dataguard主备切换（无损切换switchover） - 数据库编程

> select open_mode,switchover_status,database_role from v$database;

OPEN_MODE SWITCHOVER_STATUS DATABASE_ROLE
-------------------- -------------------- ----------------
READ ONLY WITH APPLY NOT ALLOWED PHYSICAL STANDBY
SQL> select max(sequence#) from v$archived_log;

MAX(SEQUENCE#)
--------------
153
dg2：
SQL> select open_mode,switchover_status,database_role from v$database;

OPEN_MODE SWITCHOVER_STATUS DATABASE_ROLE
-------------------- -------------------- ----------------
READ WRITE TO STANDBY PRIMARY

dataguard主备切换（无损切换switchover）(二)