sample(false, 0.0000001, 1).collect)
20.219447 seconds                                                               
res5: Array[org.apache.spark.sql.Row] = Array([null,3761], [null,3766], [null,3196])