diff --git a/src/sql/ob_spi.cpp b/src/sql/ob_spi.cpp
index 8c27b8e520..c596fb6dc3 100644
--- a/src/sql/ob_spi.cpp
+++ b/src/sql/ob_spi.cpp
@@ -6269,9 +6269,6 @@ int ObSPIService::convert_obj(ObPLExecCtx *ctx,
   for (int i = 0; OB_SUCC(ret) && i < obj_array.count(); ++i) {
     ObObj &obj = obj_array.at(i);
     tmp_obj.reset();
-    if (obj.is_clob() && !(ob_is_nstring(result_types[i].get_obj_type()))) {
-      obj.set_collation_type(result_types[i].get_collation_type());
-    }
     obj.set_collation_level(result_types[i].get_collation_level());
     LOG_DEBUG("column convert", K(obj.get_meta()), K(result_types[i].get_meta_type()),
               K(current_type.at(i)), K(result_types[i].get_accuracy()));
diff --git a/src/sql/resolver/ddl/ob_create_table_resolver.cpp b/src/sql/resolver/ddl/ob_create_table_resolver.cpp
index 0d7f4da8ac..486c06d9fb 100644
--- a/src/sql/resolver/ddl/ob_create_table_resolver.cpp
+++ b/src/sql/resolver/ddl/ob_create_table_resolver.cpp
@@ -1921,6 +1921,13 @@ int ObCreateTableResolver::resolve_table_elements_from_select(const ParseNode &p
                 if (OB_FAIL(org_column->set_extended_type_info(column.get_extended_type_info()))) {
                   LOG_WARN("set enum or set info failed", K(ret), K(*expr));
                 }
+              } else if (is_oracle_mode() && column.is_xmltype()) {
+                org_column->set_sub_data_type(T_OBJ_XML);
+                // udt column is varbinary used for null bitmap
+                org_column->set_udt_set_id(gen_udt_set_id());
+                if (OB_FAIL(add_generated_hidden_column_for_udt(table_schema, *org_column))) {
+                  LOG_WARN("add udt hidden column to table_schema failed", K(ret), K(column));
+                }
               }
             }
             LOG_DEBUG("ctas oracle mode, create_table_column_count > 0,end", K(column));