Data guard gap恢复

通过select * from v$archive_gap;或者告警日志检查可以查看是否有归档日志的裂缝

例如：

Media Recovery Waiting for thread 1 sequence 1638

Fetching gap sequence in thread 1, gap sequence 1638-1737

Completed: ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE disconnect from session

Wed Jul 13 17:36:44 2016

FAL[client]: Failed to request gap sequence

GAP - thread 1 sequence 1638-1737

DBID 1415359633 branch 887578899

FAL[client]: All defined FAL servers have been attempted.

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

Check that the CONTROL_FILE_RECORD_KEEP_TIME initialization

parameter is defined to a value that‘s sufficiently large

enough to maintain adequate log switch information to resolve

archivelog gaps.

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

恢复时等待1638的归档日志；

如果归档日志存在可以通过：

alter database register logfile ‘/db/archivelog/1_1868_887578899.dbf‘;

的方法进行注册，注册后会自动恢复

几个命令：

当前主库正常 OPEN 状态 、 备库处于日志传送状态 .

在备库停止日志传送

SQL> recover managed standby database cancel;

ALTER DATABASE RECOVER  managed standby database cancel

备库 Read-only 模式打开

SQL> alter database open read only;

备库回到日志传送模式

SQL> recover managed standby database disconnect from session;

ALTER DATABASE RECOVER  managed standby database disconnect from session;

手工令备库应用归档日志

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT FROM SESSION;

备库alter database open read only;后有两种方式，一种是

recover managed standby database disconnect from session;

这种方式不能应用备库当前的日志文件，再主库做日志切换后会应用日志；

另一种：

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT FROM SESSION;

实时应用日志文件；两边数据保证时时同步；