diff --git a/1.patch b/1.patch
deleted file mode 100644
index 5eb5986fd0a2f0c958df3f5cd0848d579998e598..0000000000000000000000000000000000000000
--- a/1.patch
+++ /dev/null
@@ -1,797 +0,0 @@
-diff --git a/src/observer/sql/expr/expression.h b/src/observer/sql/expr/expression.h
-index c586bf2..59b1750 100644
---- a/src/observer/sql/expr/expression.h
-+++ b/src/observer/sql/expr/expression.h
-@@ -14,6 +14,7 @@ See the Mulan PSL v2 for more details. */
- 
- #pragma once
- 
-+#include <string.h>
- #include "storage/common/field.h"
- #include "sql/expr/tuple_cell.h"
- 
-@@ -79,7 +80,11 @@ class ValueExpr : public Expression
- public:
-   ValueExpr() = default;
-   ValueExpr(const Value &value) : tuple_cell_(value.type, (char *)value.data)
--  {}
-+  {
-+    if (value.type == CHARS) {
-+      tuple_cell_.set_length(strlen((const char *)value.data));
-+    }
-+  }
- 
-   virtual ~ValueExpr() = default;
- 
-diff --git a/src/observer/sql/expr/tuple.h b/src/observer/sql/expr/tuple.h
-index 07c33c7..7efed51 100644
---- a/src/observer/sql/expr/tuple.h
-+++ b/src/observer/sql/expr/tuple.h
-@@ -115,6 +115,7 @@ public:
-     const FieldMeta *field_meta = field_expr->field().meta();
-     cell.set_type(field_meta->type());
-     cell.set_data(this->record_->data() + field_meta->offset());
-+    cell.set_length(field_meta->len());
-     return RC::SUCCESS;
-   }
- 
-diff --git a/src/observer/sql/expr/tuple_cell.cpp b/src/observer/sql/expr/tuple_cell.cpp
-index 9ccd3d3..c878b31 100644
---- a/src/observer/sql/expr/tuple_cell.cpp
-+++ b/src/observer/sql/expr/tuple_cell.cpp
-@@ -27,7 +27,7 @@ void TupleCell::to_string(std::ostream &os) const
-     os << *(float *)data_;
-   } break;
-   case CHARS: {
--    for (int i = 0; i < 4; i++) { // the max length of CHARS is 4
-+    for (int i = 0; i < length_; i++) {
-       if (data_[i] == '\0') {
-         break;
-       }
-@@ -46,7 +46,7 @@ int TupleCell::compare(const TupleCell &other) const
-     switch (this->attr_type_) {
-     case INTS: return compare_int(this->data_, other.data_);
-     case FLOATS: return compare_float(this->data_, other.data_);
--    case CHARS: return compare_string(this->data_, other.data_, 4);
-+    case CHARS: return compare_string(this->data_, this->length_, other.data_, other.length_);
-     default: {
-       LOG_WARN("unsupported type: %d", this->attr_type_);
-     }
-diff --git a/src/observer/sql/expr/tuple_cell.h b/src/observer/sql/expr/tuple_cell.h
-index 89170f2..faf3996 100644
---- a/src/observer/sql/expr/tuple_cell.h
-+++ b/src/observer/sql/expr/tuple_cell.h
-@@ -31,6 +31,7 @@ public:
-   {}
- 
-   void set_type(AttrType type) { this->attr_type_ = type; }
-+  void set_length(int length) { this->length_ = length; }
-   void set_data(char *data) { this->data_ = data; }
-   void set_data(const char *data) { this->set_data(const_cast<char *>(data)); }
- 
-@@ -43,11 +44,15 @@ public:
-     return data_;
-   }
- 
-+  int length() const { return length_; }
-+
-   AttrType attr_type() const
-   {
-     return attr_type_;
-   }
-+
- private:
-   AttrType attr_type_ = UNDEFINED;
-+  int length_ = -1;
-   char *data_ = nullptr; // real data. no need to move to field_meta.offset
- };
-diff --git a/src/observer/sql/operator/index_scan_operator.cpp b/src/observer/sql/operator/index_scan_operator.cpp
-index 1be1a37..2aad13b 100644
---- a/src/observer/sql/operator/index_scan_operator.cpp
-+++ b/src/observer/sql/operator/index_scan_operator.cpp
-@@ -36,8 +36,8 @@ RC IndexScanOperator::open()
-   }
- 
-   
--  IndexScanner *index_scanner = index_->create_scanner(left_cell_.data(), left_inclusive_,
--					       right_cell_.data(), right_inclusive_);
-+  IndexScanner *index_scanner = index_->create_scanner(left_cell_.data(), left_cell_.length(), left_inclusive_,
-+                                                       right_cell_.data(), right_cell_.length(), right_inclusive_);
-   if (nullptr == index_scanner) {
-     LOG_WARN("failed to create index scanner");
-     return RC::INTERNAL;
-diff --git a/src/observer/storage/common/condition_filter.h b/src/observer/storage/common/condition_filter.h
-index 890195a..e4b7f98 100644
---- a/src/observer/storage/common/condition_filter.h
-+++ b/src/observer/storage/common/condition_filter.h
-@@ -66,6 +66,8 @@ public:
-     return comp_op_;
-   }
- 
-+  AttrType attr_type() const { return attr_type_; }
-+
- private:
-   ConDesc left_;
-   ConDesc right_;
-diff --git a/src/observer/storage/common/table.cpp b/src/observer/storage/common/table.cpp
-index 7ff43ca..f53be21 100644
---- a/src/observer/storage/common/table.cpp
-+++ b/src/observer/storage/common/table.cpp
-@@ -326,7 +326,14 @@ RC Table::make_record(int value_num, const Value *values, char *&record_out)
-   for (int i = 0; i < value_num; i++) {
-     const FieldMeta *field = table_meta_.field(i + normal_field_start_index);
-     const Value &value = values[i];
--    memcpy(record + field->offset(), value.data, field->len());
-+    size_t copy_len = field->len();
-+    if (field->type() == CHARS) {
-+      const size_t data_len = strlen((const char *)value.data);
-+      if (copy_len > data_len) {
-+        copy_len = data_len + 1;
-+      }
-+    }
-+    memcpy(record + field->offset(), value.data, copy_len);
-   }
- 
-   record_out = record;
-@@ -775,6 +782,8 @@ IndexScanner *Table::find_index_for_scan(const DefaultConditionFilter &filter)
- 
-   const char *left_key = nullptr;
-   const char *right_key = nullptr;
-+  int left_len = 4;
-+  int right_len = 4;
-   bool left_inclusive = false;
-   bool right_inclusive = false;
-   switch (filter.comp_op()) {
-@@ -809,7 +818,12 @@ IndexScanner *Table::find_index_for_scan(const DefaultConditionFilter &filter)
-     return nullptr;
-   }
-   }
--  return index->create_scanner(left_key, left_inclusive, right_key, right_inclusive);
-+
-+  if (filter.attr_type() == CHARS) {
-+    left_len = left_key != nullptr ? strlen(left_key) : 0;
-+    right_len = right_key != nullptr ? strlen(right_key) : 0;
-+  }
-+  return index->create_scanner(left_key, left_len, left_inclusive, right_key, right_len, right_inclusive);
- }
- 
- IndexScanner *Table::find_index_for_scan(const ConditionFilter *filter)
-diff --git a/src/observer/storage/common/table.h b/src/observer/storage/common/table.h
-index a185535..7075537 100644
---- a/src/observer/storage/common/table.h
-+++ b/src/observer/storage/common/table.h
-@@ -29,6 +29,7 @@ class IndexScanner;
- class RecordDeleter;
- class Trx;
- 
-+// TODO remove the routines with condition
- class Table {
- public:
-   Table() = default;
-diff --git a/src/observer/storage/default/disk_buffer_pool.cpp b/src/observer/storage/default/disk_buffer_pool.cpp
-index e3953ae..18a2450 100644
---- a/src/observer/storage/default/disk_buffer_pool.cpp
-+++ b/src/observer/storage/default/disk_buffer_pool.cpp
-@@ -295,6 +295,8 @@ RC DiskBufferPool::allocate_page(Frame **frame)
- 
- RC DiskBufferPool::unpin_page(Frame *frame)
- {
-+  assert(frame->pin_count_ >= 1);
-+
-   if (--frame->pin_count_ == 0) {
-     PageNum page_num = frame->page_num();
-     auto pages_it = disposed_pages.find(page_num);
-diff --git a/src/observer/storage/index/bplus_tree.cpp b/src/observer/storage/index/bplus_tree.cpp
-index 50e49f1..0e7a62d 100644
---- a/src/observer/storage/index/bplus_tree.cpp
-+++ b/src/observer/storage/index/bplus_tree.cpp
-@@ -1443,10 +1443,10 @@ RC BplusTreeHandler::insert_entry(const char *user_key, const RID *rid)
-   return RC::SUCCESS;
- }
- 
--RC BplusTreeHandler::get_entry(const char *user_key, std::list<RID> &rids)
-+RC BplusTreeHandler::get_entry(const char *user_key, int key_len, std::list<RID> &rids)
- {
-   BplusTreeScanner scanner(*this);
--  RC rc = scanner.open(user_key, true/*left_inclusive*/, user_key, true/*right_inclusive*/);
-+  RC rc = scanner.open(user_key, key_len, true/*left_inclusive*/, user_key, key_len, true/*right_inclusive*/);
-   if (rc != RC::SUCCESS) {
-     LOG_WARN("failed to open scanner. rc=%d:%s", rc, strrc(rc));
-     return rc;
-@@ -1721,8 +1721,8 @@ BplusTreeScanner::~BplusTreeScanner()
-   close();
- }
- 
--RC BplusTreeScanner::open(const char *left_user_key, bool left_inclusive,
--                          const char *right_user_key, bool right_inclusive)
-+RC BplusTreeScanner::open(const char *left_user_key, int left_len, bool left_inclusive,
-+                          const char *right_user_key, int right_len, bool right_inclusive)
- {
-   RC rc = RC::SUCCESS;
-   if (inited_) {
-@@ -1753,10 +1753,30 @@ RC BplusTreeScanner::open(const char *left_user_key, bool left_inclusive,
-     iter_index_ = 0;
-   } else {
-     char *left_key = nullptr;
--    if (left_inclusive) { 
--      left_key = tree_handler_.make_key(left_user_key, *RID::min());
-+
-+    char *fixed_left_key = const_cast<char *>(left_user_key);
-+    if (tree_handler_.file_header_.attr_type == CHARS) {
-+      bool should_inclusive_after_fix = false;
-+      rc = fix_user_key(left_user_key, left_len, true/*greater*/, &fixed_left_key, &should_inclusive_after_fix);
-+      if (rc != RC::SUCCESS) {
-+	LOG_WARN("failed to fix left user key. rc=%s", strrc(rc));
-+	return rc;
-+      }
-+
-+      if (should_inclusive_after_fix) {
-+	left_inclusive = true;
-+      }
-+    }
-+
-+    if (left_inclusive) {
-+      left_key = tree_handler_.make_key(fixed_left_key, *RID::min());
-     } else {
--      left_key = tree_handler_.make_key(left_user_key, *RID::max());
-+      left_key = tree_handler_.make_key(fixed_left_key, *RID::max());
-+    }
-+
-+    if (fixed_left_key != left_user_key) {
-+      delete[] fixed_left_key;
-+      fixed_left_key = nullptr;
-     }
-     rc = tree_handler_.find_leaf(left_key, left_frame_);
- 
-@@ -1800,10 +1820,28 @@ RC BplusTreeScanner::open(const char *left_user_key, bool left_inclusive,
-   } else {
- 
-     char *right_key = nullptr;
-+    char *fixed_right_key = const_cast<char *>(right_user_key);
-+    bool should_include_after_fix = false;
-+    if (tree_handler_.file_header_.attr_type == CHARS) {
-+      rc = fix_user_key(right_user_key, right_len, false/*want_greater*/, &fixed_right_key, &should_include_after_fix);
-+      if (rc != RC::SUCCESS) {
-+	LOG_WARN("failed to fix right user key. rc=%s", strrc(rc));
-+	return rc;
-+      }
-+
-+      if (should_include_after_fix) {
-+	right_inclusive = true;
-+      }
-+    }
-     if (right_inclusive) {
--      right_key = tree_handler_.make_key(right_user_key, *RID::max());
-+      right_key = tree_handler_.make_key(fixed_right_key, *RID::max());
-     } else {
--      right_key = tree_handler_.make_key(right_user_key, *RID::min());
-+      right_key = tree_handler_.make_key(fixed_right_key, *RID::min());
-+    }
-+
-+    if (fixed_right_key != right_user_key) {
-+      delete[] fixed_right_key;
-+      fixed_right_key = nullptr;
-     }
- 
-     rc = tree_handler_.find_leaf(right_key, right_frame_);
-@@ -1883,11 +1921,13 @@ RC BplusTreeScanner::next_entry(RID *rid)
-     PageNum page_num = node.next_page();
-     tree_handler_.disk_buffer_pool_->unpin_page(left_frame_);
-     if (page_num == BP_INVALID_PAGE_NUM) {
-+      left_frame_ = nullptr;
-       LOG_WARN("got invalid next page. page num=%d", page_num);
-       rc = RC::INTERNAL;
-     } else {
-       rc = tree_handler_.disk_buffer_pool_->get_this_page(page_num, &left_frame_);
-       if (rc != RC::SUCCESS) {
-+	left_frame_ = nullptr;
-         LOG_WARN("failed to fetch next page. page num=%d, rc=%d:%s", page_num, rc, strrc(rc));
-         return rc;
-       }
-@@ -1906,12 +1946,64 @@ RC BplusTreeScanner::close()
- {
-   if (left_frame_ != nullptr) {
-     tree_handler_.disk_buffer_pool_->unpin_page(left_frame_);
-+    left_frame_ = nullptr;
-   }
-   if (right_frame_ != nullptr) {
-     tree_handler_.disk_buffer_pool_->unpin_page(right_frame_);
-+    right_frame_ = nullptr;
-   }
-   end_index_ = -1;
-   inited_ = false;
-   LOG_INFO("bplus tree scanner closed");
-   return RC::SUCCESS;
- }
-+
-+RC BplusTreeScanner::fix_user_key(const char *user_key, int key_len, bool want_greater,
-+			      char **fixed_key, bool *should_inclusive)
-+{
-+  if (nullptr == fixed_key || nullptr == should_inclusive) {
-+    return RC::INVALID_ARGUMENT;
-+  }
-+
-+  // 这里很粗暴，变长字段才需要做调整，其它默认都不需要做调整
-+  assert(tree_handler_.file_header_.attr_type == CHARS);
-+  assert(strlen(user_key) >= static_cast<size_t>(key_len));
-+  
-+  *should_inclusive = false;
-+  
-+  int32_t attr_length = tree_handler_.file_header_.attr_length;
-+  char *key_buf = new (std::nothrow)char [attr_length];
-+  if (nullptr == key_buf) {
-+    return RC::NOMEM;
-+  }
-+
-+  if (key_len <= attr_length) {
-+    memcpy(key_buf, user_key, key_len);
-+    memset(key_buf + key_len, 0, attr_length - key_len);
-+
-+    *fixed_key = key_buf;
-+    return RC::SUCCESS;
-+  }
-+
-+  // key_len > attr_length
-+  memcpy(key_buf, user_key, attr_length);
-+
-+  char c = user_key[attr_length];
-+  if (c == 0) {
-+    *fixed_key = key_buf;
-+    return RC::SUCCESS;
-+  }
-+
-+  // 扫描 >=/> user_key 的数据
-+  // 示例：>=/> ABCD1 的数据，attr_length=4,
-+  //      等价于扫描 >= ABCE 的数据
-+  // 如果是扫描 <=/< user_key的数据
-+  // 示例：<=/< ABCD1  <==> <= ABCD  (attr_length=4)
-+  *should_inclusive = true;
-+  if (want_greater) {
-+    key_buf[attr_length - 1]++;
-+  }
-+  
-+  *fixed_key = key_buf;
-+  return RC::SUCCESS;
-+}
-diff --git a/src/observer/storage/index/bplus_tree.h b/src/observer/storage/index/bplus_tree.h
-index 91d9d48..7a09b1b 100644
---- a/src/observer/storage/index/bplus_tree.h
-+++ b/src/observer/storage/index/bplus_tree.h
-@@ -118,7 +118,14 @@ public:
-       return std::to_string(*(float*)v);
-     }
-     case CHARS: {
--      return std::string(v, attr_length_);
-+      std::string str;
-+      for (int i = 0; i < attr_length_; i++) {
-+	if (v[i] == 0) {
-+	  break;
-+	}
-+	str.push_back(v[i]);
-+      }
-+      return str;
-     }
-     default:{
-       LOG_ERROR("unknown attr type. %d", attr_type_);
-@@ -400,12 +407,14 @@ public:
-    * 此函数向IndexHandle对应的索引中插入一个索引项。
-    * 参数user_key指向要插入的属性值，参数rid标识该索引项对应的元组，
-    * 即向索引中插入一个值为（user_key，rid）的键值对
-+   * @note 这里假设user_key的内存大小与attr_length 一致
-    */
-   RC insert_entry(const char *user_key, const RID *rid);
- 
-   /**
-    * 从IndexHandle句柄对应的索引中删除一个值为（*pData，rid）的索引项
-    * @return RECORD_INVALID_KEY 指定值不存在
-+   * @note 这里假设user_key的内存大小与attr_length 一致
-    */
-   RC delete_entry(const char *user_key, const RID *rid);
- 
-@@ -413,9 +422,10 @@ public:
- 
-   /**
-    * 获取指定值的record
-+   * @param key_len user_key的长度
-    * @param rid  返回值，记录记录所在的页面号和slot
-    */
--  RC get_entry(const char *user_key, std::list<RID> &rids);
-+  RC get_entry(const char *user_key, int key_len, std::list<RID> &rids);
- 
-   RC sync();
- 
-@@ -493,18 +503,26 @@ public:
- 
-   /**
-    * 扫描指定范围的数据
--   * @param left_key 扫描范围的左边界，如果是null，则没有左边界
-+   * @param left_user_key 扫描范围的左边界，如果是null，则没有左边界
-+   * @param left_len left_user_key 的内存大小(只有在变长字段中才会关注)
-    * @param left_inclusive 左边界的值是否包含在内
--   * @param right_key 扫描范围的右边界。如果是null，则没有右边界
-+   * @param right_user_key 扫描范围的右边界。如果是null，则没有右边界
-+   * @param right_len right_user_key 的内存大小(只有在变长字段中才会关注)
-    * @param right_inclusive 右边界的值是否包含在内
-    */
--  RC open(const char *left_user_key, bool left_inclusive,
--	  const char *right_user_key, bool right_inclusive);
-+  RC open(const char *left_user_key, int left_len, bool left_inclusive,
-+	  const char *right_user_key, int right_len, bool right_inclusive);
- 
-   RC next_entry(RID *rid);
- 
-   RC close();
- 
-+private:
-+  /**
-+   * 如果key的类型是CHARS, 扩展或缩减user_key的大小刚好是schema中定义的大小
-+   */
-+  RC fix_user_key(const char *user_key, int key_len, bool want_greater,
-+		  char **fixed_key, bool *should_inclusive);
- private:
-   bool inited_ = false;
-   BplusTreeHandler &tree_handler_;
-diff --git a/src/observer/storage/index/bplus_tree_index.cpp b/src/observer/storage/index/bplus_tree_index.cpp
-index ea69bcc..cbaef5c 100644
---- a/src/observer/storage/index/bplus_tree_index.cpp
-+++ b/src/observer/storage/index/bplus_tree_index.cpp
-@@ -98,11 +98,11 @@ RC BplusTreeIndex::delete_entry(const char *record, const RID *rid)
-   return index_handler_.delete_entry(record + field_meta_.offset(), rid);
- }
- 
--IndexScanner *BplusTreeIndex::create_scanner(const char *left_key, bool left_inclusive,
--					     const char *right_key, bool right_inclusive)
-+IndexScanner *BplusTreeIndex::create_scanner(const char *left_key, int left_len, bool left_inclusive,
-+					     const char *right_key, int right_len, bool right_inclusive)
- {
-   BplusTreeIndexScanner *index_scanner = new BplusTreeIndexScanner(index_handler_);
--  RC rc = index_scanner->open(left_key, left_inclusive, right_key, right_inclusive);
-+  RC rc = index_scanner->open(left_key, left_len, left_inclusive, right_key, right_len, right_inclusive);
-   if (rc != RC::SUCCESS) {
-     LOG_WARN("failed to open index scanner. rc=%d:%s", rc, strrc(rc));
-     delete index_scanner;
-@@ -125,9 +125,10 @@ BplusTreeIndexScanner::~BplusTreeIndexScanner() noexcept
-   tree_scanner_.close();
- }
- 
--RC BplusTreeIndexScanner::open(const char *left_key, bool left_inclusive, const char *right_key, bool right_inclusive)
-+RC BplusTreeIndexScanner::open(const char *left_key, int left_len, bool left_inclusive,
-+                               const char *right_key, int right_len, bool right_inclusive)
- {
--  return tree_scanner_.open(left_key, left_inclusive, right_key, right_inclusive);
-+  return tree_scanner_.open(left_key, left_len, left_inclusive, right_key, right_len, right_inclusive);
- }
- 
- RC BplusTreeIndexScanner::next_entry(RID *rid)
-diff --git a/src/observer/storage/index/bplus_tree_index.h b/src/observer/storage/index/bplus_tree_index.h
-index 1c3ff92..c2e66f1 100644
---- a/src/observer/storage/index/bplus_tree_index.h
-+++ b/src/observer/storage/index/bplus_tree_index.h
-@@ -33,8 +33,8 @@ public:
-   /**
-    * 扫描指定范围的数据
-    */
--  IndexScanner *create_scanner(const char *left_key, bool left_inclusive,
--			       const char *right_key, bool right_inclusive) override;
-+  IndexScanner *create_scanner(const char *left_key, int left_len, bool left_inclusive,
-+			       const char *right_key, int right_len, bool right_inclusive) override;
- 
-   RC sync() override;
- 
-@@ -51,7 +51,8 @@ public:
-   RC next_entry(RID *rid) override;
-   RC destroy() override;
- 
--  RC open(const char *left_key, bool left_inclusive, const char *right_key, bool right_inclusive);
-+  RC open(const char *left_key, int left_len, bool left_inclusive,
-+          const char *right_key, int right_len, bool right_inclusive);
- private:
-   BplusTreeScanner tree_scanner_;
- };
-diff --git a/src/observer/storage/index/index.h b/src/observer/storage/index/index.h
-index d66a093..4f04fb4 100644
---- a/src/observer/storage/index/index.h
-+++ b/src/observer/storage/index/index.h
-@@ -46,8 +46,8 @@ public:
-   virtual RC insert_entry(const char *record, const RID *rid) = 0;
-   virtual RC delete_entry(const char *record, const RID *rid) = 0;
- 
--  virtual IndexScanner *create_scanner(const char *left_key, bool left_inclusive,
--				       const char *right_key, bool right_inclusive) = 0;
-+  virtual IndexScanner *create_scanner(const char *left_key, int left_len, bool left_inclusive,
-+				       const char *right_key, int right_len, bool right_inclusive) = 0;
- 
-   virtual RC sync() = 0;
- 
-diff --git a/src/observer/util/comparator.cpp b/src/observer/util/comparator.cpp
-index f7e6a8e..1c8615f 100644
---- a/src/observer/util/comparator.cpp
-+++ b/src/observer/util/comparator.cpp
-@@ -13,6 +13,7 @@ See the Mulan PSL v2 for more details. */
- //
- 
- #include <string.h>
-+#include <algorithm>
- 
- const double epsilon = 1E-6;
- 
-@@ -37,9 +38,22 @@ int compare_float(void *arg1, void *arg2)
-   return 0;
- }
- 
--int compare_string(void *arg1, void *arg2, int maxlen)
-+int compare_string(void *arg1, int arg1_max_length, void *arg2, int arg2_max_length)
- {
-   const char *s1 = (const char *)arg1;
-   const char *s2 = (const char *)arg2;
--  return strncmp(s1, s2, maxlen);
-+  int maxlen = std::min(arg1_max_length, arg2_max_length);
-+  int result =  strncmp(s1, s2, maxlen);
-+  if (0 != result) {
-+    return result;
-+  }
-+
-+  if (arg1_max_length > maxlen) {
-+    return s1[maxlen] - 0;
-+  }
-+
-+  if (arg2_max_length > maxlen) {
-+    return 0 - s2[maxlen];
-+  }
-+  return 0;
- }
-diff --git a/src/observer/util/comparator.h b/src/observer/util/comparator.h
-index c80e9f2..18ab99f 100644
---- a/src/observer/util/comparator.h
-+++ b/src/observer/util/comparator.h
-@@ -16,4 +16,4 @@ See the Mulan PSL v2 for more details. */
- 
- int compare_int(void *arg1, void *arg2);
- int compare_float(void *arg1, void *arg2);
--int compare_string(void *arg1, void *arg2, int max_length);
-+int compare_string(void *arg1, int arg1_max_length, void *arg2, int arg2_max_length);
-diff --git a/unitest/bplus_tree_test.cpp b/unitest/bplus_tree_test.cpp
-index 5fa48fd..dabfe08 100644
---- a/unitest/bplus_tree_test.cpp
-+++ b/unitest/bplus_tree_test.cpp
-@@ -31,6 +31,7 @@ using namespace common;
- #define INSERT_NUM (TIMES * ORDER * ORDER * ORDER * ORDER)
- #define POOL_NUM 2
- 
-+BufferPoolManager bpm;
- BplusTreeHandler *handler = nullptr;
- const char *index_name = "test.btree";
- int insert_num = INSERT_NUM;
-@@ -38,6 +39,12 @@ const int page_size = 1024;
- RID rid, check_rid;
- int k = 0;
- 
-+void init_bpm()
-+{
-+  if (&BufferPoolManager::instance() == nullptr) {
-+    BufferPoolManager::set_instance(&bpm);
-+  }
-+}
- void test_insert()
- {
-   RC rc = RC::SUCCESS;
-@@ -148,7 +155,7 @@ void test_get()
-     }
- 
-     rids.clear();
--    RC rc = handler->get_entry((const char *)&i, rids);
-+    RC rc = handler->get_entry((const char *)&i, 4, rids);
- 
-     ASSERT_EQ(RC::SUCCESS, rc);
-     ASSERT_EQ(1, rids.size());
-@@ -221,7 +228,7 @@ void test_delete()
-       LOG_INFO("Begin to get entry of index, i=%d, rid: %s", i, rid.to_string().c_str());
-     }
-     rids.clear();
--    rc = handler->get_entry((const char *)&i, rids);
-+    rc = handler->get_entry((const char *)&i, 4, rids);
-     ASSERT_EQ(RC::SUCCESS, rc);
-     int t = i % TIMES;
-     if (t == 0 || t == 1) {
-@@ -458,6 +465,50 @@ TEST(test_bplus_tree, test_internal_index_node_handle)
-     ASSERT_EQ(i, index);
-   }
- }
-+
-+TEST(test_bplus_tree, test_chars)
-+{
-+  LoggerFactory::init_default("test_chars.log");
-+
-+  const char *index_name = "chars.btree";
-+  ::remove(index_name);
-+  handler = new BplusTreeHandler();
-+  handler->create(index_name, CHARS, 8, ORDER, ORDER);
-+
-+  char keys[][9] = {
-+    "abcdefg",
-+    "12345678",
-+    "12345678",
-+    "abcdefg",
-+    "abcdefga"
-+  };
-+
-+  RID rid;
-+  RC rc = RC::SUCCESS;
-+  for (size_t i = 0; i < sizeof(keys)/sizeof(keys[0]); i++) {
-+    rid.page_num = 0;
-+    rid.slot_num = i;
-+    rc = handler->insert_entry(keys[i], &rid);
-+    ASSERT_EQ(RC::SUCCESS, rc);
-+  }
-+
-+  LOG_INFO("begin to print bplus tree of chars");
-+  handler->print_tree();
-+  LOG_INFO("end to print bplus tree of chars");
-+
-+  BplusTreeScanner scanner(*handler);
-+  const char *key = "abcdefg";
-+  rc = scanner.open(key, strlen(key), true, key, strlen(key), true);
-+  ASSERT_EQ(rc, RC::SUCCESS);
-+
-+  int count = 0;
-+  while (RC::SUCCESS == (rc = scanner.next_entry(&rid))) {
-+    count++;
-+  }
-+  scanner.close();
-+  ASSERT_EQ(2, count);
-+}
-+
- TEST(test_bplus_tree, test_scanner)
- {
-   LoggerFactory::init_default("test.log");
-@@ -484,7 +535,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   int begin = -100;
-   int end = -20;
--  rc = scanner.open((const char *)&begin, false, (const char *)&end, false);
-+  rc = scanner.open((const char *)&begin, 4, false, (const char *)&end, 4, false);
-   ASSERT_EQ(RC::SUCCESS, rc);
- 
-   rc = scanner.next_entry(&rid);
-@@ -494,7 +545,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = -100;
-   end = 1;
--  rc = scanner.open((const char *)&begin, false, (const char *)&end, false);
-+  rc = scanner.open((const char *)&begin, 4, false, (const char *)&end, 4, false);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   rc = scanner.next_entry(&rid);
-   ASSERT_EQ(RC::RECORD_EOF, rc);
-@@ -503,7 +554,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = -100;
-   end = 1;
--  rc = scanner.open((const char *)&begin, false, (const char *)&end, true/*inclusive*/);
-+  rc = scanner.open((const char *)&begin, 4, false, (const char *)&end, 4, true/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   rc = scanner.next_entry(&rid);
-   ASSERT_EQ(RC::SUCCESS, rc);
-@@ -514,7 +565,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = 1;
-   end = 3;
--  rc = scanner.open((const char *)&begin, false, (const char *)&end, false/*inclusive*/);
-+  rc = scanner.open((const char *)&begin, 4, false, (const char *)&end, 4, false/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   rc = scanner.next_entry(&rid);
-   ASSERT_EQ(RC::RECORD_EOF, rc);
-@@ -523,7 +574,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = 1;
-   end = 3;
--  rc = scanner.open((const char *)&begin, true, (const char *)&end, true/*inclusive*/);
-+  rc = scanner.open((const char *)&begin, 4, true, (const char *)&end, 4, true/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   while ((rc = scanner.next_entry(&rid)) == RC::SUCCESS) {
-     count++;
-@@ -535,7 +586,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = 0;
-   end = 3;
--  rc = scanner.open((const char *)&begin, true, (const char *)&end, true/*inclusive*/);
-+  rc = scanner.open((const char *)&begin, 4, true, (const char *)&end, 4, true/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   count = 0;
-   while ((rc = scanner.next_entry(&rid)) == RC::SUCCESS) {
-@@ -548,7 +599,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = 11;
-   end = 21;
--  rc = scanner.open((const char *)&begin, true, (const char *)&end, true/*inclusive*/);
-+  rc = scanner.open((const char *)&begin, 4, true, (const char *)&end, 4, true/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   count = 0;
-   while ((rc = scanner.next_entry(&rid)) == RC::SUCCESS) {
-@@ -561,7 +612,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = 11;
-   end = 91;
--  rc = scanner.open((const char *)&begin, true, (const char *)&end, true/*inclusive*/);
-+  rc = scanner.open((const char *)&begin, 4, true, (const char *)&end, 4, true/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   count = 0;
-   while ((rc = scanner.next_entry(&rid)) == RC::SUCCESS) {
-@@ -574,7 +625,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = 191;
-   end = 199;
--  rc = scanner.open((const char *)&begin, true, (const char *)&end, true/*inclusive*/);
-+  rc = scanner.open((const char *)&begin, 4, true, (const char *)&end, 4, true/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   count = 0;
-   while ((rc = scanner.next_entry(&rid)) == RC::SUCCESS) {
-@@ -587,7 +638,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = 191;
-   end = 201;
--  rc = scanner.open((const char *)&begin, true, (const char *)&end, true/*inclusive*/);
-+  rc = scanner.open((const char *)&begin, 4, true, (const char *)&end, 4, true/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   count = 0;
-   while ((rc = scanner.next_entry(&rid)) == RC::SUCCESS) {
-@@ -600,7 +651,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = 200;
-   end = 301;
--  rc = scanner.open((const char *)&begin, true, (const char *)&end, true/*inclusive*/);
-+  rc = scanner.open((const char *)&begin, 4, true, (const char *)&end, 4, true/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   rc = scanner.next_entry(&rid);
-   ASSERT_EQ(RC::RECORD_EOF, rc);
-@@ -609,14 +660,14 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = 300;
-   end = 201;
--  rc = scanner.open((const char *)&begin, true, (const char *)&end, true/*inclusive*/);
-+  rc = scanner.open((const char *)&begin, 4, true, (const char *)&end, 4, true/*inclusive*/);
-   ASSERT_EQ(RC::INVALID_ARGUMENT, rc);
- 
-   scanner.close();
- 
-   begin = 300;
-   end = 201;
--  rc = scanner.open(nullptr, true, (const char *)&end, true/*inclusive*/);
-+  rc = scanner.open(nullptr, 4, true, (const char *)&end, 4, true/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   count = 0;
-   while ((rc = scanner.next_entry(&rid)) == RC::SUCCESS) {
-@@ -629,7 +680,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = 300;
-   end = 10;
--  rc = scanner.open(nullptr, true, (const char *)&end, true/*inclusive*/);
-+  rc = scanner.open(nullptr, 4, true, (const char *)&end, 4, true/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   count = 0;
-   while ((rc = scanner.next_entry(&rid)) == RC::SUCCESS) {
-@@ -642,7 +693,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = 190;
-   end = 10;
--  rc = scanner.open((const char *)&begin, true, nullptr, true/*inclusive*/);
-+  rc = scanner.open((const char *)&begin, 4, true, nullptr, 4, true/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   count = 0;
-   while ((rc = scanner.next_entry(&rid)) == RC::SUCCESS) {
-@@ -655,7 +706,7 @@ TEST(test_bplus_tree, test_scanner)
- 
-   begin = 190;
-   end = 10;
--  rc = scanner.open(nullptr, true, nullptr, true/*inclusive*/);
-+  rc = scanner.open(nullptr, 0, true, nullptr, 0, true/*inclusive*/);
-   ASSERT_EQ(RC::SUCCESS, rc);
-   count = 0;
-   while ((rc = scanner.next_entry(&rid)) == RC::SUCCESS) {
-@@ -695,6 +746,7 @@ int main(int argc, char **argv)
-   // 调用RUN_ALL_TESTS()运行所有测试用例
-   // main函数返回RUN_ALL_TESTS()的运行结果
- 
-+  init_bpm();
-   int rc = RUN_ALL_TESTS();
- 
-   return rc;