diff --git a/deps/oblib/src/common/object/ob_obj_funcs.h b/deps/oblib/src/common/object/ob_obj_funcs.h
index 9d51601313..8afa499cf2 100644
--- a/deps/oblib/src/common/object/ob_obj_funcs.h
+++ b/deps/oblib/src/common/object/ob_obj_funcs.h
@@ -1490,35 +1490,7 @@ DEF_ENUMSET_INNER_FUNCS(ObSetInnerType, set_inner, ObString);
   }
 
 #define DEF_TEXT_SERIALIZE_FUNCS(OBJTYPE, TYPE, VTYPE)                       \
-  template <>                                                           \
-      inline int obj_val_serialize<OBJTYPE>(const ObObj &obj, char* buf, \
-                                            const int64_t buf_len, int64_t& pos) \
-  {                                                                     \
-   int ret = OB_SUCCESS;                                                \
-   OB_UNIS_ENCODE(obj.get_##TYPE());                                    \
-   return ret;                                                          \
-   }                                                                    \
-                                                                        \
-  template <>                                                           \
-  inline int obj_val_deserialize<OBJTYPE>(ObObj &obj, const char* buf,  \
-                                          const int64_t data_len, int64_t& pos) \
-  {                                                                     \
-   int ret = OB_SUCCESS;                                                \
-   VTYPE v = VTYPE();                                                   \
-   OB_UNIS_DECODE(v);                                                   \
-   if (OB_SUCC(ret)) {                                                  \
-     obj.set_##TYPE(OBJTYPE, v);                                        \
-   }                                                                    \
-   return ret;                                                          \
-  }                                                                    \
-                                                                        \
-  template <>                                                           \
-  inline int64_t obj_val_get_serialize_size<OBJTYPE>(const ObObj &obj)         \
-  {                                                                     \
-   int64_t len = 0;                                                     \
-   OB_UNIS_ADD_LEN(obj.get_##TYPE());                                   \
-   return len;                                                          \
-   }
+  DEF_SERIALIZE_FUNCS(OBJTYPE, TYPE, VTYPE)
 
 // ToDo: @gehao
 // 1. SERIALIZE/DESERIALIZE will drop has_lob_header flag. However, only table api use these functions,
@@ -1950,7 +1922,7 @@ inline int obj_print_json<ObJsonType>(const ObObj &obj, char *buf, int64_t buf_l
     ret = serialization::decode_otimestamp_tz_type(buf, buf_len, pos, \
                                                    *((int64_t *)&ot_data.time_us_), \
                                                    *((uint32_t *)&ot_data.time_ctx_.desc_)); \
-    obj.set_otimestamp_value(OBJTYPE, ot_data);\
+    obj.set_obj_value(ot_data);\
     return ret;\
   }                                                                     \
                                                                         \
@@ -2036,7 +2008,7 @@ inline int obj_print_json<ObJsonType>(const ObObj &obj, char *buf, int64_t buf_l
     ret = serialization::decode_otimestamp_type(buf, buf_len, pos, \
                                                 *((int64_t *)&ot_data.time_us_), \
                                                 *((uint16_t *)&ot_data.time_ctx_.time_desc_)); \
-    obj.set_otimestamp_value(OBJTYPE, ot_data);\
+    obj.set_obj_value(ot_data);\
     return ret;\
   }                                                                     \
                                                                         \
@@ -2395,7 +2367,7 @@ template <>
   int64_t val = 0;
   OB_UNIS_DECODE(val);
   if (OB_SUCC(ret)) {
-    obj.set_unknown(val);
+    obj.set_obj_value(val);
   }
   return ret;
 }
diff --git a/deps/oblib/src/common/object/ob_object.h b/deps/oblib/src/common/object/ob_object.h
index ed7a0fcf94..3ed7c62317 100644
--- a/deps/oblib/src/common/object/ob_object.h
+++ b/deps/oblib/src/common/object/ob_object.h
@@ -3790,6 +3790,7 @@ DEFINE_SET_COMMON_OBJ_VALUE(float, float);
 DEFINE_SET_COMMON_OBJ_VALUE(double, double);
 DEFINE_SET_COMMON_OBJ_VALUE(int64, int64_t);
 DEFINE_SET_COMMON_OBJ_VALUE(uint64, uint64_t);
+
 template<>
 inline void ObObj::set_obj_value<ObString>(const ObString &v)
 {
@@ -3818,6 +3819,13 @@ inline void ObObj::set_obj_value<ObURowIDData>(const ObURowIDData &urowid)
   val_len_ = static_cast<int32_t>(urowid.rowid_len_);
 }
 
+template<>
+inline void ObObj::set_obj_value<ObOTimestampData>(const ObOTimestampData &otimestamp)
+{
+  time_ctx_ = otimestamp.time_ctx_;
+  v_.datetime_ = otimestamp.time_us_;
+}
+
 struct ParamFlag
 {
   ParamFlag() : need_to_check_type_(true),
diff --git a/src/sql/engine/expr/ob_expr_rownum.cpp b/src/sql/engine/expr/ob_expr_rownum.cpp
index 6b41205c42..45989f0962 100644
--- a/src/sql/engine/expr/ob_expr_rownum.cpp
+++ b/src/sql/engine/expr/ob_expr_rownum.cpp
@@ -61,7 +61,10 @@ int ObExprRowNum::rownum_eval(const ObExpr &expr, ObEvalCtx &ctx, ObDatum &expr_
   int ret = OB_SUCCESS;
   uint64_t operator_id = expr.extra_;
   ObOperatorKit *kit = ctx.exec_ctx_.get_operator_kit(operator_id);
-  if (OB_ISNULL(kit) || OB_ISNULL(kit->op_)) {
+  if (OB_UNLIKELY(OB_INVALID_ID == operator_id)) {
+    ret = OB_ERR_CBY_PSEUDO_COLUMN_NOT_ALLOWED;
+    LOG_USER_ERROR(OB_NOT_SUPPORTED, "Usage of rownum is");
+  } else if (OB_ISNULL(kit) || OB_ISNULL(kit->op_)) {
     ret = OB_ERR_UNEXPECTED;
     LOG_WARN("operator is NULL", K(ret), K(operator_id), KP(kit));
   } else if (OB_UNLIKELY(PHY_COUNT != kit->op_->get_spec().type_)) {
diff --git a/src/sql/resolver/ob_resolver_utils.cpp b/src/sql/resolver/ob_resolver_utils.cpp
index 7a35f38232..878daa9ba0 100644
--- a/src/sql/resolver/ob_resolver_utils.cpp
+++ b/src/sql/resolver/ob_resolver_utils.cpp
@@ -4763,6 +4763,9 @@ int ObResolverUtils::resolve_default_expr_v2_column_expr(ObResolverParams &param
     LOG_USER_ERROR(OB_ERR_BAD_FIELD_ERROR, col_name.length(), col_name.ptr(), scope_name.length(), scope_name.ptr());
   } else if (OB_FAIL(expr->formalize(session_info))) {
     LOG_WARN("formalize expr failed", K(ret));
+  } else if (OB_UNLIKELY(expr->has_flag(CNT_ROWNUM))) {
+    ret = OB_ERR_CBY_PSEUDO_COLUMN_NOT_ALLOWED;
+    LOG_WARN("rownum in default value is not allowed", K(ret));
   } else {
     LOG_DEBUG("succ to resolve_default_expr_v2_column_expr",
               "is_const_expr", expr->is_const_raw_expr(),