diff --git a/invodb/btree/btree.h b/invodb/btree/btree.h
index 20eed9e..443d38f 100644
--- a/invodb/btree/btree.h
+++ b/invodb/btree/btree.h
@@ -15,6 +15,7 @@ public:
     void insert(const KT &key, const int &value);
     void update(const KT &key, const int &value);
     void remove(const KT &key);
+
     bool exists(const KT &key);
     int getNodeSize();
     int find(const KT &key);
@@ -337,7 +338,7 @@ void BTree<KT, K_SIZE>::split(const KT &key, int address, int parentAdd, int cur
         curRight->save();
     }
 
-    cur->release();
+
 
     if(cur->address == root) {
 //        auto newRoot = BTreeNode<M_SIZE, KT, K_SIZE>::getNode(PageManager::Instance().allocate());
@@ -370,6 +371,7 @@ void BTree<KT, K_SIZE>::split(const KT &key, int address, int parentAdd, int cur
         lLeaf->save();
         rLeaf->save();
         insertInternal(rLeaf->keySet[0], cur->parent, lLeaf->address, rLeaf->address);
+        cur->release();
     }
 }
 
@@ -464,7 +466,7 @@ void BTree<KT, K_SIZE>::insertInternal(const KT &key, int curAdd, int lLeafAdd,
         child->save();
     }
 
-    cur->release();
+
 
     if(cur->address == root) {
 //        auto newRoot = BTreeNode<M_SIZE, KT, K_SIZE>::getNode(PageManager::Instance().allocate());
@@ -499,6 +501,7 @@ void BTree<KT, K_SIZE>::insertInternal(const KT &key, int curAdd, int lLeafAdd,
         newLChild->save();
         newRChild->save();
         insertInternal(cur->keySet[mid], cur->parent, newLChild->address, newRChild->address);
+        cur->release();
     }
 }
 
diff --git a/invodb/btree/node.h b/invodb/btree/node.h
index c99c615..354d576 100644
--- a/invodb/btree/node.h
+++ b/invodb/btree/node.h
@@ -16,6 +16,7 @@
 template<int M_SIZE, typename KT, int K_SIZE>
 class BTreeNode {
 public:
+    BTreeNode(const int& address);
     static std::shared_ptr<BTreeNode<M_SIZE, KT, K_SIZE>> getNode(const int &index);
     static BTreeNode<M_SIZE, KT, K_SIZE>* release(const int &index);
     int insert(KT const &key);
@@ -50,8 +51,6 @@ public:
     bool leaf;
     int size;
     int address;
-private:
-    BTreeNode(const int& address);
 };
 
 template<int M_SIZE, typename KT, int K_SIZE>
@@ -95,17 +94,7 @@ std::shared_ptr<BTreeNode<M_SIZE, KT, K_SIZE>> BTreeNode<M_SIZE, KT, K_SIZE>::ge
     if(index == 0) {
         throw "invalid address!";
     }
-    return std::make_shared<BTreeNode<M_SIZE, KT, K_SIZE>>( BTreeNode<M_SIZE, KT, K_SIZE>(index));
-    static LRUCache<int, BTreeNode<M_SIZE, KT, K_SIZE>> cache(1000000);
-    if(!cache.exist(index)) {
-        auto p = std::make_shared<BTreeNode<M_SIZE, KT, K_SIZE>>( BTreeNode<M_SIZE, KT, K_SIZE>(index));
-        cache.put(index, p);
-        return p;
-    } else {
-        auto p = cache.get(index);
-        cache.put(index, p);
-        return p;
-    }
+    return std::make_shared<BTreeNode<M_SIZE, KT, K_SIZE>>(index);
 }
 
 template<int M_SIZE, typename KT, int K_SIZE>
diff --git a/invodb/file/page_manager.cpp b/invodb/file/page_manager.cpp
index 67349d8..1438625 100644
--- a/invodb/file/page_manager.cpp
+++ b/invodb/file/page_manager.cpp
@@ -5,7 +5,7 @@
 #include "page_manager.h"
 #include "btree/list.h"
 
-List<int, 4>* PageManager::freeList = new List<int, 4>(1);
+
 
 int PageManager::loadDatabase(const char *filename) {
     Instance().stream.open(filename);
@@ -19,60 +19,76 @@ int PageManager::loadDatabase(const char *filename) {
     return 0;
 }
 
-StoragePage PageManager::getPage(const int &index) {
+std::shared_ptr<StoragePage> PageManager::getPage(const int &index) {
 
-    /*
     if(cache.exist(index)) {
         return cache.get(index);
     }
-     */
 
-    StoragePage page(index);
+    auto page = std::make_shared<StoragePage>(index);
     // 调整指针位置
     stream.clear();
-    stream.seekg(index * 1024);
-    stream.read(page, 1024);
+    stream.seekg((long long)index * 1024);
+    stream.read(*page, 1024);
     return page;
 }
 
 void PageManager::setPage(const int &index, const StoragePage &page) {
-    //cache.put(index, page);
+    cache.put(index, std::make_shared<StoragePage>(page));
+
     stream.clear();
-    stream.seekg(index * 1024);
+    stream.seekg((long long)index * 1024);
     stream.write(page, 1024);
 }
 
 int PageManager::allocate() {
+
+//     try to allocate from free block list
+    auto page = getPage(0);
+    int index =  page->getIntStartFrom(0);
+    if(index != 0) {
+        auto allocatePage = getPage(index);
+
+        page->setIntStartFrom(0, allocatePage->next());
+        // reset
+        allocatePage->clear();
+        allocatePage->save();
+        page->save();
+        //printf("allocate: %d\n", index);
+        return index;
+    }
+
+
+    // allocate block at the end
     stream.seekp(0, std::ios::end);
-    int index = stream.tellp() / 1024;
+    index = stream.tellp() / 1024;
     setPage(index, StoragePage(index));
     return index;
 }
 
 void PageManager::release(const int &index, const bool &next) {
+    auto page = getPage(0);
+    int head = page->getIntStartFrom(0);
+    auto releasePage = getPage(index);
+    releasePage->setNext(head);
+    page->setIntStartFrom(0, releasePage->getAddress());
+    page->save();
+    releasePage->save();
+    //printf("release: %d\n", index);
 
-    return;
-    auto page = getPage(index);
-    freeList->insert(page.getAddress());
-    if(next) {
-        while(page.next()) {
-            freeList->insert(page.next());
-            page = getPage(page.next());
-        }
-    }
 }
 
 nlohmann::json PageManager::readJSONFromFile(const int &index) {
     std::string content;
 
-    StoragePage page = getPage(index);
+    auto page = getPage(index);
     while(true) {
         for(int i=0; i<1016; i++) {
-            if(page[i] == '\0') break;
-            content.push_back(page[i]);
+            if((*page)[i] == '\0') break;
+            content.push_back((*page)[i]);
         }
-        if(page.next() == 0) break;
-        page = getPage(page.next());
+        if(page->next() == 0) break;
+        page = getPage(page->next());
     }
 
     return nlohmann::json::parse(content);
@@ -82,22 +98,22 @@ int PageManager::saveJSONToFile(const nlohmann::json& json) {
     std::string content = json.dump();
     int size = content.size();
 
-    StoragePage page = getPage(allocate());
-    int res = page.getAddress();
+    auto page = getPage(allocate());
+    int res = page->getAddress();
     int p = 0;
     while(p < size) {
         int len = std::min(size - p, 1016);
-        page.setStartFrom(0, &content.c_str()[p], len);
-        page.save();
+        page->setStartFrom(0, &content.c_str()[p], len);
+        page->save();
         p += len;
         if(p < size) {
             int newPage = allocate();
-            int lastPage = page.getAddress();
-            page.setNext(newPage);
-            page.save();
+            int lastPage = page->getAddress();
+            page->setNext(newPage);
+            page->save();
             page = getPage(newPage);
-            page.setLast(lastPage);
-            page.save();
+            page->setLast(lastPage);
+            page->save();
         }
     }
     return res;
diff --git a/invodb/file/page_manager.h b/invodb/file/page_manager.h
index d8f48f5..824ca49 100644
--- a/invodb/file/page_manager.h
+++ b/invodb/file/page_manager.h
@@ -23,19 +23,18 @@ public:
         return instance;
     }
     static int loadDatabase(const char *filename);
-    StoragePage getPage(const int &index);
+    std::shared_ptr<StoragePage> getPage(const int &index);
     void setPage(const int &index, const StoragePage &page);
     int allocate();
     void release(const int &index, const bool &next = true);
     int saveJSONToFile(const nlohmann::json& json);
     nlohmann::json readJSONFromFile(const int &index);
 private:
-    static List<int, 4> *freeList;
     std::map<int, StoragePage> map;
     std::fstream stream;
     LRUCache<int, StoragePage> cache;
     // 私有化实现单例
-    PageManager():cache(LRUCache<int, StoragePage>(1000)) {}
+    PageManager():cache(LRUCache<int, StoragePage>(100000)) {}
     ~PageManager() {}
     PageManager(const PageManager&);
     PageManager& operator=(const PageManager&);
diff --git a/invodb/file/storage_page.cpp b/invodb/file/storage_page.cpp
index fc2d88f..fd9f85b 100644
--- a/invodb/file/storage_page.cpp
+++ b/invodb/file/storage_page.cpp
@@ -73,4 +73,8 @@ void StoragePage::setStartFrom(const int &index, const void *content, int size)
     for(int i=0; i<size; i++) {
         page[index+i] = ((const char *)content)[i];
     }
-}
\ No newline at end of file
+}
+
+void StoragePage::clear() {
+    memset(page, 0, sizeof(page));
+}
diff --git a/invodb/file/storage_page.h b/invodb/file/storage_page.h
index 3d563d7..20cf512 100644
--- a/invodb/file/storage_page.h
+++ b/invodb/file/storage_page.h
@@ -20,6 +20,7 @@ public:
     int last();
     void setLast(const int& lastPage);
     void save();
+    void clear();
     int getIntStartFrom(const int &index);
     void setIntStartFrom(const int &index, const int &value);
     void setDoubleStartFrom(const int &index, const double &value);
diff --git a/invodb/main.cpp b/invodb/main.cpp
index d05392a..efb8fe0 100644
--- a/invodb/main.cpp
+++ b/invodb/main.cpp
@@ -13,7 +13,7 @@ int main() {
     //srand(t);
     printf("seed: %d\n", t);
 
-    //system("rm -rf test.invodb && touch test.invodb");
+    system("rm -rf test.invodb && touch test.invodb");
 
     PageManager::loadDatabase("test.invodb");
 
@@ -41,7 +41,7 @@ int main() {
 //        col->insert(json);
 //    }
 
-    col->test();
+    //col->test();
 
 
 //    nlohmann::json j = nlohmann::json::parse(R"(
@@ -57,10 +57,7 @@ int main() {
 //}
 //    )");
 
-
-    //testAndBenchmark(100000);
-
-
+    testAndBenchmark(50000);
 
     return 0;
 }
@@ -78,6 +75,10 @@ void testAndBenchmark(int n) {
     for(int i=0; i<n; i++) {
         int opt = rand() % 4;
 
+        if(i%(n/100) == 0) {
+            printf("[%d/%d] eeeeee\n", i, n);
+        }
+
         // insert
         if(opt <= 1) {
             std::string uuid = generateUUID();