diff --git a/src/backend/commands/resgroupcmds.c b/src/backend/commands/resgroupcmds.c
index 384675edb7f..e5ba72a3054 100644
--- a/src/backend/commands/resgroupcmds.c
+++ b/src/backend/commands/resgroupcmds.c
@@ -715,47 +715,25 @@ GetResGroupIdForRole(Oid roleid)
 {
 	HeapTuple	tuple;
 	Oid			groupId;
-	bool		isNull;
-	Relation	rel;
-	ScanKeyData	key;
-	SysScanDesc	 sscan;
-
-	rel = table_open(AuthIdRelationId, AccessShareLock);
-
-	ScanKeyInit(&key,
-				Anum_pg_authid_oid,
-				BTEqualStrategyNumber, F_OIDEQ,
-				ObjectIdGetDatum(roleid));
-
-	sscan = systable_beginscan(rel, AuthIdOidIndexId, true, NULL, 1, &key);
+	bool		isNull = true;
 
-	tuple = systable_getnext(sscan);
+	/*
+	 * Prefer syscache lookup to avoid taking explicit catalog scan/snapshot
+	 * which may install xmin in the current process.  Use the AUTHOID
+	 * syscache to fetch pg_authid tuple for the given role Oid.
+	 */
+	tuple = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid));
 	if (!HeapTupleIsValid(tuple))
 	{
-		systable_endscan(sscan);
-		table_close(rel, AccessShareLock);
-
-		/*
-		 * Role should have been dropped by other backends in this case, so this
-		 * session cannot execute any command anymore
-		 */
 		ereport(ERROR,
 				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				errmsg("role with Oid %u was dropped", roleid),
-				errdetail("Cannot execute commands anymore, please terminate this session.")));
+				 errmsg("role with Oid %u was dropped", roleid),
+				 errdetail("Cannot execute commands anymore, please terminate this session.")));
 	}
 
-	/* must access tuple before systable_endscan */
-	groupId = DatumGetObjectId(heap_getattr(tuple, Anum_pg_authid_rolresgroup,
-							   rel->rd_att, &isNull));
+	groupId = DatumGetObjectId(SysCacheGetAttr(AUTHOID, tuple, Anum_pg_authid_rolresgroup, &isNull));
 
-	systable_endscan(sscan);
-
-	/*
-	 * release lock here to guarantee we have no lock held when acquiring
-	 * resource group slot
-	 */
-	table_close(rel, AccessShareLock);
+	ReleaseSysCache(tuple);
 
 	if (!OidIsValid(groupId))
 		groupId = InvalidOid;