diff --git a/src/entry/Maat_hierarchy.cpp b/src/entry/Maat_hierarchy.cpp
index dc1974a..ca6da37 100644
--- a/src/entry/Maat_hierarchy.cpp
+++ b/src/entry/Maat_hierarchy.cpp
@@ -1119,15 +1119,16 @@ struct region2clause_value* Maat_hierarchy_build_region2clause_hash(struct Maat_
 			{
 				g2r=ALLOC(struct group2region, 1);
 				utarray_new(g2r->region_ids, &ut_region_id_icd);
+				utarray_reserve(g2r->region_ids, group->ref_by_region_cnt);
 				g2r->group_id=group->top_group_ids[i];
 				HASH_ADD_INT(g2r_hash, group_id, g2r);
 			}
-			if(utarray_find(g2r->region_ids, &(region->region_id), compare_region_id))
-			{
-				assert(0);
-			}
+			
+			//One region belongs to one group, one group may have many regions. So duplicate region check is unnecessary.
+			//if(utarray_find(g2r->region_ids, &(region->region_id), compare_region_id)) assert(0);
+
 			utarray_push_back(g2r->region_ids, &(region->region_id));
-			utarray_sort(g2r->region_ids, compare_region_id);
+			//utarray_sort(g2r->region_ids, compare_region_id);
 		}
 	}
 
@@ -1178,10 +1179,18 @@ struct region2clause_value* Maat_hierarchy_build_region2clause_hash(struct Maat_
 		}
 
 	}
-	
+	int tmp1=0, tmp2=0;
 	HASH_ITER(hh, g2r_hash, g2r, g2r_tmp)
 	{
 		HASH_DEL(g2r_hash, g2r);
+		//Sanity Check
+		utarray_sort(g2r->region_ids, compare_region_id);
+		for(i=1; i<utarray_len(g2r->region_ids); i++)
+		{			
+			tmp1=*((int*)utarray_eltptr(g2r->region_ids, i-1));
+			tmp2=*((int*)utarray_eltptr(g2r->region_ids, i));
+			assert(tmp1!=tmp2);
+		}
 		utarray_free(g2r->region_ids);
 		g2r->region_ids=NULL;
 		free(g2r);
diff --git a/test/perf_test_maatframe.cpp b/test/perf_test_maatframe.cpp
index d51a4c0..fa1f2bf 100644
--- a/test/perf_test_maatframe.cpp
+++ b/test/perf_test_maatframe.cpp
@@ -372,8 +372,10 @@ const char* high_match_string="maatframe!";
 struct high_match_rate_thread_para
 {
 	int thread_id;
+	int test_count;
 	Maat_feather_t feather;
 	const char* expr_table_name;
+	unsigned long long time_elapse_ms;
 };
 void* high_match_rate_scan_thread(void *arg)
 {
@@ -385,10 +387,13 @@ void* high_match_rate_scan_thread(void *arg)
 	struct Maat_rule_t result;
 	scan_status_t mid=NULL;
 
-	int table_id=0, i=0, ret=0, test_times=10*1000*1000, hit_times=0;
+	int table_id=0, i=0, ret=0, hit_times=0;
 	table_id=Maat_table_register(feather, expr_table_name);
 	memset(&result, 0, sizeof(result));
-	for(i=0; i<test_times; i++)
+	struct timespec start, end;
+	
+	clock_gettime(CLOCK_MONOTONIC, &start);
+	for(i=0; i<para->test_count; i++)
 	{
 		ret=Maat_full_scan_string(feather, table_id, CHARSET_GBK, high_match_string, strlen(high_match_string), 
 							&result, NULL, 1,
@@ -399,9 +404,10 @@ void* high_match_rate_scan_thread(void *arg)
 		}
 		Maat_clean_status(&mid);
 	}
-
+	clock_gettime(CLOCK_MONOTONIC, &end);
+	para->time_elapse_ms=(end.tv_sec-start.tv_sec)*1000+(end.tv_nsec-start.tv_nsec)/1000000;
 	int* is_all_hit=(int*)malloc(sizeof(int));
-	*is_all_hit=(hit_times==test_times)?1:0;
+	*is_all_hit=(hit_times==para->test_count)?1:0;
 	return is_all_hit;
 }
 void* high_match_rate_update_thread(void *arg)
@@ -453,6 +459,7 @@ TEST_F(MaatCMDPerfTest, HighMatchRateOnMultiThread)
 	Maat_command_batch_commit(batch);
 	sleep(4);
 	int global_thread_num=4;
+	unsigned long long time_elapse_ms=0, scan_count=0, scan_per_second=0;
 	pthread_t threads[global_thread_num+1];	
 	struct high_match_rate_thread_para thread_para[global_thread_num+1];
 	for(i=0; i<global_thread_num+1; i++)
@@ -460,24 +467,31 @@ TEST_F(MaatCMDPerfTest, HighMatchRateOnMultiThread)
 		thread_para[i].feather=feather;
 		thread_para[i].thread_id=i;
 		thread_para[i].expr_table_name=expr_table_name;
+		thread_para[i].test_count=10*1000*1000;
+		thread_para[i].time_elapse_ms=0;
 		if(i<global_thread_num)
 		{
 			pthread_create(&(threads[i]), NULL, high_match_rate_scan_thread, thread_para+i);
 		}
 		else
 		{
+			thread_para[i].test_count=0;
 			pthread_create(&(threads[i]), NULL, high_match_rate_update_thread, thread_para+i);
 		}
 	}
 
 	for(i=0; i<global_thread_num+1; i++)
 	{
-		pthread_join(threads[i], (void**)&is_all_hit);
+		pthread_join(threads[i], (void**)&is_all_hit);	
+		time_elapse_ms+=thread_para[i].time_elapse_ms;
+		scan_count+=thread_para[i].test_count;
 		EXPECT_EQ(*is_all_hit, 1);
 		*is_all_hit=0;
 		free(is_all_hit);
 	}
-
+	scan_per_second=scan_count*1000/time_elapse_ms;
+	EXPECT_GT(scan_per_second, 800*1000);
+	printf("High Match on Multi-Thread speed %lld lookups/s\n", scan_per_second);
 }
 
 #define IP_PLUGIN_EX_DATA