message: print some info while loading database
diff: @@ -740,11 +740,15 @@ Database::load(bool loadCSR)
  return false;
  }
  + else{
  + cout<<"load kvstore successfully!"<<endl;
  + }
  this->stringindex->SetTrie(this->kvstore->getTrie());
  //NOTICE: we should also run some heavy work in the main thread
  this->stringindex->load();
  + cout<<"load stringindex successfully!"<<endl;
  this->readIDinfo();
  #ifdef THREAD_ON
  @@ -786,7 +790,7 @@ Database::load(bool loadCSR)
  #endif
  //load cache of sub2values and obj2values
  this->load_cache();
  -
  + cout<<"load cache successfully!"<<endl;
  //warm up always as finishing build(), to utilize the system buffer
  //this->warmUp();
  //DEBUG:the warmUp() calls query(), which will also output results, this is not we want
  