From 29d8a5c6c22202cdf7d6cc44f1d6cbeca5946918 Mon Sep 17 00:00:00 2001
From: Narine Kokhlikyan <narine@slice.com>
Date: Tue, 21 Jun 2016 01:12:11 +0300
Subject: [PATCH 1/2] Fixed duplicated documentation problem + separated
 documentation for dapply and dapplyCollect

---
 R/pkg/R/DataFrame.R | 4 +++-
 R/pkg/R/generics.R  | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/R/pkg/R/DataFrame.R b/R/pkg/R/DataFrame.R
index 0ff350d44d4b3..1170e65d31a51 100644
--- a/R/pkg/R/DataFrame.R
+++ b/R/pkg/R/DataFrame.R
@@ -1186,6 +1186,7 @@ dapplyInternal <- function(x, func, schema) {
 #' @family SparkDataFrame functions
 #' @rdname dapply
 #' @name dapply
+#' @seealso dapplyCollect \link{dapplyCollect}
 #' @export
 #' @examples
 #' \dontrun{
@@ -1229,8 +1230,9 @@ setMethod("dapply",
 #'             to each partition will be passed.
 #'             The output of func should be a data.frame.
 #' @family SparkDataFrame functions
-#' @rdname dapply
+#' @rdname dapplyCollect
 #' @name dapplyCollect
+#' @seealso dapply \link{dapply}
 #' @export
 #' @examples
 #' \dontrun{
diff --git a/R/pkg/R/generics.R b/R/pkg/R/generics.R
index 50fc204f998a5..c7cfb11dadaed 100644
--- a/R/pkg/R/generics.R
+++ b/R/pkg/R/generics.R
@@ -450,7 +450,7 @@ setGeneric("covar_pop", function(col1, col2) {standardGeneric("covar_pop") })
 #' @export
 setGeneric("dapply", function(x, func, schema) { standardGeneric("dapply") })
 
-#' @rdname dapply
+#' @rdname dapplyCollect
 #' @export
 setGeneric("dapplyCollect", function(x, func) { standardGeneric("dapplyCollect") })
 

From 02d6bab047c9ae99f3ef154826a362529d0423be Mon Sep 17 00:00:00 2001
From: Narine Kokhlikyan <narine@slice.com>
Date: Sun, 21 Aug 2016 14:10:07 -0700
Subject: [PATCH 2/2] Initial commit

---
 .../apache/spark/sql/RelationalGroupedDataset.scala    | 10 ++++++++++
 .../org/apache/spark/sql/DataFrameAggregateSuite.scala |  3 +++
 2 files changed, 13 insertions(+)

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/RelationalGroupedDataset.scala b/sql/core/src/main/scala/org/apache/spark/sql/RelationalGroupedDataset.scala
index 53d732403f979..25d71aa825018 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/RelationalGroupedDataset.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/RelationalGroupedDataset.scala
@@ -388,6 +388,16 @@ class RelationalGroupedDataset protected[sql](
     pivot(pivotColumn, values.asScala)
   }
 
+  /**
+   * Returns all grouping column names as an array.
+   *
+   * @since 2.1.0
+   */
+  def columns: Array[String] = {
+    val groupingNamedExpressions = groupingExprs.map(alias)
+    groupingNamedExpressions.map(_.name).toArray
+  }
+
   /**
    * Applies the given serialized R function `func` to each group of data. For each unique group,
    * the function will be passed the group key and an iterator that contains all of the elements in
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/DataFrameAggregateSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/DataFrameAggregateSuite.scala
index 69a3b5f278fd8..043822363c35a 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/DataFrameAggregateSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/DataFrameAggregateSuite.scala
@@ -85,6 +85,9 @@ class DataFrameAggregateSuite extends QueryTest with SharedSQLContext {
         Row(new java.math.BigDecimal(3.0), new java.math.BigDecimal(3.0)),
         Row(null, new java.math.BigDecimal(2.0)))
     )
+
+    assert(df1.groupBy("key").columns.sameElements(Array("key")))
+    assert(df1.groupBy("value1", "value2").columns.sameElements(Array("value1", "value2")))
   }
 
   test("SPARK-17124 agg should be ordering preserving") {