diff --git a/nds-h/nds_h_power.py b/nds-h/nds_h_power.py
index dc1496b..04a2f66 100644
--- a/nds-h/nds_h_power.py
+++ b/nds-h/nds_h_power.py
@@ -186,33 +186,25 @@ def run_query_stream(input_prefix,
                      sub_queries,
                      input_format,
                      output_path=None,
+                     keep_sc=False,
                      output_format="parquet",
                      json_summary_folder=None):
     """run SQL in Spark and record execution time log. The execution time log is saved as a CSV file
     for easy accessibility. TempView Creation time is also recorded.
 
     Args:
-        input_prefix (str): path of input data.
-        property_file (str): path of property file for Spark configuration.
-        query_dict (OrderedDict): ordered dict {query_name: query_content} of all NDS-H queries runnable in Spark
-        time_log_output_path (str): path of the log that contains query execution time, both local
+        :param input_prefix : path of input data or warehouse if input_format is "iceberg" or hive_external=True.
+        :param property_file: property file for Spark configuration.
+        :param query_dict : ordered dict {query_name: query_content} of all TPC-DS queries runnable in Spark
+        :param time_log_output_path : path of the log that contains query execution time, both local
                                     and HDFS path are supported.
-        sub_queries (list): a list of query names to run, if not specified, all queries in the stream
-        input_format (str, optional): type of input data source.
-        output_path (str, optional): path of query output, optional. If not specified, collect()
+        :param input_format : type of input data source.
+        :param output_path : path of query output, optinal. If not specified, collect()
                                      action will be applied to each query. Defaults to None.
-        output_format (str, optional): query output format, choices are csv, orc, parquet. Defaults
-        json_summary_folder (str, optional): path to save JSON summary files for each query.
+        :param output_format : query output format, choices are csv, orc, parquet. Defaults to "parquet".
+        :param keep_sc : Databricks specific to keep the spark context alive. Defaults to False.
+        :param json_summary_folder : path to save JSON summary files for each query.
         to "parquet".
-        :param time_log_output_path:
-        :param sub_queries:
-        :param json_summary_folder:
-        :param output_format:
-        :param output_path:
-        :param input_format:
-        :param input_prefix:
-        :param query_dict:
-        :param property_file:
     """
     queries_reports = []
     execution_time_list = []
@@ -261,8 +253,9 @@ def run_query_stream(input_prefix,
                 summary_prefix = os.path.join(json_summary_folder, '')
             q_report.write_summary(prefix=summary_prefix)
     power_end = int(time.time())
-    power_elapse = int((power_end - power_start) * 1000)
-    spark_session.sparkContext.stop()
+    power_elapse = int((power_end - power_start)*1000)
+    if not keep_sc:
+        spark_session.sparkContext.stop()
     total_time_end = time.time()
     total_elapse = int((total_time_end - total_time_start) * 1000)
     print("====== Power Test Time: {} milliseconds ======".format(power_elapse))
@@ -321,6 +314,11 @@ def load_properties(filename):
                              'absolute. Issue: https://github.com/delta-io/delta/issues/555')
     parser.add_argument('query_stream_file',
                         help='query stream file that contains NDS queries in specific order')
+    parser.add_argument('--keep_sc',
+                        action='store_true',
+                        help='Keep SparkContext alive after running all queries. This is a ' +
+                             'limitation on Databricks runtime environment. User should always '
+                             'attach this flag when running on Databricks.')
     parser.add_argument('time_log',
                         help='path to execution time log, only support local path.',
                         default="")
@@ -355,6 +353,6 @@ def load_properties(filename):
                      args.sub_queries,
                      args.input_format,
                      args.output_prefix,
+                     args.keep_sc,
                      args.output_format,
-                     args.json_summary_folder
-                     )
+                     args.json_summary_folder)
diff --git a/nds/tpcds-gen/pom.xml b/nds/tpcds-gen/pom.xml
index 2c595be..b36ab52 100644
--- a/nds/tpcds-gen/pom.xml
+++ b/nds/tpcds-gen/pom.xml
@@ -77,7 +77,7 @@
           <archive>
             <manifest>
               <addClasspath>true</addClasspath>
-			  <classpathPrefix>lib/</classpathPrefix>
+                          <classpathPrefix>lib/</classpathPrefix>
               <mainClass>org.notmysock.tpcds.GenTable</mainClass>
             </manifest>
           </archive>