>

val result = tableA.join(tableB, $"a.id" === $"b.id").groupBy().count()
result.explain(true)
== Parsed Logical Plan ==
Aggregate [count(1) AS count#550L]
+- Join Inner, (id#201L = id#205L)
   :- SubqueryAlias a
   :  +- Range (0, 100000000, splits=3)
   +- SubqueryAlias b
      +- Range (0, 100000000, splits=3)

== Analyzed Logical Plan ==
count: bigint
Aggregate [count(1) AS count#550L]
+- Join Inner, (id#201L = id#205L)
   :- SubqueryAlias a
   :  +- Range (0, 100000000, splits=3)
   +- SubqueryAlias b
      +- Range (0, 100000000, splits=3)

== Optimized Logical Plan ==
Aggregate [count(1) AS count#550L]
+- Project
   +- Join Inner, (id#201L = id#205L)