diff --git a/cpp/src/db/DBImpl.cpp b/cpp/src/db/DBImpl.cpp
index b92518d6961f3ba2abcfa7b53a3f354aff0b5923..7dc61679c3813a0b670d3b2b05faa37494ca86b4 100644
--- a/cpp/src/db/DBImpl.cpp
+++ b/cpp/src/db/DBImpl.cpp
@@ -133,6 +133,7 @@ Status DBImpl::merge_files(const std::string& group_id, const meta::DateT& date,
     } else {
         group_file.file_type = meta::GroupFileSchema::RAW;
     }
+    group_file.rows = index_size;
     updated.push_back(group_file);
     status = _pMeta->update_files(updated);
 
@@ -188,6 +189,7 @@ Status DBImpl::build_index(const meta::GroupFileSchema& file) {
     /* std::cout << "raw size=" << from_index->ntotal << "   index size=" << index->ntotal << std::endl; */
     write_index(index, group_file.location.c_str());
     group_file.file_type = meta::GroupFileSchema::INDEX;
+    group_file.rows = file.dimension * index->ntotal;
 
     auto to_remove = file;
     to_remove.file_type = meta::GroupFileSchema::TO_DELETE;
diff --git a/cpp/src/db/DBMetaImpl.cpp b/cpp/src/db/DBMetaImpl.cpp
index 126a64c8af0a7643cf828ee4414a9b7aeddb74d3..3b0f520673edfde1e8b750fe8fa6549294f93880 100644
--- a/cpp/src/db/DBMetaImpl.cpp
+++ b/cpp/src/db/DBMetaImpl.cpp
@@ -165,6 +165,7 @@ Status DBMetaImpl::add_group_file(GroupFileSchema& group_file) {
     group_file.file_type = GroupFileSchema::NEW;
     group_file.file_id = ss.str();
     group_file.dimension = group_info.dimension;
+    group_file.rows = 0;
     GetGroupFilePath(group_file);
 
     {