[Benchmark] Add CLI argument num_runs

Previously, the number of runs had to be adjusted by changing the
corresponding global variable in the script.  This can now be done via
CLI argument.  The default is still 5 runs per system, case, and
configuration.

benchmark/Benchmark.py

@@ -26,8 +26,6 @@
 
 BENCHMARK_SYSTEMS: list[str] = ['mutable', 'PostgreSQL', 'DuckDB', 'HyPer']     # List of systems
 
-N_RUNS: int = 5
-
 
 class BenchmarkError(Exception):
     pass
@@ -263,7 +261,8 @@ def perform_experiment(
     system: str,
     info: SimpleNamespace,
     results: Result,
-    output_csv_file: str | None
+    output_csv_file: str | None,
+    num_runs: int
 ) -> None:
     # Experiment parameters
     systems: dict[str, Any] = yml.get('systems', dict())
@@ -279,7 +278,7 @@ def perform_experiment(
 
     # Perform benchmark
     try:
-        connector_result: ConnectorResult = conn.execute(N_RUNS, params)
+        connector_result: ConnectorResult = conn.execute(num_runs, params)
     except connector.ConnectorException as ex:
         tqdm_print(f"\nAn error occurred for {system} while executing {info.path_to_file}: {str(ex)}\n")
         raise BenchmarkError()
@@ -479,7 +478,7 @@ def run_benchmarks(args: argparse.Namespace) -> None:
                     if system == 'mutable':
                         num_experiments_total += 1
                     try:
-                        perform_experiment(yml, conn, system, info, results, output_csv_file)
+                        perform_experiment(yml, conn, system, info, results, output_csv_file, args.num_runs)
                     except BenchmarkError:
                         pass  # nothing to be done
                     else:
@@ -513,6 +512,8 @@ def run_benchmarks(args: argparse.Namespace) -> None:
                         help='Specify file to write measurement in CSV format')
     parser.add_argument('--args', dest='binargs', metavar='ARGS', default=None, action='store',
                         help='provide additional arguments to pass through to the binary')
+    parser.add_argument('-n', '--num-runs', dest='num_runs', metavar='RUNS', default=5, action='store', type=int,
+                        help='specify the number of runs per system, configuration, and case')
     parser.add_argument('-v', '--verbose', help='verbose output', dest='verbose', default=False, action='store_true')
     parser.add_argument('--pgsql', dest='pgsql', default=False, action='store_true',
                         help='create a .pgsql file with instructions to insert measurement results into a PostgreSQL '