[SPARK-18973][SQL] Remove SortPartitions and RedistributeData

## What changes were proposed in this pull request?
SortPartitions and RedistributeData logical operators are not actually used and can be removed. Note that we do have a Sort operator (with global flag false) that subsumed SortPartitions.

## How was this patch tested?
Also updated test cases to reflect the removal.

Author: Reynold Xin <rxin@databricks.com>

Closes #16381 from rxin/SPARK-18973.

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala

@@ -1116,7 +1116,7 @@ class Analyzer(
         case p: Sort =>
           failOnOuterReference(p)
           p
-        case p: RedistributeData =>
+        case p: RepartitionByExpression =>
           failOnOuterReference(p)
           p
 

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/UnsupportedOperationChecker.scala

@@ -166,7 +166,7 @@ object UnsupportedOperationChecker {
         case GlobalLimit(_, _) | LocalLimit(_, _) if subPlan.children.forall(_.isStreaming) =>
           throwError("Limits are not supported on streaming DataFrames/Datasets")
 
-        case Sort(_, _, _) | SortPartitions(_, _) if !containsCompleteData(subPlan) =>
+        case Sort(_, _, _) if !containsCompleteData(subPlan) =>
           throwError("Sorting is not supported on streaming DataFrames/Datasets, unless it is on" +
             "aggregated DataFrame/Dataset in Complete output mode")
 

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

@@ -796,7 +796,7 @@ object PushDownPredicate extends Rule[LogicalPlan] with PredicateHelper {
     case _: Distinct => true
     case _: Generate => true
     case _: Pivot => true
-    case _: RedistributeData => true
+    case _: RepartitionByExpression => true
     case _: Repartition => true
     case _: ScriptTransformation => true
     case _: Sort => true

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

@@ -489,7 +489,7 @@ object FoldablePropagation extends Rule[LogicalPlan] {
     case _: AppendColumns => true
     case _: AppendColumnsWithObject => true
     case _: BroadcastHint => true
-    case _: RedistributeData => true
+    case _: RepartitionByExpression => true
     case _: Repartition => true
     case _: Sort => true
     case _: TypedFilter => true

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

@@ -764,6 +764,28 @@ case class Repartition(numPartitions: Int, shuffle: Boolean, child: LogicalPlan)
   override def output: Seq[Attribute] = child.output
 }
 
+/**
+ * This method repartitions data using [[Expression]]s into `numPartitions`, and receives
+ * information about the number of partitions during execution. Used when a specific ordering or
+ * distribution is expected by the consumer of the query result. Use [[Repartition]] for RDD-like
+ * `coalesce` and `repartition`.
+ * If `numPartitions` is not specified, the number of partitions will be the number set by
+ * `spark.sql.shuffle.partitions`.
+ */
+case class RepartitionByExpression(
+    partitionExpressions: Seq[Expression],
+    child: LogicalPlan,
+    numPartitions: Option[Int] = None) extends UnaryNode {
+
+  numPartitions match {
+    case Some(n) => require(n > 0, s"Number of partitions ($n) must be positive.")
+    case None => // Ok
+  }
+
+  override def maxRows: Option[Long] = child.maxRows
+  override def output: Seq[Attribute] = child.output
+}
+
 /**
  * A relation with one row. This is used in "SELECT ..." without a from clause.
  */

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

@@ -1,49 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.spark.sql.catalyst.plans.logical
-
-import org.apache.spark.sql.catalyst.expressions.{Attribute, Expression, SortOrder}
-
-/**
- * Performs a physical redistribution of the data.  Used when the consumer of the query
- * result have expectations about the distribution and ordering of partitioned input data.
- */
-abstract class RedistributeData extends UnaryNode {
-  override def output: Seq[Attribute] = child.output
-}
-
-case class SortPartitions(sortExpressions: Seq[SortOrder], child: LogicalPlan)
-  extends RedistributeData
-
-/**
- * This method repartitions data using [[Expression]]s into `numPartitions`, and receives
- * information about the number of partitions during execution. Used when a specific ordering or
- * distribution is expected by the consumer of the query result. Use [[Repartition]] for RDD-like
- * `coalesce` and `repartition`.
- * If `numPartitions` is not specified, the number of partitions will be the number set by
- * `spark.sql.shuffle.partitions`.
- */
-case class RepartitionByExpression(
-    partitionExpressions: Seq[Expression],
-    child: LogicalPlan,
-    numPartitions: Option[Int] = None) extends RedistributeData {
-  numPartitions match {
-    case Some(n) => require(n > 0, s"Number of partitions ($n) must be positive.")
-    case None => // Ok
-  }
-}

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/UnsupportedOperationsSuite.scala

@@ -213,7 +213,6 @@ class UnsupportedOperationsSuite extends SparkFunSuite {
 
 
   // Other unary operations
-  testUnaryOperatorInStreamingPlan("sort partitions", SortPartitions(Nil, _), expectedMsg = "sort")
   testUnaryOperatorInStreamingPlan(
     "sample", Sample(0.1, 1, true, 1L, _)(), expectedMsg = "sampling")
   testUnaryOperatorInStreamingPlan(

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

@@ -376,10 +376,6 @@ abstract class SparkStrategies extends QueryPlanner[SparkPlan] {
         } else {
           execution.CoalesceExec(numPartitions, planLater(child)) :: Nil
         }
-      case logical.SortPartitions(sortExprs, child) =>
-        // This sort only sorts tuples within a partition. Its requiredDistribution will be
-        // an UnspecifiedDistribution.
-        execution.SortExec(sortExprs, global = false, child = planLater(child)) :: Nil
       case logical.Sort(sortExprs, global, child) =>
         execution.SortExec(sortExprs, global, planLater(child)) :: Nil
       case logical.Project(projectList, child) =>