diff --git a/db/db_impl.cc b/db/db_impl.cc
index 9dc5220..4c0f2e5 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -1276,6 +1276,7 @@ Status DBImpl::Put(const WriteOptions& opt, const Slice& key, const Slice& val)
   // TODO: allocate slot_num in slotpage and put value in vlog
 
   size_t slot_num = slot_page_->alloc_slot();
+//  std::string slot_num_str((char *)&slot_num, sizeof(size_t));
   struct slot_content sc;
   vlog_set_->put_value(&sc.vlog_num, &sc.value_offset, val);
   slot_page_->set_slot(slot_num, &sc);
diff --git a/db/vlog.h b/db/vlog.h
index 20c1ceb..b48d72b 100644
--- a/db/vlog.h
+++ b/db/vlog.h
@@ -19,7 +19,7 @@
 
 // config file: | vlog_nums_(size_t) | vlog_1_name | vlog_2_name | ... |
 // vlog: | curr_size(size_t) | value_nums(size_t) | value1 | value2 | ... |
-// value: | value_size(uint16_t) ｜ field_nums(uint16_t) | slot_num(size_t) | value |
+// value: | value_size(uint16_t) | slot_num(size_t) | field_nums(uint16_t) ｜ value |
 
 #define vlog_num_size     sizeof(size_t)
 #define vlog_name_size    256
diff --git a/db/vlog_set.cpp b/db/vlog_set.cpp
index e598c03..84793bf 100644
--- a/db/vlog_set.cpp
+++ b/db/vlog_set.cpp
@@ -290,7 +290,7 @@ struct vlog_handler * VlogSet::get_vlog_handler(size_t vlog_num) {
   return vlog_handler_map_[get_vlog_name(vlog_num)];
 }
 
-// value: | field_nums(uint16_t) | slot_num(size_t) | value |
+// value: | value_size(uint16_t) | slot_num(size_t) | field_nums(uint16_t) ｜ value |
 void VlogSet::read_vlog_value(uint32_t vlog_num, uint32_t value_offset, std::string *value) {
   auto vlog_name = get_vlog_name(vlog_num);
   auto handler = std::fstream(vlog_name, std::ios::in | std::ios::out);
@@ -302,8 +302,9 @@ void VlogSet::read_vlog_value(uint32_t vlog_num, uint32_t value_offset, std::str
   uint16_t value_size;
   memcpy(&value_size, value_buff, sizeof(uint16_t));
   value_size &= VALUE_SIZE_MASK;
-  *value = std::string(value_buff);
-//  value->assign(&value_buff[sizeof(uint16_t)], value_size);
+//  *value = std::string(value_buff);
+  assert(value_size <= VALUE_BUFF_SIZE);
+  value->assign(&value_buff[sizeof(uint16_t)], value_size);
   handler.close();
 }