add a prune rule for grouping set

Author: adrian-wang

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala

@@ -119,6 +119,10 @@ object ColumnPruning extends Rule[LogicalPlan] {
     case a @ Aggregate(_, _, child) if (child.outputSet -- a.references).nonEmpty =>
       a.copy(child = Project(a.references.toSeq, child))
 
+    case p @ Project(_, Aggregate(ge, ec, child))
+      if (ec.map(_.references).toSet -- p.references).nonEmpty =>
+      Aggregate(ge, ec.filter(e => p.references.contains(e)), child)
+
     // Eliminate unneeded attributes from either side of a Join.
     case Project(projectList, Join(left, right, joinType, condition)) =>
       // Collect the list of all references required either above or to evaluate the condition.