diff --git a/src/sql/ob_optimizer_trace_impl.cpp b/src/sql/ob_optimizer_trace_impl.cpp
index d583c15b7b..7dca0cfcf2 100644
--- a/src/sql/ob_optimizer_trace_impl.cpp
+++ b/src/sql/ob_optimizer_trace_impl.cpp
@@ -35,7 +35,7 @@ namespace sql
 LogFileAppender::LogFileAppender()
   :allocator_("LogFileAppender"),
   identifier_(""),
-  log_file_name_("")
+  log_file_name_("OPT_TRACE")
 {
 
 }
diff --git a/src/sql/optimizer/ob_join_order.cpp b/src/sql/optimizer/ob_join_order.cpp
index 5a02ccf667..1259dc5178 100644
--- a/src/sql/optimizer/ob_join_order.cpp
+++ b/src/sql/optimizer/ob_join_order.cpp
@@ -3672,7 +3672,7 @@ int ObJoinOrder::generate_const_predicates_from_view(const ObDMLStmt *stmt,
     if (OB_ISNULL(sel_expr = child_stmt->get_select_item(idx).expr_)) {
       ret = OB_ERR_UNEXPECTED;
       LOG_WARN("get unexpected expr", K(ret), K(idx), K(sel_expr));
-    } else if (!sel_expr->is_const_expr()) {
+    } else if (!sel_expr->is_const_expr() || sel_expr->get_result_type().is_lob()) {
       //do nothing
     } else if (OB_FAIL(ObTransformUtils::is_expr_not_null(not_null_ctx,
                                                           sel_expr,