از اوراکل 10g می توان با استفاده از incremental backup، گپ ایجاد شده بین بانک اصلی و دیتاگارد را برطرف کرد منتهی ابتدا می بایست این بکاپ به صورت دستی از بانک اصلی گرفته شده و سپس از بانک اصلی به کمک سیستم عامل به سرور گارد منتقل و در نهایت ریکاوری شود.

در اوراکل 12c، نقش سیستم عاملی dba حذف شده و با حداقل درگیری dba و تنها با استفاده از چند دستور ساده، گپ ایجاد شده بین بانک اصلی و دیتاگارد برطرف خواهد شد:

–in primary:

SQL> select max(sequence#),thread# from v$archived_log group by thread#; 

MAX(SEQUENCE#)    THREAD#

————– ———-

            98          1

–in stb:

SQL> select max(sequence#),thread#,applied from gv$archived_log group by thread#,applied order by thread#;

MAX(SEQUENCE#)    THREAD# APPLIED

————– ———- ———

            98          1         YES

SQL> shutdown abort

–in primary:

SQL> alter system switch logfile;

SQL> alter system switch logfile;

SQL> select max(sequence#),thread# from v$archived_log group by thread#; 

MAX(SEQUENCE#)    THREAD#

————– ———-

           101          1

!rm -rf /u01/arch/1_10*

SQL> startup mount force;

ORACLE instance started.

Total System Global Area 3154116608 bytes

Fixed Size                  3715784 bytes

Variable Size             956304696 bytes

Database Buffers         2181038080 bytes

Redo Buffers               13058048 bytes

Database mounted.

–in stb:

  SQL> startup force;

SQL>  alter database recover managed standby database;

ORA-00308: cannot open archived log ‘/u01/arch/1_100_916411681.dbf’

ORA-00308: cannot open archived log ‘/u01/arch/1_101_916411681.dbf’

SQL> startup force mount

rman target sys/sys@stb

RMAN> RECOVER DATABASE FROM SERVICE primdb NOREDO ;

Starting recover at 05-JUL-16

using target database control file instead of recovery catalog

allocated channel: ORA_DISK_1

channel ORA_DISK_1: SID=93 device type=DISK

channel ORA_DISK_1: starting incremental datafile backup set restore

channel ORA_DISK_1: using network backup set from service primdb

destination for restore of datafile 00001: /u02/oradata/usef2/datafile/system.257.916411579

channel ORA_DISK_1: restore complete, elapsed time: 00:01:06

channel ORA_DISK_1: starting incremental datafile backup set restore

channel ORA_DISK_1: using network backup set from service primdb

destination for restore of datafile 00003: /u02/oradata/usef2/datafile/sysaux.256.916411533

channel ORA_DISK_1: restore complete, elapsed time: 00:01:05

channel ORA_DISK_1: starting incremental datafile backup set restore

channel ORA_DISK_1: using network backup set from service primdb

destination for restore of datafile 00004: /u02/oradata/usef2/datafile/undotbs1.259.916411625

channel ORA_DISK_1: restore complete, elapsed time: 00:00:03

channel ORA_DISK_1: starting incremental datafile backup set restore

channel ORA_DISK_1: using network backup set from service primdb

destination for restore of datafile 00006: /u02/oradata/usef2/datafile/users.258.916411623

channel ORA_DISK_1: restore complete, elapsed time: 00:00:02

Finished recover at 05-JUL-16

STARTUP NOMOUNT force;

RMAN> RESTORE STANDBY CONTROLFILE FROM SERVICE primdb;

Starting restore at 05-JUL-16

using target database control file instead of recovery catalog

allocated channel: ORA_DISK_1

channel ORA_DISK_1: SID=362 device type=DISK

channel ORA_DISK_1: starting datafile backup set restore

channel ORA_DISK_1: using network backup set from service primdb

channel ORA_DISK_1: restoring control file

channel ORA_DISK_1: restore complete, elapsed time: 00:00:02

output file name=/u02/oradata/control01.ctl

Finished restore at 05-JUL-16

SQL> startup force;

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;

SQL> select max(sequence#),thread#,applied from gv$archived_log group by thread#,applied order by thread#;

MAX(SEQUENCE#)    THREAD# APPLIED

————– ———- ———

           108          1 YES