diff --git a/CMakeLists.txt b/CMakeLists.txt
index 89f53c3..7307acd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,4 +8,4 @@ include_directories(./invodb)
 
 add_executable(InvoDB
         invodb/main.cpp
-        invodb/main.h invodb/file/page_manager.cpp invodb/file/page_manager.h invodb/models/json.cpp invodb/models/json.h invodb/invodb.cpp invodb/invodb.h invodb/models/collection.cpp invodb/models/collection.h invodb/file/storage_page.cpp invodb/file/storage_page.h invodb/utils/logger.h invodb/utils/uuid.h)
+        invodb/main.h invodb/file/page_manager.cpp invodb/file/page_manager.h invodb/models/json.cpp invodb/models/json.h invodb/invodb.cpp invodb/invodb.h invodb/models/collection.cpp invodb/models/collection.h invodb/file/storage_page.cpp invodb/file/storage_page.h invodb/utils/logger.h invodb/utils/uuid.h invodb/btree/btree_node.cpp invodb/btree/btree_node.h)
diff --git a/invodb/btree/btree_node.cpp b/invodb/btree/btree_node.cpp
new file mode 100644
index 0000000..2991488
--- /dev/null
+++ b/invodb/btree/btree_node.cpp
@@ -0,0 +1,5 @@
+//
+// Created by i on 2021/10/24.
+//
+
+#include "btree_node.h"
diff --git a/invodb/btree/btree_node.h b/invodb/btree/btree_node.h
new file mode 100644
index 0000000..a55bb43
--- /dev/null
+++ b/invodb/btree/btree_node.h
@@ -0,0 +1,28 @@
+//
+// Created by i on 2021/10/24.
+//
+
+#ifndef INVODB_BTREE_NODE_H
+#define INVODB_BTREE_NODE_H
+
+#include <iostream>
+#include <cstring>
+
+/**
+ * m = 16
+ * value string max 56
+ * (56 + 4)*16 + 4 * 16 = 1024
+ */
+
+class BTreeNode {
+public:
+    BTreeNode() { memset(arr, 0, sizeof(arr)); }
+private:
+    struct NodeValue {
+        char key[56];
+        int value;
+    };
+    std::pair<char *, int> arr[127];
+};
+
+#endif //INVODB_BTREE_NODE_H
diff --git a/invodb/file/storage_page.cpp b/invodb/file/storage_page.cpp
index a6612d3..784dd2b 100644
--- a/invodb/file/storage_page.cpp
+++ b/invodb/file/storage_page.cpp
@@ -47,7 +47,6 @@ void StoragePage::setStringStartFrom(const int &index, const char *str) {
     for(int i=0; i<strlen(str); i++) {
         page[index+i] = str[i];
     }
-
 }
 
 void StoragePage::save() {
diff --git a/invodb/main.cpp b/invodb/main.cpp
index f383fd1..b1968f3 100644
--- a/invodb/main.cpp
+++ b/invodb/main.cpp
@@ -5,12 +5,12 @@
 #include "main.h"
 
 int main() {
+
     PageManager::loadDatabase("test.invodb");
     Collection::loadCollections();
 
     PageManager& manager = PageManager::Instance();
 
-
     //Collection::createCollection("hello");
     Collection &col = Collection::getCollection("hello");
 
diff --git a/invodb/models/collection.cpp b/invodb/models/collection.cpp
index b8afb83..bceed5e 100644
--- a/invodb/models/collection.cpp
+++ b/invodb/models/collection.cpp
@@ -11,17 +11,15 @@ Collection::Collection(const std::string &name, const int &firstPage) {
 
 void Collection::insert(JSON &json) {
 
-    if(!json.HasMember(" __Invo_ID__")) {
-        std::string uuid = generateUUID();
+    if(!json.HasMember("__Invo_ID__")) {
+        char uuid[32];
+        generateUUID(uuid);
         Document::AllocatorType &allocator = json.GetAllocator();
         Value invoid (kStringType);
-        invoid.SetString(uuid.c_str(), 3);
-        json.AddMember(" __Invo_ID__", invoid, allocator);
+        invoid.SetString(uuid, 32);
+        json.AddMember("__Invo_ID__", invoid, allocator);
     }
-
-
-
-    Logger::info<std::string>(json.ToString());
+    Logger::info<std::string, std::string>("INSERT ", json.ToString());
 }
 
 
diff --git a/invodb/utils/logger.h b/invodb/utils/logger.h
index 22d2afd..b9f9ab3 100644
--- a/invodb/utils/logger.h
+++ b/invodb/utils/logger.h
@@ -10,10 +10,8 @@
 
 class Logger {
 public:
-
     template<typename T>
     static void info(const T& msg);
-
     template<typename T, typename K>
     static void info(const T& first, const K& second);
     template<typename T>
diff --git a/invodb/utils/uuid.h b/invodb/utils/uuid.h
index 8c6d8e8..1c3bc63 100644
--- a/invodb/utils/uuid.h
+++ b/invodb/utils/uuid.h
@@ -8,16 +8,12 @@
 #include <iostream>
 #include <string>
 
-std::string generateUUID() {
+void generateUUID(char *uuid) {
     srand(time(NULL));
-    std::string uuid;
     for(int i=0; i<32; i++) {
         int randn = rand() % 36;
-        //0~35;
-        uuid += (randn < 26 ? ('a' + randn) : ('0' + (randn - 26)));
+        uuid[i] = (randn < 26 ? ('a' + randn) : ('0' + (randn - 26)));
     }
-    std::cout << uuid << std::endl;
-    return uuid;
 }
 
 #endif //INVODB_UUID_H