MySQL 8.4 Release Notes
在使用 SQL SECURITY DEFINER 视图或存储例程的复杂场景中，用户可能因为在这些对象上缺少某些额外权限而被拒绝查看其查询的跟踪。在这种情况下，跟踪将显示为空，INSUFFICIENT_PRIVILEGES 列将显示“1”。In complex scenarios where the query uses SQL SECURITY DEFINER views or stored routines, it may be that a user is denied from seeing the trace of its query because it lacks some extra privileges on those objects. In that case, the trace will be shown as empty and the INSUFFICIENT_PRIVILEGES column will show "1".