address comments

apache · Nov 30, 2016 · 8b697be · 8b697be
1 parent 419fc79
commit 8b697be
Showing 1 changed file with 7 additions and 2 deletions.
diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveUtils.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveUtils.scala
@@ -51,10 +51,15 @@ private[spark] object HiveUtils extends Logging {
     sc
   }
 
-  // The version of hive used internally by Spark SQL.
+  /** The version of hive used internally by Spark SQL. */
   val hiveExecutionVersion: String = "1.2.1"
 
-  // The property key that is used to store the raw hive type string in the metadata of StructField.
+  /**
+   * The property key that is used to store the raw hive type string in the metadata of StructField.
+   * For example, in the case where the Hive type is varchar, the type gets mapped to a string type
+   * in Spark SQL, but we need to preserve the original type in order to invoke the correct object
+   * inspector in Hive.
+   */
   val hiveTypeString: String = "HIVE_TYPE_STRING"
 
   val HIVE_METASTORE_VERSION = SQLConfigBuilder("spark.sql.hive.metastore.version")