在Dataguard的备库上应用日志的时候，通常有两个语句，但是这两个语句是有区别的，一个是实时应用，一个是非实时应用。

alter database recover managed standby database disconnect from session;

alter database recover managed standby database using current logfile disconnect;

测试 

--在备库上启用实时应用日志，并创建表

alter database recover managed standby database using current logfile disconnect;

--在主库上创建表

19:23:46 SYS@test>create table zbb.t3(id number);

Table created.

--在备库上查看表，立刻生效

ZBB@test_stdby>set time on

19:24:02 ZBB@test_stdby>desc t3

 Name                                      Null?    Type

 ----------------------------------------- -------- ----------------------------

 ID                                                 NUMBER

--drop掉表，在备库上启用日志应用，但不是实时的

drop table zbb.t3 purge;

alter database recover managed standby database cancel;

alter database recover managed standby database disconnect from session;

--在主库上创建表

19:26:51 SYS@test>create table zbb.t3 (id number);

Table created.

Elapsed: 00:00:00.03

--在备库上查看创建的表，表不存在

19:28:38 ZBB@test_stdby>desc zbb.t3

ERROR:

ORA-04043: object zbb.t3 does not exist

19:28:41 ZBB@test_stdby>

19:30:04 ZBB@test_stdby>desc zbb.t3

ERROR:

ORA-04043: object zbb.t3 does not exist

19:30:08 ZBB@test_stdby>

--查看是否启用实时应用

select recovery_mode from v$archive_dest_status where dest_id=2;

19:28:35 SYS@test>select recovery_mode from v$archive_dest_status where dest_id=2;

RECOVERY_MODE

-----------------------

MANAGED

Elapsed: 00:00:00.01

19:31:34 SYS@test>

SYS@test>select recovery_mode from v$archive_dest_status where dest_id=2;

RECOVERY_MODE

-----------------------

MANAGED REAL TIME APPLY

--关于recover mode的说明 。查询视图V$ARCHIVE_DEST_STATUS