diff --git a/src/db/mem_table.rs b/src/db/mem_table.rs
index 995858d0bc7fcc812445068b1df862ce14c45213..9bc002cc10fae2d69fbf6c4418c9cffbddfb5872 100644
--- a/src/db/mem_table.rs
+++ b/src/db/mem_table.rs
@@ -1,26 +1,25 @@
 use std::rc::Rc;
 use crate::traits::comparator_trait::ComparatorTrait;
 use crate::traits::DataIterator;
+use crate::util::comparator::InternalKeyComparator;
 use crate::util::slice::Slice;
 
 use crate::util::Result;
 
-enum ValueType {
+pub enum ValueType {
     Insert,
     Deletion,
 }
 
 /// 内存表
-struct MemTable {
-
+pub struct MemTable<Cmp: ComparatorTrait> {
+    cmp: Rc<Cmp>,
 }
 
 /// 临时, 查找键
 struct LookupKey {}
 
-type MemTableRef = Rc<MemTable>;
-
-impl MemTable {
+impl <Cmp: ComparatorTrait> MemTable<Cmp> {
 
     /// 创建内存表
     ///
@@ -33,10 +32,12 @@ impl MemTable {
     /// # Examples
     ///
     /// ```
-    /// let mt = MemTable::create(comp);
+    /// let mt = MemTable::create(cmp);
     /// ```
-    pub fn create(_comparator: Rc<Box<dyn ComparatorTrait>>) -> Self {
-        todo!()
+    pub fn create(cmp: Rc<Cmp>) -> Self {
+        Self {
+            cmp,
+        }
     }
 
     /// 返回该表使用的内存近似值
@@ -66,7 +67,7 @@ impl MemTable {
     }
 
     /// 通过 key 查找结果
-    pub fn get(&self, key: &LookupKey) -> Result<Option<Slice>> {
+    pub fn get(&self, _key: &LookupKey) -> Result<Option<Slice>> {
         todo!()
     }
 
diff --git a/src/db/mod.rs b/src/db/mod.rs
index 4e9b202d7c316ba34b846a2689ed69ea7fbf4a03..d429a3c4b326139c56ecec5dc00b7a650fd23423 100644
--- a/src/db/mod.rs
+++ b/src/db/mod.rs
@@ -1,5 +1,15 @@
+use crate::db::skip_list::SkipList;
+use crate::db::mem_table::MemTable;
+use crate::util::comparator::{BytewiseComparatorImpl, InternalKeyComparator};
+use crate::util::slice::Slice;
+
 pub mod log_writer;
 pub mod log_reader;
 mod log_wr_test;
 pub mod skip_list;
-mod mem_table;
\ No newline at end of file
+pub mod mem_table;
+
+/// 默认调表
+pub type DefaultSkipList = SkipList<Slice, BytewiseComparatorImpl>;
+/// 默认内存表
+pub type DefaultMemTable = MemTable<InternalKeyComparator>;
\ No newline at end of file
diff --git a/src/db/skip_list.rs b/src/db/skip_list.rs
index 725dfe05ab8a4a41d9c5ded367137b4383ea69d1..144c0b60f26f215d4c7065a134c631bdf964f433 100644
--- a/src/db/skip_list.rs
+++ b/src/db/skip_list.rs
@@ -1,21 +1,28 @@
 use std::rc::Rc;
+
 use crate::traits::comparator_trait::ComparatorTrait;
 use crate::util::Arena;
-use crate::util::slice::Slice;
+use crate::util::comparator::BytewiseComparatorImpl;
 use crate::util::Result;
+use crate::util::slice::Slice;
 
-pub struct SkipList<T> {
-    node: Node<T>
-}
-
+// todo
 struct Node<T> {
     value: T,
 }
 
-impl <T> SkipList<T> {
+pub struct SkipList<T, It: ComparatorTrait> {
+    node: Option<Node<T>>,
+    comp: Rc<It>,
+}
 
-    pub fn create(_comparator: Rc<Box<dyn ComparatorTrait>>, _arena: Rc<Arena>) -> Self {
-        todo!()
+impl<T, It: ComparatorTrait> SkipList<T, It> {
+
+    pub fn create(comparator: Rc<It>, _arena: Rc<Arena>) -> Self {
+        Self {
+            node: None,
+            comp: comparator,
+        }
     }
 
     pub fn insert(&mut self, _seq_no: usize, _key: &Slice) -> Result<()> {
@@ -29,5 +36,4 @@ impl <T> SkipList<T> {
     pub fn get_max_height(&self) -> usize {
         todo!()
     }
-
 }
\ No newline at end of file
diff --git a/src/traits/mod.rs b/src/traits/mod.rs
index 45c7ee32368446a52d4e8ac8666817e0171e61df..47c662e6d0774ea213fb7838379a7ae1e0073d24 100644
--- a/src/traits/mod.rs
+++ b/src/traits/mod.rs
@@ -4,4 +4,5 @@ pub mod comparator_trait;
 pub mod coding_trait;
 pub mod filter_policy_trait;
 
-pub use iterator::DataIterator;
\ No newline at end of file
+use std::rc::Rc;
+pub use iterator::DataIterator;
diff --git a/src/util/mod.rs b/src/util/mod.rs
index cb17c906aae7e8102a3beda4c8cc2dee0d572ff7..2808228e6b8354af1171e11930190dad186e3f4b 100644
--- a/src/util/mod.rs
+++ b/src/util/mod.rs
@@ -1,7 +1,9 @@
+use std::rc::Rc;
 use std::result;
 
 pub use arena::Arena;
 
+use crate::util::comparator::{BytewiseComparatorImpl, InternalKeyComparator};
 use crate::util::status::Status;
 
 /// 常量定义
@@ -25,12 +27,12 @@ mod bloom_filter_test;
 pub mod filter_policy;
 mod filter_policy_test;
 
-/// 定义别名
-pub type Result<T> = result::Result<T, Status>;
-
 pub mod histogram;
 mod histogram_test;
 mod hash;
 mod hash_test;
 mod mutex_lock;
 mod mutex_lock_test;
+
+/// 定义别名
+pub type Result<T> = result::Result<T, Status>;