diff --git a/bustubx/src/catalog/catalog.rs b/bustubx/src/catalog/catalog.rs
index 6476858..62be4d3 100644
--- a/bustubx/src/catalog/catalog.rs
+++ b/bustubx/src/catalog/catalog.rs
@@ -313,7 +313,6 @@ impl Catalog {
                 b_plus_tree_index.root_page_id.load(Ordering::SeqCst).into(),
             ],
         );
-        println!("LWZTEST tuple: {:?}", tuple);
         indexes_table
             .table
             .insert_tuple(&EMPTY_TUPLE_META, &tuple)?;
diff --git a/bustubx/src/execution/physical_plan/index_scan.rs b/bustubx/src/execution/physical_plan/index_scan.rs
index 7eda7a4..6922b7f 100644
--- a/bustubx/src/execution/physical_plan/index_scan.rs
+++ b/bustubx/src/execution/physical_plan/index_scan.rs
@@ -48,7 +48,6 @@ impl VolcanoExecutor for PhysicalIndexScan {
     }
 
     fn next(&self, context: &mut ExecutionContext) -> BustubxResult<Option<Tuple>> {
-        println!("LWZTEST index_scan");
         let mut guard = self.iterator.lock().unwrap();
         let Some(iterator) = &mut *guard else {
             return Err(BustubxError::Execution(
diff --git a/bustubx/src/execution/physical_plan/seq_scan.rs b/bustubx/src/execution/physical_plan/seq_scan.rs
index d9f00ef..8424c29 100644
--- a/bustubx/src/execution/physical_plan/seq_scan.rs
+++ b/bustubx/src/execution/physical_plan/seq_scan.rs
@@ -34,7 +34,6 @@ impl VolcanoExecutor for PhysicalSeqScan {
     }
 
     fn next(&self, _context: &mut ExecutionContext) -> BustubxResult<Option<Tuple>> {
-        println!("LWZTEST seq_scan");
         let Some(iterator) = &mut *self.iterator.lock().unwrap() else {
             return Err(BustubxError::Execution(
                 "table iterator not created".to_string(),
diff --git a/bustubx/src/storage/codec/scalar.rs b/bustubx/src/storage/codec/scalar.rs
index 54d9977..0a217e2 100644
--- a/bustubx/src/storage/codec/scalar.rs
+++ b/bustubx/src/storage/codec/scalar.rs
@@ -20,6 +20,9 @@ impl ScalarValueCodec {
             ScalarValue::Float32(Some(v)) => CommonCodec::encode_f32(*v),
             ScalarValue::Float64(Some(v)) => CommonCodec::encode_f64(*v),
             ScalarValue::Varchar(Some(v)) => {
+                if v.len() > u16::MAX as usize {
+                    panic!("Varchar length is greater than u16::Max")
+                }
                 let mut bytes = vec![];
                 bytes.extend(CommonCodec::encode_u16(v.len() as u16));
                 bytes.extend(CommonCodec::encode_string(v));
diff --git a/bustubx/src/storage/codec/tuple.rs b/bustubx/src/storage/codec/tuple.rs
index 6e9504c..e737f6c 100644
--- a/bustubx/src/storage/codec/tuple.rs
+++ b/bustubx/src/storage/codec/tuple.rs
@@ -25,7 +25,7 @@ impl TupleCodec {
     pub fn decode(bytes: &[u8], schema: SchemaRef) -> BustubxResult<DecodedData<Tuple>> {
         let mut total_offset = 0;
 
-        let null_map_bytes = (schema.column_count() >> 3) + 1;
+        let null_map_bytes = schema.column_count().div_ceil(8);
         let null_map = DynamicBitmap::from_bytes(&bytes[0..null_map_bytes]);
         total_offset += null_map_bytes;
         let mut bytes = &bytes[null_map_bytes..];
@@ -67,7 +67,12 @@ mod tests {
         ]));
         let tuple = Tuple::new(
             schema.clone(),
-            vec![true.into(), ScalarValue::Int32(None), 1234u64.into(), "aabb".to_string().into()],
+            vec![
+                true.into(),
+                ScalarValue::Int32(None),
+                1234u64.into(),
+                "aabb".to_string().into(),
+            ],
         );
         let new_tuple = TupleCodec::decode(&TupleCodec::encode(&tuple), schema)
             .unwrap()