diff --git a/src/sql/engine/expr/ob_datum_cast.cpp b/src/sql/engine/expr/ob_datum_cast.cpp
index 118e6d1e3f..f06c33eaae 100644
--- a/src/sql/engine/expr/ob_datum_cast.cpp
+++ b/src/sql/engine/expr/ob_datum_cast.cpp
@@ -7681,7 +7681,7 @@ int cast_to_udt_not_support(const sql::ObExpr &expr, sql::ObEvalCtx &ctx, sql::O
     // other udts
     // ORA-00932: inconsistent datatypes: expected PLSQL INDEX TABLE got NUMBER
     // currently other types to udt not supported
-    ret = OB_ERR_UNEXPECTED;
+    ret = OB_ERR_INVALID_TYPE_FOR_OP;
     LOG_WARN_RET(ret, "not expected obj type convert", K(in_obj_meta), K(out_obj_meta),
       K(out_obj_meta.get_subschema_id()), K(expr.extra_));
   }
@@ -7707,7 +7707,7 @@ int cast_udt_to_other_not_support(const sql::ObExpr &expr, sql::ObEvalCtx &ctx,
     // other udts
     // ORA-00932: inconsistent datatypes: expected PLSQL INDEX TABLE got NUMBER
     // currently other types to udt not supported
-    ret = OB_ERR_UNEXPECTED;
+    ret = OB_ERR_INVALID_TYPE_FOR_OP;
     LOG_WARN_RET(ret, "not expected obj type convert", K(in_obj_meta), K(out_obj_meta),
       K(out_obj_meta.get_subschema_id()), K(expr.extra_));
   }
diff --git a/src/sql/engine/expr/ob_expr_xml_serialize.cpp b/src/sql/engine/expr/ob_expr_xml_serialize.cpp
index c87deb7252..b2dcd4d78a 100644
--- a/src/sql/engine/expr/ob_expr_xml_serialize.cpp
+++ b/src/sql/engine/expr/ob_expr_xml_serialize.cpp
@@ -92,7 +92,7 @@ int ObExprXmlSerialize::get_dest_type(const ObExprResType as_type, ObExprResType
     ObCollationType cs_type = static_cast<ObCollationType>(parse_node.int16_values_[OB_NODE_CAST_COLL_IDX]);
     dst_type.set_type(obj_type);
     dst_type.set_collation_type(cs_type);
-    if (ob_is_varchar_type(dst_type.get_type(), dst_type.get_collation_type())) {
+    if (ob_is_varchar_type(dst_type.get_type(), dst_type.get_collation_type()) || ob_is_nvarchar2(obj_type)) {
       dst_type.set_full_length(parse_node.int32_values_[1], as_type.get_accuracy().get_length_semantics());
     } else if (ob_is_clob(dst_type.get_type(), dst_type.get_collation_type()) ||
                ob_is_blob(dst_type.get_type(), dst_type.get_collation_type())) {
diff --git a/src/sql/engine/expr/ob_expr_xmlparse.cpp b/src/sql/engine/expr/ob_expr_xmlparse.cpp
index 28bccd6cdb..2f5ea596e9 100644
--- a/src/sql/engine/expr/ob_expr_xmlparse.cpp
+++ b/src/sql/engine/expr/ob_expr_xmlparse.cpp
@@ -12,6 +12,7 @@
  */
 
 #include "ob_expr_xmlparse.h"
+#include "sql/engine/ob_exec_context.h"
 #include "ob_expr_xml_func_helper.h"
 
 #define USING_LOG_PREFIX SQL_ENG