address comments.

src/main/scala/com/databricks/spark/sql/perf/Benchmark.scala

@@ -85,6 +85,11 @@ abstract class Benchmark(
     case "on" => sqlContext.setConf("spark.sql.unsafe.enabled", "true")
   }
 
+  val tungsten = Variation("unsafe", Seq("on", "off")) {
+    case "off" => sqlContext.setConf("spark.sql.tungsten.enabled", "false")
+    case "on" => sqlContext.setConf("spark.sql.tungsten.enabled", "true")
+  }
+
   /**
    * Starts an experiment run with a given set of queries.
    * @param queriesToRun a list of queries to be executed.
@@ -335,17 +340,25 @@ abstract class Benchmark(
   trait ExecutionMode
   object ExecutionMode {
     // Benchmark run by collecting queries results  (e.g. rdd.collect())
-    case object CollectResults extends ExecutionMode
+    case object CollectResults extends ExecutionMode {
+      override def toString: String = "collect"
+    }
 
     // Benchmark run by iterating through the queries results rows (e.g. rdd.foreach(row => Unit))
-    case object ForeachResults extends ExecutionMode
+    case object ForeachResults extends ExecutionMode {
+      override def toString: String = "foreach"
+    }
 
     // Benchmark run by saving the output of each query as a parquet file at the specified location
-    case class WriteParquet(location: String) extends ExecutionMode
+    case class WriteParquet(location: String) extends ExecutionMode {
+      override def toString: String = "saveToParquet"
+    }
 
     // Benchmark run by calculating the sum of the hash value of all rows. This is used to check
     // query results.
-    case object HashResults extends ExecutionMode
+    case object HashResults extends ExecutionMode  {
+      override def toString: String = "hash"
+    }
   }
 
   /** Factory object for benchmark queries. */
@@ -454,7 +467,7 @@ abstract class Benchmark(
         // to scala.
         // The executionTime for the entire query includes the time of type conversion
         // from catalyst to scala.
-        var hashSum: Option[Long] = None
+        var result: Option[Long] = None
         val executionTime = benchmarkMs {
           executionMode match {
             case ExecutionMode.CollectResults => dataFrame.rdd.collect()
@@ -464,14 +477,14 @@ abstract class Benchmark(
             case ExecutionMode.HashResults =>
               val columnStr = dataFrame.schema.map(_.name).mkString(",")
               // SELECT SUM(HASH(col1, col2, ...)) FROM (benchmark query)
-              val result =
+              val ret =
                 dataFrame
                   .selectExpr(s"hash($columnStr) as hashValue")
                   .groupBy()
                   .sum("hashValue")
                   .head()
                   .getLong(0)
-              hashSum = Some(result)
+              result = Some(ret)
           }
         }
 
@@ -481,6 +494,7 @@ abstract class Benchmark(
 
         BenchmarkResult(
           name = name,
+          mode = executionMode.toString,
           joinTypes = joinTypes,
           tables = tablesInvolved,
           parsingTime = parsingTime,
@@ -488,13 +502,14 @@ abstract class Benchmark(
           optimizationTime = optimizationTime,
           planningTime = planningTime,
           executionTime = executionTime,
-          hashSum = hashSum,
+          result = result,
           queryExecution = dataFrame.queryExecution.toString,
           breakDown = breakdownResults)
       } catch {
         case e: Exception =>
            BenchmarkResult(
              name = name,
+             mode = executionMode.toString,
              failure = Failure(e.getClass.getName, e.getMessage))
       }
     }

src/main/scala/com/databricks/spark/sql/perf/results.scala

@@ -48,6 +48,7 @@ case class BenchmarkConfiguration(
 /**
  * The result of a query.
  * @param name The name of the query.
+ * @param mode The ExecutionMode of this run.
  * @param joinTypes The type of join operations in the query.
  * @param tables The tables involved in the query.
  * @param parsingTime The time used to parse the query.
@@ -55,11 +56,14 @@ case class BenchmarkConfiguration(
  * @param optimizationTime The time used to optimize the query.
  * @param planningTime The time used to plan the query.
  * @param executionTime The time used to execute the query.
- * @param hashSum sum of hash values calculated from result rows of the query.
+ * @param result the result of this run. It is not necessarily the result of the query.
+ *               For example, it can be the number of rows generated by this query or
+ *               the sum of hash values of rows generated by this query.
  * @param breakDown The breakdown results of the query plan tree.
  */
 case class BenchmarkResult(
     name: String,
+    mode: String,
     joinTypes: Seq[String] = Nil,
     tables: Seq[String] = Nil,
     parsingTime: Option[Double] = None,
@@ -67,7 +71,7 @@ case class BenchmarkResult(
     optimizationTime: Option[Double] = None,
     planningTime: Option[Double] = None,
     executionTime: Option[Double] = None,
-    hashSum: Option[Long] = None,
+    result: Option[Long] = None,
     breakDown: Seq[BreakdownResult] = Nil,
     queryExecution: Option[String] = None,
     failure: Option[Failure] = None)