diff --git a/Cargo.toml b/Cargo.toml
index fe521da..7d50ded 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "kip_db"
-version = "0.1.2-alpha.18"
+version = "0.1.2-alpha.19"
 edition = "2021"
 authors = ["Kould <kould2333@gmail.com>"]
 description = "轻量级、异步 基于LSM Leveled Compaction K-V数据库"
diff --git a/examples/mvcc.rs b/examples/mvcc.rs
index 57431e7..3411e34 100644
--- a/examples/mvcc.rs
+++ b/examples/mvcc.rs
@@ -12,7 +12,7 @@ async fn main() -> Result<(), KernelError> {
     let kip_storage = KipStorage::open_with_config(config).await?;
 
     println!("New Transaction");
-    let mut tx = kip_storage.new_transaction(CheckType::None).await;
+    let mut tx = kip_storage.new_transaction(CheckType::Optimistic).await;
 
     println!("Set KeyValue after the transaction -> (key_1, value_1)");
     kip_storage
diff --git a/examples/scan_read.rs b/examples/scan_read.rs
index df48cb5..0b3f5e6 100644
--- a/examples/scan_read.rs
+++ b/examples/scan_read.rs
@@ -36,7 +36,7 @@ async fn main() -> Result<(), KernelError> {
         .await?;
 
     println!("New Transaction");
-    let tx = kip_storage.new_transaction(CheckType::None).await;
+    let tx = kip_storage.new_transaction(CheckType::Optimistic).await;
 
     println!("Iter without key_3 By Transaction:");
     let mut iter = tx.iter(Bound::Unbounded, Bound::Excluded(b"key_3"))?;
diff --git a/src/kernel/lsm/mvcc.rs b/src/kernel/lsm/mvcc.rs
index fd7f2db..d9c9457 100644
--- a/src/kernel/lsm/mvcc.rs
+++ b/src/kernel/lsm/mvcc.rs
@@ -30,7 +30,6 @@ unsafe impl Sync for BufPtr {}
 struct BufPtr(NonNull<Vec<KeyValue>>);
 
 pub enum CheckType {
-    None,
     Optimistic,
 }
 
@@ -89,7 +88,6 @@ impl Transaction {
             let batch_data = buf.into_iter().collect_vec();
 
             match self.check_type {
-                CheckType::None => (),
                 CheckType::Optimistic => {
                     if self
                         .mem_table()
@@ -350,7 +348,7 @@ mod tests {
             kv_store.set(kv.0.clone(), kv.1.clone()).await?;
         }
 
-        let mut tx_1 = kv_store.new_transaction(CheckType::None).await;
+        let mut tx_1 = kv_store.new_transaction(CheckType::Optimistic).await;
 
         for kv in vec_kv.iter().take(times).skip(100) {
             tx_1.set(kv.0.clone(), kv.1.clone());
@@ -402,7 +400,7 @@ mod tests {
         let config = Config::new(temp_dir.into_path()).major_threshold_with_sst_size(4);
         let kv_store = KipStorage::open_with_config(config).await?;
 
-        let mut tx_1 = kv_store.new_transaction(CheckType::None).await;
+        let mut tx_1 = kv_store.new_transaction(CheckType::Optimistic).await;
         let mut tx_2 = kv_store.new_transaction(CheckType::Optimistic).await;
 
         tx_1.set(Bytes::from("same_key"), Bytes::new());