[SPARK-21103][SQL] QueryPlanConstraints should be part of LogicalPlan

Author: rxin

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/QueryPlan.scala

@@ -22,10 +22,7 @@ import org.apache.spark.sql.catalyst.trees.TreeNode
 import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.types.{DataType, StructType}
 
-abstract class QueryPlan[PlanType <: QueryPlan[PlanType]]
-  extends TreeNode[PlanType]
-  with QueryPlanConstraints[PlanType] {
-
+abstract class QueryPlan[PlanType <: QueryPlan[PlanType]] extends TreeNode[PlanType] {
   self: PlanType =>
 
   def conf: SQLConf = SQLConf.get

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/LogicalPlan.scala

@@ -27,7 +27,7 @@ import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.types.StructType
 
 
-abstract class LogicalPlan extends QueryPlan[LogicalPlan] with Logging {
+abstract class LogicalPlan extends QueryPlan[LogicalPlan] with QueryPlanConstraints with Logging {
 
   private var _analyzed: Boolean = false
 

…atalyst/plans/QueryPlanConstraints.scala …plans/logical/QueryPlanConstraints.scalasql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/QueryPlanConstraints.scala renamed to sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/QueryPlanConstraints.scala sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/QueryPlanConstraints.scala renamed to sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/QueryPlanConstraints.scala

@@ -15,12 +15,12 @@
  * limitations under the License.
  */
 
-package org.apache.spark.sql.catalyst.plans
+package org.apache.spark.sql.catalyst.plans.logical
 
 import org.apache.spark.sql.catalyst.expressions._
 
 
-trait QueryPlanConstraints[PlanType <: QueryPlan[PlanType]] { self: QueryPlan[PlanType] =>
+trait QueryPlanConstraints { self: LogicalPlan =>
 
   /**
    * An [[ExpressionSet]] that contains invariants about the rows output by this operator. For
@@ -99,7 +99,8 @@ trait QueryPlanConstraints[PlanType <: QueryPlan[PlanType]] { self: QueryPlan[Pl
   private lazy val aliasMap: AttributeMap[Expression] = AttributeMap(
     expressions.collect {
       case a: Alias => (a.toAttribute, a.child)
-    } ++ children.flatMap(_.asInstanceOf[QueryPlanConstraints[PlanType]].aliasMap))
+    } ++ children.flatMap(_.asInstanceOf[QueryPlanConstraints].aliasMap))
+    // Note: the explicit cast is necessary, since Scala compiler fails to infer the type.
 
   /**
    * Infers an additional set of constraints from a given set of equality constraints.