diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7307acd..3e7d8cb 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/btree/btree_node.cpp invodb/btree/btree_node.h)
+        invodb/main.h invodb/file/page_manager.cpp invodb/file/page_manager.h invodb/models/json.cpp invodb/models/json.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.h invodb/btree/btree_uuid.cpp invodb/btree/btree_uuid.h invodb/btree/btree_node.cpp)
diff --git a/invodb/btree/btree_node.cpp b/invodb/btree/btree_node.cpp
index 2991488..aca49a8 100644
--- a/invodb/btree/btree_node.cpp
+++ b/invodb/btree/btree_node.cpp
@@ -1,5 +1,18 @@
 //
-// Created by i on 2021/10/24.
+// Created by YuhangQ on 2021/10/25.
 //
 
 #include "btree_node.h"
+
+std::map<int, BTreeNodeUUID*> BTreeNodeUUID::map;
+
+BTreeNodeUUID *BTreeNodeUUID::getNode(const int &address) {
+    if(address == 0) {
+        printf("???");
+        exit(0);
+    }
+    if(map.count(address) == 0) {
+        map[address] = new BTreeNodeUUID(address);
+    }
+    return map[address];
+}
diff --git a/invodb/btree/btree_node.h b/invodb/btree/btree_node.h
index a55bb43..7709add 100644
--- a/invodb/btree/btree_node.h
+++ b/invodb/btree/btree_node.h
@@ -7,22 +7,102 @@
 
 #include <iostream>
 #include <cstring>
+#include <algorithm>
+#include <map>
+#include "file/page_manager.h"
 
 /**
- * m = 16
- * value string max 56
- * (56 + 4)*16 + 4 * 16 = 1024
+ * m = 28
+ * value string max
+ * (32 + 4)*28 + 5 = 1013
  */
 
-class BTreeNode {
+
+class BTreeNodeUUID {
 public:
-    BTreeNode() { memset(arr, 0, sizeof(arr)); }
+    static BTreeNodeUUID* getNode(const int& address);
+    BTreeNodeUUID(const int& address):address(address) {
+        clear();
+        StoragePage page = PageManager::Instance().getPage(address);
+        for(int i=0; i<28; i++) {
+            for(int j=0; j<32; j++) {
+                key[i] += page[i * 32 + j];
+            }
+        }
+        int p = 28 * 32;
+        for(int i=0; i<m+1; i++) {
+            val[i] = page.getIntStartFrom(p);
+            p += 4;
+        }
+        leaf = !page[1013];
+        parent = page.getIntStartFrom(1014);
+    }
+    bool isLeaf() {
+        return leaf;
+    }
+
+    void setLeaf(const bool& value) {
+        leaf = value;
+    }
+    void updateParent() {
+        if(isLeaf()) return;
+        for(int i=0; i<=size(); i++) {
+
+        }
+    }
+    int size() {
+        return n_size;
+    }
+    int insert(const std::string uuid) {
+        int pos = 0;
+        while(pos < n_size && uuid > key[pos]) pos++;
+        val[n_size + 1] = val[n_size];
+        for(int i=n_size; i>pos; i--) {
+            key[i] = key[i - 1];
+            val[i] = val[i - 1];
+        }
+        key[pos] = uuid;
+        n_size++;
+        return pos;
+    }
+    void print() {
+        printf("---------BTreeNode---------\n");
+        for(int i=0; i<size(); i++) {
+            printf("%s %d\n", key[i].c_str(), val[i]);
+        }
+    }
+    void clear() {
+        for(int i=0; i<m; i++) key[i].clear(), val[i] = 0;
+        n_size = 0;
+        leaf = false;
+        parent = 0;
+    }
+    int getAddress() { return address; }
+    void save() {
+        StoragePage page(address);
+        for(int i=0; i<28; i++) {
+            for(int j=0; j<32; j++) {
+                page[i * 32 + j] = key[i][j];
+            }
+        }
+        int p = 28 * 32;
+        for(int i=0; i<m+1; i++) {
+            page.setIntStartFrom(p, val[i]);
+            p += 4;
+        }
+        page[1013] = !leaf;
+        page.setIntStartFrom(1014, parent);
+        page.save();
+    }
+    static const int m = 28;
+    std::string key[m];
+    int val[m+1];
+    int parent;
 private:
-    struct NodeValue {
-        char key[56];
-        int value;
-    };
-    std::pair<char *, int> arr[127];
+    static std::map<int, BTreeNodeUUID*> map;
+    int address;
+    int n_size;
+    bool leaf;
 };
 
 #endif //INVODB_BTREE_NODE_H
diff --git a/invodb/btree/btree_uuid.cpp b/invodb/btree/btree_uuid.cpp
new file mode 100644
index 0000000..86215a5
--- /dev/null
+++ b/invodb/btree/btree_uuid.cpp
@@ -0,0 +1,159 @@
+//
+// Created by YuhangQ on 2021/10/25.
+//
+
+#include "btree_uuid.h"
+
+BTreeUUID::BTreeUUID(const int& address) {
+    root = BTreeNodeUUID::getNode(address);
+}
+
+void BTreeUUID::insert(const char *uuid, int address) {
+
+    BTreeNodeUUID* cur = root;
+    BTreeNodeUUID* parent = nullptr;
+
+    while(!cur->isLeaf()) {
+        parent = cur;
+        for(int i=0; i<cur->size(); i++) {
+            if(uuid < cur->key[i]) {
+                cur = BTreeNodeUUID::getNode(cur->val[i]);
+                break;
+            }
+            if(i == cur->size() - 1) {
+                cur = BTreeNodeUUID::getNode(cur->val[i + 1]);
+                break;
+            }
+        }
+        cur->parent = cur->getAddress();
+    }
+
+    // insert directly
+    if(cur->size() < cur->m - 1) {
+        cur->val[cur->insert(uuid)] = address;
+        cur->save();
+        return;
+    }
+
+    // split
+    split(uuid, address, parent, cur);
+}
+
+void BTreeUUID::split(std::string uuid, int address, BTreeNodeUUID *parent, BTreeNodeUUID *cur) {
+
+    cur->val[cur->insert(uuid)] = address;
+
+    BTreeNodeUUID* lLeaf = BTreeNodeUUID::getNode(PageManager::Instance().allocate());
+    BTreeNodeUUID* rLeaf = BTreeNodeUUID::getNode(PageManager::Instance().allocate());
+
+    int mid = (cur->m / 2);
+    for(int i=0; i<mid; i++) lLeaf->val[lLeaf->insert(cur->key[i])] = cur->val[i];
+    for(int i=mid; i<cur->m; i++) rLeaf->val[rLeaf->insert(cur->key[i])] = cur->val[i];
+
+    if(cur == root) {
+        BTreeNodeUUID* newRoot = BTreeNodeUUID::getNode(PageManager::Instance().allocate());
+        newRoot->insert(rLeaf->key[0]);
+        newRoot->val[0] = lLeaf->getAddress();
+        newRoot->val[1] = rLeaf->getAddress();
+        newRoot->setLeaf(false);
+        root = newRoot;
+        lLeaf->parent = rLeaf->parent = root->getAddress();
+
+        newRoot->save();
+        lLeaf->save();
+        rLeaf->save();
+    } else insertInternal(rLeaf->key[0], parent, lLeaf, rLeaf);
+}
+
+void BTreeUUID::insertInternal(std::string uuid, BTreeNodeUUID *cur, BTreeNodeUUID *lLeaf, BTreeNodeUUID *rLeaf) {
+
+    if(cur->size() < cur->m - 1) {
+        int pos = cur->insert(uuid);
+        cur->val[pos] = lLeaf->getAddress();
+        cur->val[pos+1] = rLeaf->getAddress();
+        lLeaf->parent = rLeaf->parent = root->getAddress();
+        cur->save();
+        lLeaf->save();
+        rLeaf->save();
+        return;
+    }
+    BTreeNodeUUID* newLChild = BTreeNodeUUID::getNode(PageManager::Instance().allocate());
+    BTreeNodeUUID* newRChild = BTreeNodeUUID::getNode(PageManager::Instance().allocate());
+    newLChild->setLeaf(false);
+    newRChild->setLeaf(false);
+
+    int pos = cur->insert(uuid);
+    cur->val[pos] = lLeaf->getAddress();
+    cur->val[pos+1] = rLeaf->getAddress();
+
+    int mid = cur->size() / 2;
+
+    for(int i=0; i<mid; i++) newLChild->insert(cur->key[i]);
+    for(int i=0; i<=mid; i++) newLChild->val[i] = cur->val[i];
+
+    for(int i=mid+1; i<cur->m; i++) newRChild->insert(cur->key[i]);
+    for(int i=mid+1; i<=cur->m; i++) newRChild->val[i-mid-1] = cur->val[i];
+
+    if(cur == root) {
+        BTreeNodeUUID* newRoot = BTreeNodeUUID::getNode(PageManager::Instance().allocate());
+        newRoot->insert(cur->key[mid]);
+        newRoot->val[0] = newLChild->getAddress();
+        newRoot->val[1] = newRChild->getAddress();
+        newRoot->setLeaf(false);
+        root = newRoot;
+        newLChild->parent = newRChild->parent = root->getAddress();
+
+        newRoot->save();
+        newLChild->save();
+        newRChild->save();
+
+
+    } else {
+        insertInternal(cur->key[mid], BTreeNodeUUID::getNode(cur->parent), newLChild, newRChild);
+    }
+
+}
+
+void BTreeUUID::print() {
+    innerPrint(root);
+}
+
+void BTreeUUID::innerPrint(BTreeNodeUUID *cur) {
+    if(cur == root) {
+        cnt = 0;
+    }
+    if(cur->isLeaf()) cnt += cur->size();
+    printf("---------%d(%d)count=%d&sum=%d--------\n", cur->getAddress(), cur->isLeaf(), cur->size(), cnt);
+    for(int i=0; i<cur->size(); i++) {
+        printf("%d:%s ", i, cur->key[i].substr(0, 4).c_str());
+    }
+    printf("\n");
+    for(int i=0; i<=cur->size(); i++) {
+        printf("%d:%d ", i, cur->val[i]);
+    }
+    printf("\n");
+    if(cur->isLeaf()) return;
+    for(int i=0; i<=cur->size(); i++) {
+        innerPrint(BTreeNodeUUID::getNode(cur->val[i]));
+    }
+}
+/*
+void BTreeUUID::innerInsert(BTreeNodeUUID* &p, BTreeNodeUUID* f, const char *uuid, int address) {
+    if(p == nullptr) {
+        p = new BTreeNodeUUID(PageManager::Instance().allocate());
+        p->insert(uuid, address);
+        return;
+    }
+    p->insert(uuid, address);
+    p->print();
+    // full
+    if(p->size() == p->m) {
+        int mid = p->m / 2;
+        BTreeNodeUUID* lnode = new BTreeNodeUUID(PageManager::Instance().allocate());
+        BTreeNodeUUID* rnode = new BTreeNodeUUID(PageManager::Instance().allocate());
+        for(int i=0; i<mid; i++) lnode->insert(p->link[i].key, p->link[i].value);
+        for(int i=mid; i<p->m; i++) rnode->insert(p->link[i].key, p->link[i].value);
+    }
+}
+*/
+
diff --git a/invodb/btree/btree_uuid.h b/invodb/btree/btree_uuid.h
new file mode 100644
index 0000000..4127a31
--- /dev/null
+++ b/invodb/btree/btree_uuid.h
@@ -0,0 +1,25 @@
+//
+// Created by YuhangQ on 2021/10/25.
+//
+
+#ifndef INVODB_BTREE_UUID_H
+#define INVODB_BTREE_UUID_H
+
+#include <btree/btree_node.h>
+
+class BTreeUUID {
+public:
+    BTreeUUID(const int& address);
+    ~BTreeUUID() { delete root; };
+    void insert(const char* uuid, int address);
+    void print();
+    void innerPrint(BTreeNodeUUID* cur);
+private:
+    void split(std::string uuid, int address, BTreeNodeUUID* parent, BTreeNodeUUID* cur);
+    void insertInternal(std::string uuid, BTreeNodeUUID* cur, BTreeNodeUUID* lLeaf, BTreeNodeUUID* rLeaf);
+    BTreeNodeUUID *root;
+    int cnt;
+};
+
+
+#endif //INVODB_BTREE_UUID_H
diff --git a/invodb/invodb.cpp b/invodb/invodb.cpp
deleted file mode 100644
index 73fb18e..0000000
--- a/invodb/invodb.cpp
+++ /dev/null
@@ -1,6 +0,0 @@
-//
-// Created by YuhangQ on 2021/10/9.
-//
-
-#include "invodb.h"
-
diff --git a/invodb/invodb.h b/invodb/invodb.h
deleted file mode 100644
index e2ef890..0000000
--- a/invodb/invodb.h
+++ /dev/null
@@ -1,20 +0,0 @@
-//
-// Created by YuhangQ on 2021/10/9.
-//
-
-#ifndef INVODB_INVODB_H
-#define INVODB_INVODB_H
-
-#include "models/json.h"
-#include "models/collection.h"
-
-class InvoDB {
-public:
-    Collection createCollection();
-    Collection getCollection();
-    void deleteCollection();
-
-};
-
-
-#endif //INVODB_INVODB_H
diff --git a/invodb/main.cpp b/invodb/main.cpp
index b1968f3..52e4007 100644
--- a/invodb/main.cpp
+++ b/invodb/main.cpp
@@ -5,17 +5,34 @@
 #include "main.h"
 
 int main() {
+    srand(time(NULL));
+
+    system("rm -rf test.invodb && touch test.invodb");
 
     PageManager::loadDatabase("test.invodb");
     Collection::loadCollections();
 
     PageManager& manager = PageManager::Instance();
 
-    //Collection::createCollection("hello");
-    Collection &col = Collection::getCollection("hello");
+    Collection *col;
+    try {
+       col = &Collection::getCollection("hello");
+    } catch(const char *error) {
+        Collection::createCollection("hello");
+    }
 
     JSON json("{\"hello\": 1}");
-    col.insert(json);
+    col->insert(json);
+
+
+    BTreeUUID *btree = new BTreeUUID(PageManager::Instance().allocate());
+    char uuid[32];
+    for(int i=0; i<1000; i++) {
+        generateUUID(uuid);
+        btree->insert(uuid, PageManager::Instance().allocate());
+    }
+
+    btree->print();
 
     return 0;
 }
\ No newline at end of file
diff --git a/invodb/main.h b/invodb/main.h
index 9ad4342..b4d5c0e 100644
--- a/invodb/main.h
+++ b/invodb/main.h
@@ -6,6 +6,7 @@
 #define INVODB_MAIN_H
 
 #include <iostream>
-#include "models/collection.h"
+#include <models/collection.h>
+
 
 #endif //INVODB_MAIN_H
diff --git a/invodb/models/collection.cpp b/invodb/models/collection.cpp
index bceed5e..dff3bbf 100644
--- a/invodb/models/collection.cpp
+++ b/invodb/models/collection.cpp
@@ -3,7 +3,6 @@
 //
 
 #include "collection.h"
-#include "utils/uuid.h"
 
 Collection::Collection(const std::string &name, const int &firstPage) {
     Logger::info<std::string, std::string>("load Collection: ", name);
diff --git a/invodb/models/collection.h b/invodb/models/collection.h
index 08d2b7b..b4e8ca7 100644
--- a/invodb/models/collection.h
+++ b/invodb/models/collection.h
@@ -7,11 +7,13 @@
 
 #include "file/page_manager.h"
 #include "utils/logger.h"
+#include "btree/btree_uuid.h"
 #include "json.h"
 #include <map>
 #include <set>
 #include <algorithm>
 #include <cstring>
+#include "utils/uuid.h"
 
 class Collection {
 public:
diff --git a/invodb/models/json.h b/invodb/models/json.h
index 9dbfe2c..fdff838 100644
--- a/invodb/models/json.h
+++ b/invodb/models/json.h
@@ -16,7 +16,6 @@ class JSON : public Document {
 public:
     JSON(std::string json): Document() { this->Parse(json.c_str()); }
     JSON(const char *json): Document() { this->Parse(json); }
-
     std::string ToString();
 private:
 };
diff --git a/invodb/utils/uuid.h b/invodb/utils/uuid.h
index 1c3bc63..d73c5f9 100644
--- a/invodb/utils/uuid.h
+++ b/invodb/utils/uuid.h
@@ -8,8 +8,7 @@
 #include <iostream>
 #include <string>
 
-void generateUUID(char *uuid) {
-    srand(time(NULL));
+inline void generateUUID(char *uuid) {
     for(int i=0; i<32; i++) {
         int randn = rand() % 36;
         uuid[i] = (randn < 26 ? ('a' + randn) : ('0' + (randn - 26)));