diff --git a/CMakeLists.txt b/CMakeLists.txt
index 34df416..6c415e1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -33,6 +33,8 @@ OPTION(ENABLE_NOPIE "Enable no pie" OFF)
 OPTION(CONCURRENCY "Support concurrency operations" ON)
 OPTION(STATIC_STDLIB "Link std library static or dynamic, such as libgcc, libstdc++, libasan" OFF)
 
+SET(CONCURRENCY ON)
+
 # ==================
 # === Compiler =====
 # ==================
diff --git a/src/observer/storage/index/index.h b/src/observer/storage/index/index.h
index f02b426..47c1800 100644
--- a/src/observer/storage/index/index.h
+++ b/src/observer/storage/index/index.h
@@ -83,6 +83,9 @@ class Index
 protected:
   IndexMeta index_meta_;  ///< 索引的元数据
   FieldMeta field_meta_;  ///< 当前实现仅考虑一个字段的索引
+
+
+  bool is_unique_;  ///< 是否是唯一索引
 };
 
 /**