object SkewJoin extends Strategy

Author: YanjieGao

sql/core/src/main/scala/org/apache/spark/sql/execution/SparkStrategies.scala

@@ -193,3 +193,15 @@ private[sql] abstract class SparkStrategies extends QueryPlanner[SparkPlan] {
     }
   }
 }
+
+object SkewJoin extends Strategy with PredicateHelper {
+    def apply(plan: LogicalPlan): Seq[SparkPlan] = plan match {
+         // Find inner joins where at least some predicates can be evaluated by matching hash keys
+         // using the HashFilteredJoin pattern.
+      case SkewFilteredJoin(Inner, leftKeys, rightKeys, condition, left, right) =>
+          val hashJoin =
+              execution.SkewJoin(leftKeys, rightKeys, BuildRight, planLater(left), planLater(right), sparkContext)
+          condition.map(Filter(_, hashJoin)).getOrElse(hashJoin) :: Nil
+      case _ => Nil
+  }
+}