diff --git a/src/sql/ob_select_stmt_printer.cpp b/src/sql/ob_select_stmt_printer.cpp
index 824a31b552..125659da1d 100644
--- a/src/sql/ob_select_stmt_printer.cpp
+++ b/src/sql/ob_select_stmt_printer.cpp
@@ -768,8 +768,23 @@ int ObSelectStmtPrinter::print_order_by()
         const OrderItem &order_item = select_stmt->get_order_item(i);
         ObRawExpr *order_expr = order_item.expr_;
         int64_t sel_item_pos = -1;
-        for (int64_t j = 0; j < select_stmt->get_select_item_size(); ++j) {
-          if (order_item.expr_ == select_stmt->get_select_item(j).expr_) {
+        if (OB_ISNULL(order_expr)) {
+          ret = OB_ERR_UNEXPECTED;
+          LOG_WARN("unexpected null", K(ret));
+        } else if (T_FUN_SYS_CAST == order_expr->get_expr_type() &&
+                   CM_IS_IMPLICIT_CAST(order_expr->get_extra())) {
+          order_expr = order_expr->get_param_expr(0);
+        }
+        for (int64_t j = 0; OB_SUCC(ret) && j < select_stmt->get_select_item_size(); ++j) {
+          ObRawExpr *select_expr = select_stmt->get_select_item(j).expr_;
+          if (OB_ISNULL(select_expr)) {
+            ret = OB_ERR_UNEXPECTED;
+            LOG_WARN("unexpected null", K(ret));
+          } else if (T_FUN_SYS_CAST == select_expr->get_expr_type() &&
+                     CM_IS_IMPLICIT_CAST(select_expr->get_extra())) {
+            select_expr = select_expr->get_param_expr(0);
+          }
+          if (order_expr == select_expr) {
             sel_item_pos = j + 1;
             break;
           }
diff --git a/src/sql/rewrite/ob_transform_min_max.cpp b/src/sql/rewrite/ob_transform_min_max.cpp
index 9c5610d8fd..b007782082 100644
--- a/src/sql/rewrite/ob_transform_min_max.cpp
+++ b/src/sql/rewrite/ob_transform_min_max.cpp
@@ -82,6 +82,7 @@ int ObTransformMinMax::check_transform_validity(ObSelectStmt *select_stmt,
   int ret = OB_SUCCESS;
   const ObRawExpr *select_expr = NULL;
   is_valid = false;
+  bool invalid_for_dblink = false;
   if (OB_ISNULL(select_stmt)) {
     ret = OB_ERR_UNEXPECTED;
     LOG_WARN("unexpected null", K(ret), K(select_stmt));
@@ -95,7 +96,13 @@ int ObTransformMinMax::check_transform_validity(ObSelectStmt *select_stmt,
              || select_stmt->get_aggr_item_size() != 1) {
     //do nothing
     OPT_TRACE("not a simple query");
-  } else if (OB_FAIL(is_valid_select_list(*select_stmt, select_expr, is_valid))) {
+  } else if (OB_FAIL(ObTransformUtils::check_stmt_from_one_dblink(select_stmt, invalid_for_dblink))) {
+    LOG_WARN("failed to check if all tables from one dblink", K(ret));
+  } else if (invalid_for_dblink) {
+    is_valid = false;
+    // do not transform,
+    // for compatibility with Oracle before 12c
+  }  else if (OB_FAIL(is_valid_select_list(*select_stmt, select_expr, is_valid))) {
     LOG_WARN("failed to check is valid select list", K(ret));
   } else if (!is_valid) {
     //do nothing