Parallel worker error

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index ce1b907..88f5f76 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -74,6 +74,7 @@ typedef struct FixedParallelState
 	Oid			temp_namespace_id;
 	Oid			temp_toast_namespace_id;
 	int			sec_context;
+	bool		is_current_user_superuser;
 	PGPROC	   *parallel_master_pgproc;
 	pid_t		parallel_master_pid;
 	BackendId	parallel_master_backend_id;
@@ -197,6 +198,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	Size		segsize = 0;
 	int			i;
 	FixedParallelState *fps;
+	const char *varval;
 	Snapshot	transaction_snapshot = GetTransactionSnapshot();
 	Snapshot	active_snapshot = GetActiveSnapshot();
 
@@ -276,6 +278,11 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->database_id = MyDatabaseId;
 	fps->authenticated_user_id = GetAuthenticatedUserId();
 	GetUserIdAndSecContext(&fps->current_user_id, &fps->sec_context);
+	varval = GetConfigOptionByName("is_superuser", NULL, true);
+	if (varval && strcmp(varval, "on") == 0)
+		fps->is_current_user_superuser = true;
+	else
+		fps->is_current_user_superuser = false;
 	GetTempNamespaceState(&fps->temp_namespace_id,
 						  &fps->temp_toast_namespace_id);
 	fps->parallel_master_pgproc = MyProc;
@@ -1082,6 +1089,12 @@ ParallelWorkerMain(Datum main_arg)
 	/* Restore user ID and security context. */
 	SetUserIdAndSecContext(fps->current_user_id, fps->sec_context);
 
+	/*
+	 * Skip verifying whether session user is allowed to become this role and
+	 * blindly restore the leader's state for current role.
+	 */
+	SetCurrentRoleId(fps->current_user_id, fps->is_current_user_superuser);
+
 	/* Restore temp-namespace state to ensure search path matches leader's. */
 	SetTempNamespaceState(fps->temp_namespace_id,
 						  fps->temp_toast_namespace_id);
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 246fea8..40d8537 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -8986,12 +8986,18 @@ read_nondefault_variables(void)
  * constants; a few, like server_encoding and lc_ctype, are handled specially
  * outside the serialize/restore procedure.  Therefore, SerializeGUCState()
  * never sends these, and RestoreGUCState() never changes them.
+ *
+ * Role is a special variable in the sense that its current value can be an
+ * invalid value and there are multiple ways by which that can happen (like
+ * after setting the role, someone drops it).  So we handle it outside of
+ * serialize/restore machinery.
  */
 static bool
 can_skip_gucvar(struct config_generic *gconf)
 {
 	return gconf->context == PGC_POSTMASTER ||
-		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT;
+		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT ||
+		strcmp(gconf->name, "role") == 0;
 }
 
 /*
@@ -9252,7 +9258,6 @@ SerializeGUCState(Size maxsize, char *start_address)
 	Size		actual_size;
 	Size		bytes_left;
 	int			i;
-	int			i_role = -1;
 
 	/* Reserve space for saving the actual size of the guc state */
 	Assert(maxsize > sizeof(actual_size));
@@ -9260,19 +9265,7 @@ SerializeGUCState(Size maxsize, char *start_address)
 	bytes_left = maxsize - sizeof(actual_size);
 
 	for (i = 0; i < num_guc_variables; i++)
-	{
-		/*
-		 * It's pretty ugly, but we've got to force "role" to be initialized
-		 * after "session_authorization"; otherwise, the latter will override
-		 * the former.
-		 */
-		if (strcmp(guc_variables[i]->name, "role") == 0)
-			i_role = i;
-		else
-			serialize_variable(&curptr, &bytes_left, guc_variables[i]);
-	}
-	if (i_role >= 0)
-		serialize_variable(&curptr, &bytes_left, guc_variables[i_role]);
+		serialize_variable(&curptr, &bytes_left, guc_variables[i]);
 
 	/* Store actual size without assuming alignment of start_address. */
 	actual_size = maxsize - bytes_left - sizeof(actual_size);
diff --git a/src/test/regress/expected/select_parallel.out b/src/test/regress/expected/select_parallel.out
index 2ae600f..b5287ab 100644
--- a/src/test/regress/expected/select_parallel.out
+++ b/src/test/regress/expected/select_parallel.out
@@ -488,6 +488,22 @@ SELECT make_record(x) FROM (SELECT generate_series(1, 5) x) ss ORDER BY x;
 
 ROLLBACK TO SAVEPOINT settings;
 DROP function make_record(n int);
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+NOTICE:  role "regress_parallel_worker" does not exist, skipping
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+ count 
+-------
+ 10000
+(1 row)
+
+reset force_parallel_mode;
+reset role;
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL force_parallel_mode = 1;
diff --git a/src/test/regress/sql/select_parallel.sql b/src/test/regress/sql/select_parallel.sql
index 89fe80a..801df0b 100644
--- a/src/test/regress/sql/select_parallel.sql
+++ b/src/test/regress/sql/select_parallel.sql
@@ -195,6 +195,17 @@ SELECT make_record(x) FROM (SELECT generate_series(1, 5) x) ss ORDER BY x;
 ROLLBACK TO SAVEPOINT settings;
 DROP function make_record(n int);
 
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+reset force_parallel_mode;
+reset role;
+
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL force_parallel_mode = 1;

diff --git a/src/backend/commands/variable.c b/src/backend/commands/variable.c
index 3ed1c56..0d2bbe4 100644
--- a/src/backend/commands/variable.c
+++ b/src/backend/commands/variable.c
@@ -901,12 +901,9 @@ check_role(char **newval, void **extra, GucSource source)
 		ReleaseSysCache(roleTup);
 
 		/*
-		 * Verify that session user is allowed to become this role, but skip
-		 * this in parallel mode, where we must blindly recreate the parallel
-		 * leader's state.
+		 * Verify that session user is allowed to become this role.
 		 */
-		if (!InitializingParallelWorker &&
-			!is_member_of_role(GetSessionUserId(), roleid))
+		if (!is_member_of_role(GetSessionUserId(), roleid))
 		{
 			GUC_check_errcode(ERRCODE_INSUFFICIENT_PRIVILEGE);
 			GUC_check_errmsg("permission denied to set role \"%s\"",

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index ce1b907..248e2db 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -71,9 +71,11 @@ typedef struct FixedParallelState
 	Oid			database_id;
 	Oid			authenticated_user_id;
 	Oid			current_user_id;
+	Oid			outer_user_id;
 	Oid			temp_namespace_id;
 	Oid			temp_toast_namespace_id;
 	int			sec_context;
+	bool		is_current_user_superuser;
 	PGPROC	   *parallel_master_pgproc;
 	pid_t		parallel_master_pid;
 	BackendId	parallel_master_backend_id;
@@ -197,6 +199,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	Size		segsize = 0;
 	int			i;
 	FixedParallelState *fps;
+	const char *varval;
 	Snapshot	transaction_snapshot = GetTransactionSnapshot();
 	Snapshot	active_snapshot = GetActiveSnapshot();
 
@@ -275,7 +278,13 @@ InitializeParallelDSM(ParallelContext *pcxt)
 		shm_toc_allocate(pcxt->toc, sizeof(FixedParallelState));
 	fps->database_id = MyDatabaseId;
 	fps->authenticated_user_id = GetAuthenticatedUserId();
+	fps->outer_user_id = GetCurrentRoleId();
 	GetUserIdAndSecContext(&fps->current_user_id, &fps->sec_context);
+	varval = GetConfigOptionByName("is_superuser", NULL, true);
+	if (varval && strcmp(varval, "on") == 0)
+		fps->is_current_user_superuser = true;
+	else
+		fps->is_current_user_superuser = false;
 	GetTempNamespaceState(&fps->temp_namespace_id,
 						  &fps->temp_toast_namespace_id);
 	fps->parallel_master_pgproc = MyProc;
@@ -1079,6 +1088,13 @@ ParallelWorkerMain(Datum main_arg)
 	 */
 	InvalidateSystemCaches();
 
+	/*
+	 * Restore current role id.  Skip verifying whether session user is
+	 * allowed to become this role and blindly restore the leader's state for
+	 * current role.
+	 */
+	SetCurrentRoleId(fps->outer_user_id, fps->is_current_user_superuser);
+
 	/* Restore user ID and security context. */
 	SetUserIdAndSecContext(fps->current_user_id, fps->sec_context);
 
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 969e80f..e4bed34 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -8986,12 +8986,18 @@ read_nondefault_variables(void)
  * constants; a few, like server_encoding and lc_ctype, are handled specially
  * outside the serialize/restore procedure.  Therefore, SerializeGUCState()
  * never sends these, and RestoreGUCState() never changes them.
+ *
+ * Role is a special variable in the sense that its current value can be an
+ * invalid value and there are multiple ways by which that can happen (like
+ * after setting the role, someone drops it).  So we handle it outside of
+ * serialize/restore machinery.
  */
 static bool
 can_skip_gucvar(struct config_generic *gconf)
 {
 	return gconf->context == PGC_POSTMASTER ||
-		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT;
+		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT ||
+		strcmp(gconf->name, "role") == 0;
 }
 
 /*
@@ -9252,7 +9258,6 @@ SerializeGUCState(Size maxsize, char *start_address)
 	Size		actual_size;
 	Size		bytes_left;
 	int			i;
-	int			i_role = -1;
 
 	/* Reserve space for saving the actual size of the guc state */
 	Assert(maxsize > sizeof(actual_size));
@@ -9260,19 +9265,7 @@ SerializeGUCState(Size maxsize, char *start_address)
 	bytes_left = maxsize - sizeof(actual_size);
 
 	for (i = 0; i < num_guc_variables; i++)
-	{
-		/*
-		 * It's pretty ugly, but we've got to force "role" to be initialized
-		 * after "session_authorization"; otherwise, the latter will override
-		 * the former.
-		 */
-		if (strcmp(guc_variables[i]->name, "role") == 0)
-			i_role = i;
-		else
-			serialize_variable(&curptr, &bytes_left, guc_variables[i]);
-	}
-	if (i_role >= 0)
-		serialize_variable(&curptr, &bytes_left, guc_variables[i_role]);
+		serialize_variable(&curptr, &bytes_left, guc_variables[i]);
 
 	/* Store actual size without assuming alignment of start_address. */
 	actual_size = maxsize - bytes_left - sizeof(actual_size);
diff --git a/src/test/regress/expected/select_parallel.out b/src/test/regress/expected/select_parallel.out
index 2ae600f..b5287ab 100644
--- a/src/test/regress/expected/select_parallel.out
+++ b/src/test/regress/expected/select_parallel.out
@@ -488,6 +488,22 @@ SELECT make_record(x) FROM (SELECT generate_series(1, 5) x) ss ORDER BY x;
 
 ROLLBACK TO SAVEPOINT settings;
 DROP function make_record(n int);
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+NOTICE:  role "regress_parallel_worker" does not exist, skipping
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+ count 
+-------
+ 10000
+(1 row)
+
+reset force_parallel_mode;
+reset role;
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL force_parallel_mode = 1;
diff --git a/src/test/regress/sql/select_parallel.sql b/src/test/regress/sql/select_parallel.sql
index 89fe80a..801df0b 100644
--- a/src/test/regress/sql/select_parallel.sql
+++ b/src/test/regress/sql/select_parallel.sql
@@ -195,6 +195,17 @@ SELECT make_record(x) FROM (SELECT generate_series(1, 5) x) ss ORDER BY x;
 ROLLBACK TO SAVEPOINT settings;
 DROP function make_record(n int);
 
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+reset force_parallel_mode;
+reset role;
+
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL force_parallel_mode = 1;

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index ce1b907..62b287e 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -71,9 +71,11 @@ typedef struct FixedParallelState
 	Oid			database_id;
 	Oid			authenticated_user_id;
 	Oid			current_user_id;
+	Oid			outer_user_id;
 	Oid			temp_namespace_id;
 	Oid			temp_toast_namespace_id;
 	int			sec_context;
+	bool		is_superuser;
 	PGPROC	   *parallel_master_pgproc;
 	pid_t		parallel_master_pid;
 	BackendId	parallel_master_backend_id;
@@ -197,6 +199,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	Size		segsize = 0;
 	int			i;
 	FixedParallelState *fps;
+	const char *is_superuser_var;
 	Snapshot	transaction_snapshot = GetTransactionSnapshot();
 	Snapshot	active_snapshot = GetActiveSnapshot();
 
@@ -275,7 +278,13 @@ InitializeParallelDSM(ParallelContext *pcxt)
 		shm_toc_allocate(pcxt->toc, sizeof(FixedParallelState));
 	fps->database_id = MyDatabaseId;
 	fps->authenticated_user_id = GetAuthenticatedUserId();
+	fps->outer_user_id = GetCurrentRoleId();
 	GetUserIdAndSecContext(&fps->current_user_id, &fps->sec_context);
+	is_superuser_var = GetConfigOptionByName("is_superuser", NULL, true);
+	if (is_superuser_var && strcmp(is_superuser_var, "on") == 0)
+		fps->is_superuser = true;
+	else
+		fps->is_superuser = false;
 	GetTempNamespaceState(&fps->temp_namespace_id,
 						  &fps->temp_toast_namespace_id);
 	fps->parallel_master_pgproc = MyProc;
@@ -1079,6 +1088,13 @@ ParallelWorkerMain(Datum main_arg)
 	 */
 	InvalidateSystemCaches();
 
+	/*
+	 * Restore current role id.  Skip verifying whether session user is
+	 * allowed to become this role and blindly restore the leader's state for
+	 * current role.
+	 */
+	SetCurrentRoleId(fps->outer_user_id, fps->is_superuser);
+
 	/* Restore user ID and security context. */
 	SetUserIdAndSecContext(fps->current_user_id, fps->sec_context);
 
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 969e80f..e4bed34 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -8986,12 +8986,18 @@ read_nondefault_variables(void)
  * constants; a few, like server_encoding and lc_ctype, are handled specially
  * outside the serialize/restore procedure.  Therefore, SerializeGUCState()
  * never sends these, and RestoreGUCState() never changes them.
+ *
+ * Role is a special variable in the sense that its current value can be an
+ * invalid value and there are multiple ways by which that can happen (like
+ * after setting the role, someone drops it).  So we handle it outside of
+ * serialize/restore machinery.
  */
 static bool
 can_skip_gucvar(struct config_generic *gconf)
 {
 	return gconf->context == PGC_POSTMASTER ||
-		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT;
+		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT ||
+		strcmp(gconf->name, "role") == 0;
 }
 
 /*
@@ -9252,7 +9258,6 @@ SerializeGUCState(Size maxsize, char *start_address)
 	Size		actual_size;
 	Size		bytes_left;
 	int			i;
-	int			i_role = -1;
 
 	/* Reserve space for saving the actual size of the guc state */
 	Assert(maxsize > sizeof(actual_size));
@@ -9260,19 +9265,7 @@ SerializeGUCState(Size maxsize, char *start_address)
 	bytes_left = maxsize - sizeof(actual_size);
 
 	for (i = 0; i < num_guc_variables; i++)
-	{
-		/*
-		 * It's pretty ugly, but we've got to force "role" to be initialized
-		 * after "session_authorization"; otherwise, the latter will override
-		 * the former.
-		 */
-		if (strcmp(guc_variables[i]->name, "role") == 0)
-			i_role = i;
-		else
-			serialize_variable(&curptr, &bytes_left, guc_variables[i]);
-	}
-	if (i_role >= 0)
-		serialize_variable(&curptr, &bytes_left, guc_variables[i_role]);
+		serialize_variable(&curptr, &bytes_left, guc_variables[i]);
 
 	/* Store actual size without assuming alignment of start_address. */
 	actual_size = maxsize - bytes_left - sizeof(actual_size);
diff --git a/src/test/regress/expected/select_parallel.out b/src/test/regress/expected/select_parallel.out
index 2ae600f..b5287ab 100644
--- a/src/test/regress/expected/select_parallel.out
+++ b/src/test/regress/expected/select_parallel.out
@@ -488,6 +488,22 @@ SELECT make_record(x) FROM (SELECT generate_series(1, 5) x) ss ORDER BY x;
 
 ROLLBACK TO SAVEPOINT settings;
 DROP function make_record(n int);
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+NOTICE:  role "regress_parallel_worker" does not exist, skipping
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+ count 
+-------
+ 10000
+(1 row)
+
+reset force_parallel_mode;
+reset role;
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL force_parallel_mode = 1;
diff --git a/src/test/regress/sql/select_parallel.sql b/src/test/regress/sql/select_parallel.sql
index 89fe80a..801df0b 100644
--- a/src/test/regress/sql/select_parallel.sql
+++ b/src/test/regress/sql/select_parallel.sql
@@ -195,6 +195,17 @@ SELECT make_record(x) FROM (SELECT generate_series(1, 5) x) ss ORDER BY x;
 ROLLBACK TO SAVEPOINT settings;
 DROP function make_record(n int);
 
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+reset force_parallel_mode;
+reset role;
+
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL force_parallel_mode = 1;

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index ce1b907..e1a6a75 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -71,9 +71,11 @@ typedef struct FixedParallelState
 	Oid			database_id;
 	Oid			authenticated_user_id;
 	Oid			current_user_id;
+	Oid			outer_user_id;
 	Oid			temp_namespace_id;
 	Oid			temp_toast_namespace_id;
 	int			sec_context;
+	bool		is_superuser;
 	PGPROC	   *parallel_master_pgproc;
 	pid_t		parallel_master_pid;
 	BackendId	parallel_master_backend_id;
@@ -275,6 +277,8 @@ InitializeParallelDSM(ParallelContext *pcxt)
 		shm_toc_allocate(pcxt->toc, sizeof(FixedParallelState));
 	fps->database_id = MyDatabaseId;
 	fps->authenticated_user_id = GetAuthenticatedUserId();
+	fps->outer_user_id = GetCurrentRoleId();
+	fps->is_superuser = session_auth_is_superuser;
 	GetUserIdAndSecContext(&fps->current_user_id, &fps->sec_context);
 	GetTempNamespaceState(&fps->temp_namespace_id,
 						  &fps->temp_toast_namespace_id);
@@ -1079,6 +1083,13 @@ ParallelWorkerMain(Datum main_arg)
 	 */
 	InvalidateSystemCaches();
 
+	/*
+	 * Restore current role id.  Skip verifying whether session user is
+	 * allowed to become this role and blindly restore the leader's state for
+	 * current role.
+	 */
+	SetCurrentRoleId(fps->outer_user_id, fps->is_superuser);
+
 	/* Restore user ID and security context. */
 	SetUserIdAndSecContext(fps->current_user_id, fps->sec_context);
 
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 969e80f..51748a2 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -446,6 +446,7 @@ char	   *event_source;
 bool		row_security;
 bool		check_function_bodies = true;
 bool		default_with_oids = false;
+bool		session_auth_is_superuser;
 
 int			log_min_error_statement = ERROR;
 int			log_min_messages = WARNING;
@@ -492,7 +493,6 @@ int			huge_pages;
  * and is kept in sync by assign_hooks.
  */
 static char *syslog_ident_str;
-static bool session_auth_is_superuser;
 static double phony_random_seed;
 static char *client_encoding_string;
 static char *datestyle_string;
@@ -8986,12 +8986,18 @@ read_nondefault_variables(void)
  * constants; a few, like server_encoding and lc_ctype, are handled specially
  * outside the serialize/restore procedure.  Therefore, SerializeGUCState()
  * never sends these, and RestoreGUCState() never changes them.
+ *
+ * Role is a special variable in the sense that its current value can be an
+ * invalid value and there are multiple ways by which that can happen (like
+ * after setting the role, someone drops it).  So we handle it outside of
+ * serialize/restore machinery.
  */
 static bool
 can_skip_gucvar(struct config_generic *gconf)
 {
 	return gconf->context == PGC_POSTMASTER ||
-		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT;
+		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT ||
+		strcmp(gconf->name, "role") == 0;
 }
 
 /*
@@ -9252,7 +9258,6 @@ SerializeGUCState(Size maxsize, char *start_address)
 	Size		actual_size;
 	Size		bytes_left;
 	int			i;
-	int			i_role = -1;
 
 	/* Reserve space for saving the actual size of the guc state */
 	Assert(maxsize > sizeof(actual_size));
@@ -9260,19 +9265,7 @@ SerializeGUCState(Size maxsize, char *start_address)
 	bytes_left = maxsize - sizeof(actual_size);
 
 	for (i = 0; i < num_guc_variables; i++)
-	{
-		/*
-		 * It's pretty ugly, but we've got to force "role" to be initialized
-		 * after "session_authorization"; otherwise, the latter will override
-		 * the former.
-		 */
-		if (strcmp(guc_variables[i]->name, "role") == 0)
-			i_role = i;
-		else
-			serialize_variable(&curptr, &bytes_left, guc_variables[i]);
-	}
-	if (i_role >= 0)
-		serialize_variable(&curptr, &bytes_left, guc_variables[i_role]);
+		serialize_variable(&curptr, &bytes_left, guc_variables[i]);
 
 	/* Store actual size without assuming alignment of start_address. */
 	actual_size = maxsize - bytes_left - sizeof(actual_size);
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index c1870d2..aa2c7c1 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -244,6 +244,7 @@ extern bool log_btree_build_stats;
 
 extern PGDLLIMPORT bool check_function_bodies;
 extern bool default_with_oids;
+extern bool	session_auth_is_superuser;
 
 extern int	log_min_error_statement;
 extern int	log_min_messages;
diff --git a/src/test/regress/expected/select_parallel.out b/src/test/regress/expected/select_parallel.out
index 2ae600f..b5287ab 100644
--- a/src/test/regress/expected/select_parallel.out
+++ b/src/test/regress/expected/select_parallel.out
@@ -488,6 +488,22 @@ SELECT make_record(x) FROM (SELECT generate_series(1, 5) x) ss ORDER BY x;
 
 ROLLBACK TO SAVEPOINT settings;
 DROP function make_record(n int);
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+NOTICE:  role "regress_parallel_worker" does not exist, skipping
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+ count 
+-------
+ 10000
+(1 row)
+
+reset force_parallel_mode;
+reset role;
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL force_parallel_mode = 1;
diff --git a/src/test/regress/sql/select_parallel.sql b/src/test/regress/sql/select_parallel.sql
index 89fe80a..801df0b 100644
--- a/src/test/regress/sql/select_parallel.sql
+++ b/src/test/regress/sql/select_parallel.sql
@@ -195,6 +195,17 @@ SELECT make_record(x) FROM (SELECT generate_series(1, 5) x) ss ORDER BY x;
 ROLLBACK TO SAVEPOINT settings;
 DROP function make_record(n int);
 
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+reset force_parallel_mode;
+reset role;
+
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL force_parallel_mode = 1;

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index d683050..6813577 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -75,9 +75,11 @@ typedef struct FixedParallelState
 	Oid			database_id;
 	Oid			authenticated_user_id;
 	Oid			current_user_id;
+	Oid			outer_user_id;
 	Oid			temp_namespace_id;
 	Oid			temp_toast_namespace_id;
 	int			sec_context;
+	bool		is_superuser;
 	PGPROC	   *parallel_master_pgproc;
 	pid_t		parallel_master_pid;
 	BackendId	parallel_master_backend_id;
@@ -201,6 +203,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	Size		segsize = 0;
 	int			i;
 	FixedParallelState *fps;
+	const char *is_superuser_var;
 	dsm_handle	session_dsm_handle = DSM_HANDLE_INVALID;
 	Snapshot	transaction_snapshot = GetTransactionSnapshot();
 	Snapshot	active_snapshot = GetActiveSnapshot();
@@ -296,7 +299,13 @@ InitializeParallelDSM(ParallelContext *pcxt)
 		shm_toc_allocate(pcxt->toc, sizeof(FixedParallelState));
 	fps->database_id = MyDatabaseId;
 	fps->authenticated_user_id = GetAuthenticatedUserId();
+	fps->outer_user_id = GetCurrentRoleId();
 	GetUserIdAndSecContext(&fps->current_user_id, &fps->sec_context);
+	is_superuser_var = GetConfigOptionByName("is_superuser", NULL, true);
+	if (is_superuser_var && strcmp(is_superuser_var, "on") == 0)
+		fps->is_superuser = true;
+	else
+		fps->is_superuser = false;
 	GetTempNamespaceState(&fps->temp_namespace_id,
 						  &fps->temp_toast_namespace_id);
 	fps->parallel_master_pgproc = MyProc;
@@ -1115,6 +1124,13 @@ ParallelWorkerMain(Datum main_arg)
 	 */
 	InvalidateSystemCaches();
 
+	/*
+	 * Restore current role id.  Skip verifying whether session user is
+	 * allowed to become this role and blindly restore the leader's state for
+	 * current role.
+	 */
+	SetCurrentRoleId(fps->outer_user_id, fps->is_superuser);
+
 	/* Restore user ID and security context. */
 	SetUserIdAndSecContext(fps->current_user_id, fps->sec_context);
 
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index ae22185..521c0fc 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -8986,12 +8986,18 @@ read_nondefault_variables(void)
  * constants; a few, like server_encoding and lc_ctype, are handled specially
  * outside the serialize/restore procedure.  Therefore, SerializeGUCState()
  * never sends these, and RestoreGUCState() never changes them.
+ *
+ * Role is a special variable in the sense that its current value can be an
+ * invalid value and there are multiple ways by which that can happen (like
+ * after setting the role, someone drops it).  So we handle it outside of
+ * serialize/restore machinery.
  */
 static bool
 can_skip_gucvar(struct config_generic *gconf)
 {
 	return gconf->context == PGC_POSTMASTER ||
-		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT;
+		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT ||
+		strcmp(gconf->name, "role") == 0;
 }
 
 /*
@@ -9252,7 +9258,6 @@ SerializeGUCState(Size maxsize, char *start_address)
 	Size		actual_size;
 	Size		bytes_left;
 	int			i;
-	int			i_role = -1;
 
 	/* Reserve space for saving the actual size of the guc state */
 	Assert(maxsize > sizeof(actual_size));
@@ -9260,19 +9265,7 @@ SerializeGUCState(Size maxsize, char *start_address)
 	bytes_left = maxsize - sizeof(actual_size);
 
 	for (i = 0; i < num_guc_variables; i++)
-	{
-		/*
-		 * It's pretty ugly, but we've got to force "role" to be initialized
-		 * after "session_authorization"; otherwise, the latter will override
-		 * the former.
-		 */
-		if (strcmp(guc_variables[i]->name, "role") == 0)
-			i_role = i;
-		else
-			serialize_variable(&curptr, &bytes_left, guc_variables[i]);
-	}
-	if (i_role >= 0)
-		serialize_variable(&curptr, &bytes_left, guc_variables[i_role]);
+		serialize_variable(&curptr, &bytes_left, guc_variables[i]);
 
 	/* Store actual size without assuming alignment of start_address. */
 	actual_size = maxsize - bytes_left - sizeof(actual_size);
diff --git a/src/test/regress/expected/select_parallel.out b/src/test/regress/expected/select_parallel.out
index 3c63ad1..ac9ad06 100644
--- a/src/test/regress/expected/select_parallel.out
+++ b/src/test/regress/expected/select_parallel.out
@@ -508,6 +508,22 @@ SELECT make_record(x) FROM (SELECT generate_series(1, 5) x) ss ORDER BY x;
 
 ROLLBACK TO SAVEPOINT settings;
 DROP function make_record(n int);
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+NOTICE:  role "regress_parallel_worker" does not exist, skipping
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+ count 
+-------
+ 10000
+(1 row)
+
+reset force_parallel_mode;
+reset role;
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL force_parallel_mode = 1;
diff --git a/src/test/regress/sql/select_parallel.sql b/src/test/regress/sql/select_parallel.sql
index 720495c..495f033 100644
--- a/src/test/regress/sql/select_parallel.sql
+++ b/src/test/regress/sql/select_parallel.sql
@@ -201,6 +201,17 @@ SELECT make_record(x) FROM (SELECT generate_series(1, 5) x) ss ORDER BY x;
 ROLLBACK TO SAVEPOINT settings;
 DROP function make_record(n int);
 
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+reset force_parallel_mode;
+reset role;
+
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL force_parallel_mode = 1;

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index d683050..1f542ed 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -75,9 +75,11 @@ typedef struct FixedParallelState
 	Oid			database_id;
 	Oid			authenticated_user_id;
 	Oid			current_user_id;
+	Oid			outer_user_id;
 	Oid			temp_namespace_id;
 	Oid			temp_toast_namespace_id;
 	int			sec_context;
+	bool		is_superuser;
 	PGPROC	   *parallel_master_pgproc;
 	pid_t		parallel_master_pid;
 	BackendId	parallel_master_backend_id;
@@ -296,6 +298,8 @@ InitializeParallelDSM(ParallelContext *pcxt)
 		shm_toc_allocate(pcxt->toc, sizeof(FixedParallelState));
 	fps->database_id = MyDatabaseId;
 	fps->authenticated_user_id = GetAuthenticatedUserId();
+	fps->outer_user_id = GetCurrentRoleId();
+	fps->is_superuser = session_auth_is_superuser;
 	GetUserIdAndSecContext(&fps->current_user_id, &fps->sec_context);
 	GetTempNamespaceState(&fps->temp_namespace_id,
 						  &fps->temp_toast_namespace_id);
@@ -1115,6 +1119,13 @@ ParallelWorkerMain(Datum main_arg)
 	 */
 	InvalidateSystemCaches();
 
+	/*
+	 * Restore current role id.  Skip verifying whether session user is
+	 * allowed to become this role and blindly restore the leader's state for
+	 * current role.
+	 */
+	SetCurrentRoleId(fps->outer_user_id, fps->is_superuser);
+
 	/* Restore user ID and security context. */
 	SetUserIdAndSecContext(fps->current_user_id, fps->sec_context);
 
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index ae22185..65372d7 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -446,6 +446,7 @@ char	   *event_source;
 bool		row_security;
 bool		check_function_bodies = true;
 bool		default_with_oids = false;
+bool		session_auth_is_superuser;
 
 int			log_min_error_statement = ERROR;
 int			log_min_messages = WARNING;
@@ -492,7 +493,6 @@ int			huge_pages;
  * and is kept in sync by assign_hooks.
  */
 static char *syslog_ident_str;
-static bool session_auth_is_superuser;
 static double phony_random_seed;
 static char *client_encoding_string;
 static char *datestyle_string;
@@ -8986,12 +8986,18 @@ read_nondefault_variables(void)
  * constants; a few, like server_encoding and lc_ctype, are handled specially
  * outside the serialize/restore procedure.  Therefore, SerializeGUCState()
  * never sends these, and RestoreGUCState() never changes them.
+ *
+ * Role is a special variable in the sense that its current value can be an
+ * invalid value and there are multiple ways by which that can happen (like
+ * after setting the role, someone drops it).  So we handle it outside of
+ * serialize/restore machinery.
  */
 static bool
 can_skip_gucvar(struct config_generic *gconf)
 {
 	return gconf->context == PGC_POSTMASTER ||
-		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT;
+		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT ||
+		strcmp(gconf->name, "role") == 0;
 }
 
 /*
@@ -9252,7 +9258,6 @@ SerializeGUCState(Size maxsize, char *start_address)
 	Size		actual_size;
 	Size		bytes_left;
 	int			i;
-	int			i_role = -1;
 
 	/* Reserve space for saving the actual size of the guc state */
 	Assert(maxsize > sizeof(actual_size));
@@ -9260,19 +9265,7 @@ SerializeGUCState(Size maxsize, char *start_address)
 	bytes_left = maxsize - sizeof(actual_size);
 
 	for (i = 0; i < num_guc_variables; i++)
-	{
-		/*
-		 * It's pretty ugly, but we've got to force "role" to be initialized
-		 * after "session_authorization"; otherwise, the latter will override
-		 * the former.
-		 */
-		if (strcmp(guc_variables[i]->name, "role") == 0)
-			i_role = i;
-		else
-			serialize_variable(&curptr, &bytes_left, guc_variables[i]);
-	}
-	if (i_role >= 0)
-		serialize_variable(&curptr, &bytes_left, guc_variables[i_role]);
+		serialize_variable(&curptr, &bytes_left, guc_variables[i]);
 
 	/* Store actual size without assuming alignment of start_address. */
 	actual_size = maxsize - bytes_left - sizeof(actual_size);
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index 467125a..aa130cd 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -245,6 +245,7 @@ extern bool log_btree_build_stats;
 
 extern PGDLLIMPORT bool check_function_bodies;
 extern bool default_with_oids;
+extern bool	session_auth_is_superuser;
 
 extern int	log_min_error_statement;
 extern int	log_min_messages;
diff --git a/src/test/regress/expected/select_parallel.out b/src/test/regress/expected/select_parallel.out
index 3c63ad1..ac9ad06 100644
--- a/src/test/regress/expected/select_parallel.out
+++ b/src/test/regress/expected/select_parallel.out
@@ -508,6 +508,22 @@ SELECT make_record(x) FROM (SELECT generate_series(1, 5) x) ss ORDER BY x;
 
 ROLLBACK TO SAVEPOINT settings;
 DROP function make_record(n int);
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+NOTICE:  role "regress_parallel_worker" does not exist, skipping
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+ count 
+-------
+ 10000
+(1 row)
+
+reset force_parallel_mode;
+reset role;
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL force_parallel_mode = 1;
diff --git a/src/test/regress/sql/select_parallel.sql b/src/test/regress/sql/select_parallel.sql
index 720495c..495f033 100644
--- a/src/test/regress/sql/select_parallel.sql
+++ b/src/test/regress/sql/select_parallel.sql
@@ -201,6 +201,17 @@ SELECT make_record(x) FROM (SELECT generate_series(1, 5) x) ss ORDER BY x;
 ROLLBACK TO SAVEPOINT settings;
 DROP function make_record(n int);
 
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+reset force_parallel_mode;
+reset role;
+
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL force_parallel_mode = 1;

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index ce1b907..62b287e 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -71,9 +71,11 @@ typedef struct FixedParallelState
 	Oid			database_id;
 	Oid			authenticated_user_id;
 	Oid			current_user_id;
+	Oid			outer_user_id;
 	Oid			temp_namespace_id;
 	Oid			temp_toast_namespace_id;
 	int			sec_context;
+	bool		is_superuser;
 	PGPROC	   *parallel_master_pgproc;
 	pid_t		parallel_master_pid;
 	BackendId	parallel_master_backend_id;
@@ -197,6 +199,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	Size		segsize = 0;
 	int			i;
 	FixedParallelState *fps;
+	const char *is_superuser_var;
 	Snapshot	transaction_snapshot = GetTransactionSnapshot();
 	Snapshot	active_snapshot = GetActiveSnapshot();
 
@@ -275,7 +278,13 @@ InitializeParallelDSM(ParallelContext *pcxt)
 		shm_toc_allocate(pcxt->toc, sizeof(FixedParallelState));
 	fps->database_id = MyDatabaseId;
 	fps->authenticated_user_id = GetAuthenticatedUserId();
+	fps->outer_user_id = GetCurrentRoleId();
 	GetUserIdAndSecContext(&fps->current_user_id, &fps->sec_context);
+	is_superuser_var = GetConfigOptionByName("is_superuser", NULL, true);
+	if (is_superuser_var && strcmp(is_superuser_var, "on") == 0)
+		fps->is_superuser = true;
+	else
+		fps->is_superuser = false;
 	GetTempNamespaceState(&fps->temp_namespace_id,
 						  &fps->temp_toast_namespace_id);
 	fps->parallel_master_pgproc = MyProc;
@@ -1079,6 +1088,13 @@ ParallelWorkerMain(Datum main_arg)
 	 */
 	InvalidateSystemCaches();
 
+	/*
+	 * Restore current role id.  Skip verifying whether session user is
+	 * allowed to become this role and blindly restore the leader's state for
+	 * current role.
+	 */
+	SetCurrentRoleId(fps->outer_user_id, fps->is_superuser);
+
 	/* Restore user ID and security context. */
 	SetUserIdAndSecContext(fps->current_user_id, fps->sec_context);
 
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 58a4cf9..490acf7 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -8986,12 +8986,18 @@ read_nondefault_variables(void)
  * constants; a few, like server_encoding and lc_ctype, are handled specially
  * outside the serialize/restore procedure.  Therefore, SerializeGUCState()
  * never sends these, and RestoreGUCState() never changes them.
+ *
+ * Role is a special variable in the sense that its current value can be an
+ * invalid value and there are multiple ways by which that can happen (like
+ * after setting the role, someone drops it).  So we handle it outside of
+ * serialize/restore machinery.
  */
 static bool
 can_skip_gucvar(struct config_generic *gconf)
 {
 	return gconf->context == PGC_POSTMASTER ||
-		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT;
+		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT ||
+		strcmp(gconf->name, "role") == 0;
 }
 
 /*
@@ -9252,7 +9258,6 @@ SerializeGUCState(Size maxsize, char *start_address)
 	Size		actual_size;
 	Size		bytes_left;
 	int			i;
-	int			i_role = -1;
 
 	/* Reserve space for saving the actual size of the guc state */
 	Assert(maxsize > sizeof(actual_size));
@@ -9260,19 +9265,7 @@ SerializeGUCState(Size maxsize, char *start_address)
 	bytes_left = maxsize - sizeof(actual_size);
 
 	for (i = 0; i < num_guc_variables; i++)
-	{
-		/*
-		 * It's pretty ugly, but we've got to force "role" to be initialized
-		 * after "session_authorization"; otherwise, the latter will override
-		 * the former.
-		 */
-		if (strcmp(guc_variables[i]->name, "role") == 0)
-			i_role = i;
-		else
-			serialize_variable(&curptr, &bytes_left, guc_variables[i]);
-	}
-	if (i_role >= 0)
-		serialize_variable(&curptr, &bytes_left, guc_variables[i_role]);
+		serialize_variable(&curptr, &bytes_left, guc_variables[i]);
 
 	/* Store actual size without assuming alignment of start_address. */
 	actual_size = maxsize - bytes_left - sizeof(actual_size);
diff --git a/src/test/regress/expected/select_parallel.out b/src/test/regress/expected/select_parallel.out
index 7458870..6bbcd34 100644
--- a/src/test/regress/expected/select_parallel.out
+++ b/src/test/regress/expected/select_parallel.out
@@ -424,6 +424,22 @@ select string4 from tenk1 order by string4 limit 5;
 
 reset max_parallel_workers;
 reset enable_hashagg;
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+NOTICE:  role "regress_parallel_worker" does not exist, skipping
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+ count 
+-------
+ 10000
+(1 row)
+
+reset force_parallel_mode;
+reset role;
 set force_parallel_mode=1;
 explain (costs off)
   select stringu1::int2 from tenk1 where unique1 = 1;
diff --git a/src/test/regress/sql/select_parallel.sql b/src/test/regress/sql/select_parallel.sql
index 09c1b03..cf02d84 100644
--- a/src/test/regress/sql/select_parallel.sql
+++ b/src/test/regress/sql/select_parallel.sql
@@ -162,6 +162,17 @@ select string4 from tenk1 order by string4 limit 5;
 reset max_parallel_workers;
 reset enable_hashagg;
 
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+reset force_parallel_mode;
+reset role;
+
 set force_parallel_mode=1;
 
 explain (costs off)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index ce1b907..e1a6a75 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -71,9 +71,11 @@ typedef struct FixedParallelState
 	Oid			database_id;
 	Oid			authenticated_user_id;
 	Oid			current_user_id;
+	Oid			outer_user_id;
 	Oid			temp_namespace_id;
 	Oid			temp_toast_namespace_id;
 	int			sec_context;
+	bool		is_superuser;
 	PGPROC	   *parallel_master_pgproc;
 	pid_t		parallel_master_pid;
 	BackendId	parallel_master_backend_id;
@@ -275,6 +277,8 @@ InitializeParallelDSM(ParallelContext *pcxt)
 		shm_toc_allocate(pcxt->toc, sizeof(FixedParallelState));
 	fps->database_id = MyDatabaseId;
 	fps->authenticated_user_id = GetAuthenticatedUserId();
+	fps->outer_user_id = GetCurrentRoleId();
+	fps->is_superuser = session_auth_is_superuser;
 	GetUserIdAndSecContext(&fps->current_user_id, &fps->sec_context);
 	GetTempNamespaceState(&fps->temp_namespace_id,
 						  &fps->temp_toast_namespace_id);
@@ -1079,6 +1083,13 @@ ParallelWorkerMain(Datum main_arg)
 	 */
 	InvalidateSystemCaches();
 
+	/*
+	 * Restore current role id.  Skip verifying whether session user is
+	 * allowed to become this role and blindly restore the leader's state for
+	 * current role.
+	 */
+	SetCurrentRoleId(fps->outer_user_id, fps->is_superuser);
+
 	/* Restore user ID and security context. */
 	SetUserIdAndSecContext(fps->current_user_id, fps->sec_context);
 
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 58a4cf9..bee9cc5 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -446,6 +446,7 @@ char	   *event_source;
 bool		row_security;
 bool		check_function_bodies = true;
 bool		default_with_oids = false;
+bool		session_auth_is_superuser;
 
 int			log_min_error_statement = ERROR;
 int			log_min_messages = WARNING;
@@ -492,7 +493,6 @@ int			huge_pages;
  * and is kept in sync by assign_hooks.
  */
 static char *syslog_ident_str;
-static bool session_auth_is_superuser;
 static double phony_random_seed;
 static char *client_encoding_string;
 static char *datestyle_string;
@@ -8986,12 +8986,18 @@ read_nondefault_variables(void)
  * constants; a few, like server_encoding and lc_ctype, are handled specially
  * outside the serialize/restore procedure.  Therefore, SerializeGUCState()
  * never sends these, and RestoreGUCState() never changes them.
+ *
+ * Role is a special variable in the sense that its current value can be an
+ * invalid value and there are multiple ways by which that can happen (like
+ * after setting the role, someone drops it).  So we handle it outside of
+ * serialize/restore machinery.
  */
 static bool
 can_skip_gucvar(struct config_generic *gconf)
 {
 	return gconf->context == PGC_POSTMASTER ||
-		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT;
+		gconf->context == PGC_INTERNAL || gconf->source == PGC_S_DEFAULT ||
+		strcmp(gconf->name, "role") == 0;
 }
 
 /*
@@ -9252,7 +9258,6 @@ SerializeGUCState(Size maxsize, char *start_address)
 	Size		actual_size;
 	Size		bytes_left;
 	int			i;
-	int			i_role = -1;
 
 	/* Reserve space for saving the actual size of the guc state */
 	Assert(maxsize > sizeof(actual_size));
@@ -9260,19 +9265,7 @@ SerializeGUCState(Size maxsize, char *start_address)
 	bytes_left = maxsize - sizeof(actual_size);
 
 	for (i = 0; i < num_guc_variables; i++)
-	{
-		/*
-		 * It's pretty ugly, but we've got to force "role" to be initialized
-		 * after "session_authorization"; otherwise, the latter will override
-		 * the former.
-		 */
-		if (strcmp(guc_variables[i]->name, "role") == 0)
-			i_role = i;
-		else
-			serialize_variable(&curptr, &bytes_left, guc_variables[i]);
-	}
-	if (i_role >= 0)
-		serialize_variable(&curptr, &bytes_left, guc_variables[i_role]);
+		serialize_variable(&curptr, &bytes_left, guc_variables[i]);
 
 	/* Store actual size without assuming alignment of start_address. */
 	actual_size = maxsize - bytes_left - sizeof(actual_size);
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index c1870d2..aa2c7c1 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -244,6 +244,7 @@ extern bool log_btree_build_stats;
 
 extern PGDLLIMPORT bool check_function_bodies;
 extern bool default_with_oids;
+extern bool	session_auth_is_superuser;
 
 extern int	log_min_error_statement;
 extern int	log_min_messages;
diff --git a/src/test/regress/expected/select_parallel.out b/src/test/regress/expected/select_parallel.out
index 7458870..6bbcd34 100644
--- a/src/test/regress/expected/select_parallel.out
+++ b/src/test/regress/expected/select_parallel.out
@@ -424,6 +424,22 @@ select string4 from tenk1 order by string4 limit 5;
 
 reset max_parallel_workers;
 reset enable_hashagg;
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+NOTICE:  role "regress_parallel_worker" does not exist, skipping
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+ count 
+-------
+ 10000
+(1 row)
+
+reset force_parallel_mode;
+reset role;
 set force_parallel_mode=1;
 explain (costs off)
   select stringu1::int2 from tenk1 where unique1 = 1;
diff --git a/src/test/regress/sql/select_parallel.sql b/src/test/regress/sql/select_parallel.sql
index 09c1b03..cf02d84 100644
--- a/src/test/regress/sql/select_parallel.sql
+++ b/src/test/regress/sql/select_parallel.sql
@@ -162,6 +162,17 @@ select string4 from tenk1 order by string4 limit 5;
 reset max_parallel_workers;
 reset enable_hashagg;
 
+-- test the sanity of parallel query after the active role is dropped.
+drop role if exists regress_parallel_worker;
+create role regress_parallel_worker;
+set role regress_parallel_worker;
+reset session authorization;
+drop role regress_parallel_worker;
+set force_parallel_mode = 1;
+select count(*) from tenk1;
+reset force_parallel_mode;
+reset role;
+
 set force_parallel_mode=1;
 
 explain (costs off)