diff --git a/src/sql/engine/basic/ob_compact_row.h b/src/sql/engine/basic/ob_compact_row.h
index e8081b6db3..98cacc59f6 100644
--- a/src/sql/engine/basic/ob_compact_row.h
+++ b/src/sql/engine/basic/ob_compact_row.h
@@ -26,22 +26,13 @@ class ObIAllocator;
 namespace sql
 {
 struct RowHeader {
-  RowHeader() : row_size_(0), has_null_(false) {}
+  RowHeader() : row_size_(0) {}
 
-  TO_STRING_KV(K_(row_size), K_(offset_len), K_(has_null));
+  TO_STRING_KV(K_(row_size));
 
 public:
   static const int64_t OFFSET_LEN = 4;
   uint32_t row_size_;
-  union {
-    struct {
-      //TODO shengle support dynamic offset len, no use now, now only use int32_t
-      uint32_t offset_len_    : 3;
-      uint32_t has_null_      : 1;
-      uint32_t reserved_      : 28;
-    };
-    uint32_t flag_;
-  };
 };
 
 struct RowMeta {
@@ -190,7 +181,6 @@ struct ObCompactRow
 
   inline void set_null(const RowMeta &meta, const int64_t col_idx) {
     nulls()->set(col_idx);
-    header_.has_null_ = true;
     if (meta.fixed_expr_reordered()) {
       const int32_t idx = meta.project_idx(col_idx);
       if (idx < meta.fixed_cnt_) {