fix:

重新执行标准操作流程

Primary:

SQL>alter system set log_archive_dest_state_2='DEFER';

standby:

SQL>alter database recover manager managed standby database cancel;

- - - restart standby database

Primary:

alter system set log_archive_dest_state_2='ENABLE';

Standby:

SQL>alter database recover managed standby database disconnect;

ITPub博客

备库重启之后, 主库连接备库可能出现连接不了