diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 30e8d2a..de46dbe 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -142,6 +142,8 @@ int64		latency_limit = 0;
 char	   *tablespace = NULL;
 char	   *index_tablespace = NULL;
 
+bool		single_writer_multi_reader = false;
+
 /*
  * end of configurable parameters
  *********************************************************************/
@@ -1143,6 +1145,15 @@ doCustom(TState *thread, CState *st, instr_time *conn_time, FILE *logfile, AggVa
 top:
 	INSTR_TIME_SET_ZERO(now);
 
+	/* hacked to run single writer, multi-reader test. */
+	if (single_writer_multi_reader)
+	{
+		if (thread->tid == 0)
+			st->use_file = 0;
+		else
+			st->use_file = 1;
+	}
+
 	commands = sql_files[st->use_file];
 
 	/*
@@ -1327,7 +1338,18 @@ top:
 		if (commands[st->state] == NULL)
 		{
 			st->state = 0;
-			st->use_file = (int) getrand(thread, 0, num_files - 1);
+
+			/* hacked to run single writer, multi-reader test. */
+			if (single_writer_multi_reader)
+			{
+				if (thread->tid == 0)
+					st->use_file = 0;
+				else
+					st->use_file = 1;
+			}
+			else
+				st->use_file = (int) getrand(thread, 0, num_files - 1);
+
 			commands = sql_files[st->use_file];
 			st->is_throttled = false;
 
@@ -2619,6 +2641,8 @@ printResults(int ttype, int64 normal_xacts, int nclients,
 
 	if (ttype == 0)
 		s = "TPC-B (sort of)";
+	else if (ttype == 3)
+		s = "SELECT only and Update only";
 	else if (ttype == 2)
 		s = "Update only pgbench_accounts";
 	else if (ttype == 1)
@@ -2850,7 +2874,7 @@ main(int argc, char **argv)
 	state = (CState *) pg_malloc(sizeof(CState));
 	memset(state, 0, sizeof(CState));
 
-	while ((c = getopt_long(argc, argv, "ih:nvp:dqSNc:j:Crs:t:T:U:lf:D:F:M:P:R:L:", long_options, &optindex)) != -1)
+	while ((c = getopt_long(argc, argv, "ih:nvp:dqSNWc:j:Crs:t:T:U:lf:D:F:M:P:R:L:", long_options, &optindex)) != -1)
 	{
 		switch (c)
 		{
@@ -2880,6 +2904,11 @@ main(int argc, char **argv)
 				ttype = 2;
 				benchmarking_option_set = true;
 				break;
+			case 'W':
+				ttype = 3;
+				benchmarking_option_set = true;
+				single_writer_multi_reader = true;
+				break;
 			case 'c':
 				benchmarking_option_set = true;
 				nclients = atoi(optarg);
@@ -3245,7 +3274,7 @@ main(int argc, char **argv)
 		exit(1);
 	}
 
-	if (ttype != 3)
+	if (ttype != 4)
 	{
 		/*
 		 * get the scaling factor that should be same as count(*) from
@@ -3350,6 +3379,14 @@ main(int argc, char **argv)
 			num_files = 1;
 			break;
 
+		case 3:
+			sql_files[0] = process_builtin(simple_update,
+										   "<builtin: simple update>");
+			sql_files[1] = process_builtin(select_only,
+										   "<builtin: select only>");
+			num_files = 2;
+			break;
+
 		default:
 			break;
 	}
@@ -3568,10 +3605,23 @@ threadRun(void *arg)
 	for (i = 0; i < nstate; i++)
 	{
 		CState	   *st = &state[i];
-		Command   **commands = sql_files[st->use_file];
+		Command   **commands;
 		int			prev_ecnt = st->ecnt;
 
-		st->use_file = getrand(thread, 0, num_files - 1);
+		/* hacked to run single writer, multi-reader test. */
+		if (single_writer_multi_reader)
+		{
+			if (thread->tid == 0)
+				st->use_file = 0;
+			else
+				st->use_file = 1;
+		}
+
+		commands = sql_files[st->use_file];
+
+		if (!single_writer_multi_reader)
+			st->use_file = getrand(thread, 0, num_files - 1);
+
 		if (!doCustom(thread, st, &thread->conn_time, logfile, &aggs))
 			remains--;			/* I've aborted */
 
@@ -3599,9 +3649,20 @@ threadRun(void *arg)
 		for (i = 0; i < nstate; i++)
 		{
 			CState	   *st = &state[i];
-			Command   **commands = sql_files[st->use_file];
+			Command   **commands;
 			int			sock;
 
+			/* hacked to run single writer, multi-reader test. */
+			if (single_writer_multi_reader)
+			{
+				if (thread->tid == 0)
+					st->use_file = 0;
+				else
+					st->use_file = 1;
+			}
+
+			commands = sql_files[st->use_file];
+
 			if (st->con == NULL)
 			{
 				continue;
@@ -3705,9 +3766,20 @@ threadRun(void *arg)
 		for (i = 0; i < nstate; i++)
 		{
 			CState	   *st = &state[i];
-			Command   **commands = sql_files[st->use_file];
+			Command   **commands;
 			int			prev_ecnt = st->ecnt;
 
+			/* hacked to run single writer, multi-reader test. */
+			if (single_writer_multi_reader)
+			{
+				if (thread->tid == 0)
+					st->use_file = 0;
+				else
+					st->use_file = 1;
+			}
+
+			commands = sql_files[st->use_file];
+
 			if (st->con && (FD_ISSET(PQsocket(st->con), &input_mask)
 							|| commands[st->state]->type == META_COMMAND))
 			{