diff --git a/lib/execution/executors/executor_test/btree_index_executor_test.go b/lib/execution/executors/executor_test/btree_index_executor_test.go
index d42cef5c..51832e87 100644
--- a/lib/execution/executors/executor_test/btree_index_executor_test.go
+++ b/lib/execution/executors/executor_test/btree_index_executor_test.go
@@ -127,9 +127,9 @@ func testBTreeParallelTxnStrideRoot[T int32 | float32 | string](t *testing.T, ke
 
 		//InnerTestParallelTxnsQueryingIndexUsedColumns[T](t, keyType, 800, 30000, 13, 0, bpoolSize, index_constants.INDEX_KIND_BTREE, PARALLEL_EXEC, 20)
 
-		//InnerTestParallelTxnsQueryingIndexUsedColumns[T](t, keyType, 800, 1000, 13, 0, bpoolSize, index_constants.INDEX_KIND_BTREE, SERIAL_EXEC, 1)
+		//InnerTestParallelTxnsQueryingIndexUsedColumns[T](t, keyType, 800, 3000, 13, 0, bpoolSize, index_constants.INDEX_KIND_BTREE, SERIAL_EXEC, 1)
 
-		InnerTestParallelTxnsQueryingIndexUsedColumns[T](t, keyType, 800, 3000, 13, 0, bpoolSize, index_constants.INDEX_KIND_BTREE, PARALLEL_EXEC, 20)
+		InnerTestParallelTxnsQueryingIndexUsedColumns[T](t, keyType, 800, 30000, 13, 0, bpoolSize, index_constants.INDEX_KIND_BTREE, PARALLEL_EXEC, 20)
 	case types.Float:
 		InnerTestParallelTxnsQueryingIndexUsedColumns[T](t, keyType, 240, 1000, 13, 0, bpoolSize, index_constants.INDEX_KIND_BTREE, PARALLEL_EXEC, 20)
 	case types.Varchar:
@@ -138,8 +138,8 @@ func testBTreeParallelTxnStrideRoot[T int32 | float32 | string](t *testing.T, ke
 		//InnerTestParallelTxnsQueryingIndexUsedColumns[T](t, keyType, 400, 1000, 17, 0, bpoolSize, index_constants.INDEX_KIND_BTREE, SERIAL_EXEC, 1)
 		//InnerTestParallelTxnsQueryingIndexUsedColumns[T](t, keyType, 800, 5000, 17, 0, bpoolSize, index_constants.INDEX_KIND_BTREE, SERIAL_EXEC, 1)
 
-		//InnerTestParallelTxnsQueryingIndexUsedColumns[T](t, keyType, 800, 3000, 17, 0, bpoolSize, index_constants.INDEX_KIND_BTREE, SERIAL_EXEC, 1)
-		InnerTestParallelTxnsQueryingIndexUsedColumns[T](t, keyType, 800, 3000, 17, 0, bpoolSize, index_constants.INDEX_KIND_BTREE, PARALLEL_EXEC, 20)
+		InnerTestParallelTxnsQueryingIndexUsedColumns[T](t, keyType, 800, 3000, 17, 0, bpoolSize, index_constants.INDEX_KIND_BTREE, SERIAL_EXEC, 1)
+		//InnerTestParallelTxnsQueryingIndexUsedColumns[T](t, keyType, 800, 3000, 17, 0, bpoolSize, index_constants.INDEX_KIND_BTREE, PARALLEL_EXEC, 20)
 	default:
 		panic("not implemented!")
 	}
diff --git a/lib/samehada/samehada_util/samehada_util.go b/lib/samehada/samehada_util/samehada_util.go
index 3aa43e97..21a05dce 100644
--- a/lib/samehada/samehada_util/samehada_util.go
+++ b/lib/samehada/samehada_util/samehada_util.go
@@ -180,7 +180,7 @@ func GetRandomPrimitiveVal[T int32 | float32 | string](keyType types.TypeID, max
 		// TODO: (SDB) FOR DEBUG: length is fixed
 		//var ret interface{} = *GetRandomStr(50, false)
 		//var ret interface{} = *GetRandomStr(50, true)
-		var ret interface{} = *GetRandomStr(50, false)
+		var ret interface{} = *GetRandomStr(50, true)
 		return ret.(T)
 	default:
 		panic("not supported keyType")
diff --git a/lib/storage/index/btree_index.go b/lib/storage/index/btree_index.go
index c9328352..9f63ad42 100644
--- a/lib/storage/index/btree_index.go
+++ b/lib/storage/index/btree_index.go
@@ -140,7 +140,7 @@ func (btidx *BTreeIndex) ScanKey(key *tuple.Tuple, txn interface{}) []page.RID {
 	smallestKeyVal := samehada_util.EncodeValueAndRIDToDicOrderComparableVarchar(&orgKeyVal, &page.RID{0, 0})
 	biggestKeyVal := samehada_util.EncodeValueAndRIDToDicOrderComparableVarchar(&orgKeyVal, &page.RID{math.MaxInt32, math.MaxUint32})
 
-	//btidx.rwMtx.RLock()
+	btidx.rwMtx.RLock()
 	// Attention: returned itr's containing keys are string type Value which is constructed with byte arr of concatenated  original key and value
 	rangeItr := btidx.container.GetRangeItr(smallestKeyVal.SerializeOnlyVal(), biggestKeyVal.SerializeOnlyVal())
 
@@ -152,7 +152,7 @@ func (btidx *BTreeIndex) ScanKey(key *tuple.Tuple, txn interface{}) []page.RID {
 		//uintRID := binary.BigEndian.Uint64(eightBytesRID[:])
 		retArr = append(retArr, samehada_util.Unpack8BytesToRID(eightBytesRID[:]))
 	}
-	//btidx.rwMtx.RUnlock()
+	btidx.rwMtx.RUnlock()
 
 	return retArr
 }
@@ -182,8 +182,8 @@ func (btidx *BTreeIndex) GetRangeScanIterator(start_key *tuple.Tuple, end_key *t
 		biggestKeyVal = samehada_util.EncodeValueAndRIDToDicOrderComparableVarchar(&orgEndKeyVal, &page.RID{math.MaxInt32, math.MaxUint32})
 	}
 
-	//btidx.rwMtx.RLock()
-	//defer btidx.rwMtx.RUnlock()
+	btidx.rwMtx.RLock()
+	defer btidx.rwMtx.RUnlock()
 	var smalledKeyBytes []byte
 	var biggestKeyBytes []byte