[SPARK-17162] Range does not support SQL generation

## What changes were proposed in this pull request?

The range operator previously didn't support SQL generation, which made it not possible to use in views.

## How was this patch tested?

Unit tests.

cc hvanhovell

Author: Eric Liang <ekl@databricks.com>

Closes #14724 from ericl/spark-17162.

2 files changed, 18 insertions, 14 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveTableValuedFunctions.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveTableValuedFunctions.scala
index 7fdf7fa0c0..6b3bb68538 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveTableValuedFunctions.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveTableValuedFunctions.scala
@@ -28,9 +28,6 @@ import org.apache.spark.sql.types.{DataType, IntegerType, LongType}
  * Rule that resolves table-valued function references.
  */
 object ResolveTableValuedFunctions extends Rule[LogicalPlan] {
-  private lazy val defaultParallelism =
-    SparkContext.getOrCreate(new SparkConf(false)).defaultParallelism
-
   /**
    * List of argument names and their types, used to declare a function.
    */
@@ -84,25 +81,25 @@ object ResolveTableValuedFunctions extends Rule[LogicalPlan] {
     "range" -> Map(
       /* range(end) */
       tvf("end" -> LongType) { case Seq(end: Long) =>
-        Range(0, end, 1, defaultParallelism)
+        Range(0, end, 1, None)
       },
 
       /* range(start, end) */
       tvf("start" -> LongType, "end" -> LongType) { case Seq(start: Long, end: Long) =>
-        Range(start, end, 1, defaultParallelism)
+        Range(start, end, 1, None)
       },
 
       /* range(start, end, step) */
       tvf("start" -> LongType, "end" -> LongType, "step" -> LongType) {
         case Seq(start: Long, end: Long, step: Long) =>
-          Range(start, end, step, defaultParallelism)
+          Range(start, end, step, None)
       },
 
       /* range(start, end, step, numPartitions) */
       tvf("start" -> LongType, "end" -> LongType, "step" -> LongType,
           "numPartitions" -> IntegerType) {
         case Seq(start: Long, end: Long, step: Long, numPartitions: Int) =>
-          Range(start, end, step, numPartitions)
+          Range(start, end, step, Some(numPartitions))
       })
   )
 
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/basicLogicalOperators.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/basicLogicalOperators.scala
index af1736e607..010aec7ba1 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/basicLogicalOperators.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/basicLogicalOperators.scala
@@ -422,17 +422,20 @@ case class Sort(
 
 /** Factory for constructing new `Range` nodes. */
 object Range {
-  def apply(start: Long, end: Long, step: Long, numSlices: Int): Range = {
+  def apply(start: Long, end: Long, step: Long, numSlices: Option[Int]): Range = {
     val output = StructType(StructField("id", LongType, nullable = false) :: Nil).toAttributes
     new Range(start, end, step, numSlices, output)
   }
+  def apply(start: Long, end: Long, step: Long, numSlices: Int): Range = {
+    Range(start, end, step, Some(numSlices))
+  }
 }
 
 case class Range(
     start: Long,
     end: Long,
     step: Long,
-    numSlices: Int,
+    numSlices: Option[Int],
     output: Seq[Attribute])
   extends LeafNode with MultiInstanceRelation {
 
@@ -449,6 +452,14 @@ case class Range(
     }
   }
 
+  def toSQL(): String = {
+    if (numSlices.isDefined) {
+      s"SELECT id AS `${output.head.name}` FROM range($start, $end, $step, ${numSlices.get})"
+    } else {
+      s"SELECT id AS `${output.head.name}` FROM range($start, $end, $step)"
+    }
+  }
+
   override def newInstance(): Range = copy(output = output.map(_.newInstance()))
 
   override lazy val statistics: Statistics = {
@@ -457,11 +468,7 @@ case class Range(
   }
 
   override def simpleString: String = {
-    if (step == 1) {
-      s"Range ($start, $end, splits=$numSlices)"
-    } else {
-      s"Range ($start, $end, step=$step, splits=$numSlices)"
-    }
+    s"Range ($start, $end, step=$step, splits=$numSlices)"
   }
 }