diff --git a/src/dbtest/src/mda_detect.py b/src/dbtest/src/mda_detect.py
index 982361ea..8774473d 100644
--- a/src/dbtest/src/mda_detect.py
+++ b/src/dbtest/src/mda_detect.py
@@ -33,6 +33,8 @@ class Txn:
     def __init__(self):
         self.begin_ts = -1
         self.end_ts = 99999999999999999999
+        self.isolation_level = "SERIALIZABLE"  # Default to SERIALIZABLE isolation level
+
 
 """
 Find the total variable number.
@@ -150,6 +152,24 @@ def set_finish_time(op_time, data_op_list, query, txn, version_list):
 # or the start time of the second transaction is less than the end time of the first transaction
 # we think they are concurrent
 def check_concurrency(data1, data2, txn):
+    # Get isolation levels of both transactions
+    level1 = txn[data1.txn_num].isolation_level
+    level2 = txn[data2.txn_num].isolation_level
+    
+    # Relax checks for READ UNCOMMITTED level
+    if level1 == "READ UNCOMMITTED" or level2 == "READ UNCOMMITTED":
+        return True
+    
+    # Partial relaxation for READ COMMITTED level
+    if level1 == "READ COMMITTED" or level2 == "READ COMMITTED":
+        if txn[data2.txn_num].begin_ts < txn[data1.txn_num].end_ts:
+            return True
+        elif txn[data1.txn_num].begin_ts < txn[data2.txn_num].end_ts:
+            return True
+        else:
+            return False
+    
+    # Strict checks for REPEATABLE READ and SERIALIZABLE levels
     if txn[data2.txn_num].begin_ts < txn[data1.txn_num].end_ts:
         return True
     elif txn[data1.txn_num].begin_ts < txn[data2.txn_num].end_ts:
@@ -175,6 +195,10 @@ def check_concurrency(data1, data2, txn):
 # decide which operation comes first depending on the read or write version
 # if later operation happened after the first txn commit time, edge type will add "C"
 def get_edge_type(data1, data2, txn):
+    # Get transaction isolation levels
+    level1 = txn[data1.txn_num].isolation_level
+    level2 = txn[data2.txn_num].isolation_level
+    
     if data1.value <= data2.value:
         before, after = data1, data2
     else:
@@ -184,10 +208,15 @@ def get_edge_type(data1, data2, txn):
     #         before, after = data2, data1
     #     else:
     #         before, after = data1, data2
-    if data2.op_time > txn[data1.txn_num].end_ts:
+    
+    # Adjust edge type based on isolation level
+    if level1 == "READ UNCOMMITTED" or level2 == "READ UNCOMMITTED":
+        state = ""
+    elif data2.op_time > txn[data1.txn_num].end_ts:
         state = "C"
     else:
         state = ""
+    
     return before.op_type + state + after.op_type, before, after
 
 
@@ -236,7 +265,13 @@ def build_graph(data_op_list, indegree, edge, txn):
 def insert_edge(data1, data2, indegree, edge, txn):
     if check_concurrency(data1, data2, txn):
         edge_type, data1, data2 = get_edge_type(data1, data2, txn)
-        if edge_type != "RR" and edge_type != "RCR" and data1.txn_num != data2.txn_num:
+        # Adjust edge insertion based on isolation level
+        level1 = txn[data1.txn_num].isolation_level
+        level2 = txn[data2.txn_num].isolation_level
+        
+        if (edge_type != "RR" and edge_type != "RCR" and 
+            data1.txn_num != data2.txn_num and
+            not (level1 == "READ UNCOMMITTED" and level2 == "READ UNCOMMITTED")):
             indegree[data2.txn_num] += 1
             edge[data1.txn_num].append(Edge(edge_type, data2.txn_num))
 
@@ -500,6 +535,18 @@ def operation_record(total_num, query, txn, data_op_list, version_list):
     if op_time == 0 and query.find("INSERT") != -1:
         init_record(query, version_list)
         return error_message
+    # Set transaction isolation level
+    if query.find("SET TRANSACTION ISOLATION LEVEL") != -1:
+        if query.find("READ UNCOMMITTED") != -1:
+            txn[txn_num].isolation_level = "READ UNCOMMITTED"
+        elif query.find("READ COMMITTED") != -1:
+            txn[txn_num].isolation_level = "READ COMMITTED"
+        elif query.find("REPEATABLE READ") != -1:
+            txn[txn_num].isolation_level = "REPEATABLE READ"
+        elif query.find("SERIALIZABLE") != -1:
+            txn[txn_num].isolation_level = "SERIALIZABLE"
+        return error_message
+
     if query.find("returnresult") != -1:
         error_message = readVersion_record(query, op_time, data_op_list, version_list)
         return error_message