[SPARK-30998] ClassCastException when a generator having nested inner generators

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.2, 2.1.3, 2.2.3, 2.3.4, 2.4.5, 3.0.0, 3.1.0
• Fix Version/s: 2.4.6, 3.0.0
• Component/s: SQL
• Assignee: Takeshi Yamamuro
• Reporter: Takeshi Yamamuro
• Created: 01/Mar/20 05:02
• Updated: 03/Mar/20 20:33
• Resolved: 03/Mar/20 14:49

Description

A query below failed in the master/branch-3.0/branch-2.4;

scala> sql("select array(array(1, 2), array(3)) ar").select(explode(explode($"ar"))).show()
20/03/01 13:51:56 ERROR Executor: Exception in task 0.0 in stage 0.0 (TID 0)/ 1]
java.lang.ClassCastException: scala.collection.mutable.ArrayOps$ofRef cannot be cast to org.apache.spark.sql.catalyst.util.ArrayData
	at org.apache.spark.sql.catalyst.expressions.ExplodeBase.eval(generators.scala:313)
	at org.apache.spark.sql.execution.GenerateExec.$anonfun$doExecute$8(GenerateExec.scala:108)
	at scala.collection.Iterator$$anon$11.nextCur(Iterator.scala:484)
	at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:490)
	at scala.collection.Iterator$ConcatIterator.hasNext(Iterator.scala:222)
	at scala.collection.Iterator$$anon$10.hasNext(Iterator.scala:458)
    ...

Issue Links

• links to: GitHub Pull Request #27750
• links to: GitHub Pull Request #27769