[SQL] [MINOR] remove internalRowRDD in DataFrame

Developers have already familiar with `queryExecution.toRDD` as internal row RDD, and we should not add new concept.

Author: Wenchen Fan <cloud0fan@outlook.com>

Closes #7116 from cloud-fan/internal-rdd and squashes the following commits:

24756ca [Wenchen Fan] remove internalRowRDD

4 files changed, 5 insertions, 7 deletions

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala b/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala
index 8fe1f7e34c..caad2da80b 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala
@@ -1469,14 +1469,12 @@ class DataFrame private[sql](
   lazy val rdd: RDD[Row] = {
     // use a local variable to make sure the map closure doesn't capture the whole DataFrame
     val schema = this.schema
-    internalRowRdd.mapPartitions { rows =>
+    queryExecution.toRdd.mapPartitions { rows =>
       val converter = CatalystTypeConverters.createToScalaConverter(schema)
       rows.map(converter(_).asInstanceOf[Row])
     }
   }
 
-  private[sql] def internalRowRdd = queryExecution.executedPlan.execute()
-
   /**
    * Returns the content of the [[DataFrame]] as a [[JavaRDD]] of [[Row]]s.
    * @group rdd
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/stat/FrequentItems.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/stat/FrequentItems.scala
index 3ebbf96090..4e2e2c210d 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/stat/FrequentItems.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/stat/FrequentItems.scala
@@ -90,7 +90,7 @@ private[sql] object FrequentItems extends Logging {
       (name, originalSchema.fields(index).dataType)
     }
 
-    val freqItems = df.select(cols.map(Column(_)) : _*).internalRowRdd.aggregate(countMaps)(
+    val freqItems = df.select(cols.map(Column(_)) : _*).queryExecution.toRdd.aggregate(countMaps)(
       seqOp = (counts, row) => {
         var i = 0
         while (i < numCols) {
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/stat/StatFunctions.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/stat/StatFunctions.scala
index b624ef7e8f..23ddfa9839 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/stat/StatFunctions.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/stat/StatFunctions.scala
@@ -82,7 +82,7 @@ private[sql] object StatFunctions extends Logging {
         s"with dataType ${data.get.dataType} not supported.")
     }
     val columns = cols.map(n => Column(Cast(Column(n).expr, DoubleType)))
-    df.select(columns: _*).internalRowRdd.aggregate(new CovarianceCounter)(
+    df.select(columns: _*).queryExecution.toRdd.aggregate(new CovarianceCounter)(
       seqOp = (counter, row) => {
         counter.add(row.getDouble(0), row.getDouble(1))
       },
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/sources/commands.scala b/sql/core/src/main/scala/org/apache/spark/sql/sources/commands.scala
index 42b51caab5..7214eb0b41 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/sources/commands.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/sources/commands.scala
@@ -154,7 +154,7 @@ private[sql] case class InsertIntoHadoopFsRelation(
     writerContainer.driverSideSetup()
 
     try {
-      df.sqlContext.sparkContext.runJob(df.internalRowRdd, writeRows _)
+      df.sqlContext.sparkContext.runJob(df.queryExecution.toRdd, writeRows _)
       writerContainer.commitJob()
       relation.refresh()
     } catch { case cause: Throwable =>
@@ -220,7 +220,7 @@ private[sql] case class InsertIntoHadoopFsRelation(
     writerContainer.driverSideSetup()
 
     try {
-      df.sqlContext.sparkContext.runJob(df.internalRowRdd, writeRows _)
+      df.sqlContext.sparkContext.runJob(df.queryExecution.toRdd, writeRows _)
       writerContainer.commitJob()
       relation.refresh()
     } catch { case cause: Throwable =>