diff --git a/bustubx/src/common/scalar.rs b/bustubx/src/common/scalar.rs
index 1d7a099..003b2c8 100644
--- a/bustubx/src/common/scalar.rs
+++ b/bustubx/src/common/scalar.rs
@@ -41,6 +41,13 @@ impl ScalarValue {
             Self::Int16(Some(v)) => v.to_be_bytes().to_vec(),
             Self::Int32(Some(v)) => v.to_be_bytes().to_vec(),
             Self::Int64(Some(v)) => v.to_be_bytes().to_vec(),
+
+            // TODO fixme
+            Self::Boolean(None) => vec![0u8; 1],
+            Self::Int8(None) => vec![0u8; 1],
+            Self::Int16(None) => vec![0u8; 2],
+            Self::Int32(None) => vec![0u8; 4],
+            Self::Int64(None) => vec![0u8; 8],
             _ => unimplemented!(),
         }
     }
diff --git a/bustubx/src/storage/index_page.rs b/bustubx/src/storage/index_page.rs
index ff7ad1c..594d14e 100644
--- a/bustubx/src/storage/index_page.rs
+++ b/bustubx/src/storage/index_page.rs
@@ -359,7 +359,7 @@ impl BPlusTreeInternalPage {
         if self.current_size == 0 {
             buf[12..BUSTUBX_PAGE_SIZE].fill(0);
         } else {
-            let key_size = self.array[0].0.data.len();
+            let key_size = self.array[0].0.to_bytes().len();
             let value_size = size_of::<PageId>();
             let kv_size = key_size + value_size;
             for i in 0..self.current_size {
@@ -465,7 +465,7 @@ impl BPlusTreeLeafPage {
         if self.current_size == 0 {
             buf[16..BUSTUBX_PAGE_SIZE].fill(0);
         } else {
-            let key_size = self.array[0].0.data.len();
+            let key_size = self.array[0].0.to_bytes().len();
             let value_size = size_of::<Rid>();
             let kv_size = key_size + value_size;
             for i in 0..self.current_size {
@@ -628,7 +628,7 @@ mod tests {
         assert_eq!(new_page.max_size, 5);
         assert_eq!(
             new_page.array[0].0.data,
-            vec![ScalarValue::Int8(None), ScalarValue::Int16(None)]
+            vec![ScalarValue::Int8(Some(0)), ScalarValue::Int16(Some(0))]
         );
         assert_eq!(new_page.array[0].1, 0);
         assert_eq!(new_page.array[1].0.data, vec![1i8.into(), 1i16.into()]);
diff --git a/bustubx/src/storage/table_heap.rs b/bustubx/src/storage/table_heap.rs
index c50c1ba..968e707 100644
--- a/bustubx/src/storage/table_heap.rs
+++ b/bustubx/src/storage/table_heap.rs
@@ -272,8 +272,8 @@ mod tests {
             &Tuple::new(schema.clone(), vec![3i8.into(), 3i16.into()]),
         );
         assert_eq!(table_heap.first_page_id, 0);
-        assert_eq!(table_heap.last_page_id, 1);
-        assert_eq!(table_heap.buffer_pool_manager.replacer.size(), 2);
+        assert_eq!(table_heap.last_page_id, 0);
+        assert_eq!(table_heap.buffer_pool_manager.replacer.size(), 1);
     }
 
     #[test]
@@ -323,7 +323,7 @@ mod tests {
         assert_eq!(meta.insert_txn_id, 1);
         assert_eq!(meta.delete_txn_id, 2);
         assert_eq!(meta.is_deleted, true);
-        assert_eq!(table_heap.buffer_pool_manager.replacer.size(), 2);
+        assert_eq!(table_heap.buffer_pool_manager.replacer.size(), 1);
     }
 
     #[test]
@@ -385,7 +385,7 @@ mod tests {
         assert_eq!(meta, meta3);
         assert_eq!(tuple.data, vec![3i8.into(), 3i16.into()]);
 
-        assert_eq!(table_heap.buffer_pool_manager.replacer.size(), 2);
+        assert_eq!(table_heap.buffer_pool_manager.replacer.size(), 1);
     }
 
     #[test]
@@ -452,6 +452,6 @@ mod tests {
 
         assert!(iterator.next(&mut table_heap).is_none());
 
-        assert_eq!(table_heap.buffer_pool_manager.replacer.size(), 2);
+        assert_eq!(table_heap.buffer_pool_manager.replacer.size(), 1);
     }
 }
diff --git a/bustubx/src/storage/table_page.rs b/bustubx/src/storage/table_page.rs
index 00fd514..cf3b799 100644
--- a/bustubx/src/storage/table_page.rs
+++ b/bustubx/src/storage/table_page.rs
@@ -59,13 +59,13 @@ impl TablePage {
         };
 
         // Check if the current slot has enough space for the new tuple. Return None if not.
-        if slot_end_offset < tuple.data.len() as u16 {
+        if slot_end_offset < tuple.to_bytes().len() as u16 {
             return None;
         }
 
         // Calculate the insertion offset for the new tuple by subtracting its data length
         // from the ending offset of the current slot.
-        let tuple_offset = slot_end_offset - tuple.data.len() as u16;
+        let tuple_offset = slot_end_offset - tuple.to_bytes().len() as u16;
 
         // Calculate the minimum valid tuple insertion offset, including the table page header size,
         // the total size of each tuple info (existing tuple infos and newly added tuple info).
@@ -86,7 +86,7 @@ impl TablePage {
 
         // Store tuple information including offset, length, and metadata.
         self.tuple_info
-            .push((tuple_offset, tuple.data.len() as u16, meta.clone()));
+            .push((tuple_offset, tuple.to_bytes().len() as u16, meta.clone()));
 
         // only check
         assert_eq!(tuple_id, self.tuple_info.len() as u16 - 1);
@@ -97,7 +97,7 @@ impl TablePage {
         }
 
         // Copy the tuple's data into the appropriate position within the page's data buffer.
-        self.data[tuple_offset as usize..(tuple_offset + tuple.data.len() as u16) as usize]
+        self.data[tuple_offset as usize..(tuple_offset + tuple.to_bytes().len() as u16) as usize]
             .copy_from_slice(&tuple.to_bytes());
         return Some(tuple_id);
     }