Oracle backup recovery-TrialRecovery

Trialrecovery is basically similar to normal media recovery. The redo process only occurs in the memory and data changes are not written to the disk. To put it bluntly, the test media is restored.

Trial recovery is basically similar to normal media recovery. The redo process of an application only occurs in the memory and data changes are not written to the disk. To put it bluntly, the test media is restored.

1. What is Trial Recovery?

Official explanation: A trial recovery applies redo in a way similar to normal media recovery, but it never writes its changes to disk and it always rolls back its changes. Trial recovery occurs only in memory.

Trial recovery is basically similar to normal media recovery. The redo process of an application only occurs in the memory and data changes are not written to the disk. To put it bluntly, it is the test media recovery process.



How Trial Recovery works

1 By default, if the data block is damaged or encounters a similar problem, the relevant block is marked to continue the restoration, and the error message is written to the alert file.

2 when the following problem occurs, the Trial Recovery process ends.



● Memory buffer limit exceeded

● An irreparable error occurs, which cannot be solved even by marking Bad blocks, such as file loss.

● The user cancels or terminates session Restoration

● All the necessary redo operations have been applied, that is, they do not need to be restored.

When trial recovery ends, everything is restored to the original state, but the error message is recorded in the alter file. When running the test, eliminate the impact of memory on the end of the test process.



Trial Recovery statement

Recover ........ Test

For example:

Recover database test

Recover database using backup controlfile until cancel test

Recover tablespace users test

Recover database until cancel test



Note: by default, trial recovery will mark (unrestricted) Bad blocks in the memory so that the recovery process can continue. We can specify the allow n resume uption statement in recover ..... To limit the number of bad parts that can be marked.



4. Testing Process

Normal situation:

RMAN> recover database test;



Starting recover at 05-DEC-12

Using channel ORA_DISK_1

Starting media recovery

Archive log thread 1 sequence 1 is already on disk as file/Oracle/archive/zookeeper 801229657.dbf

Archive log thread 1 sequence 2 is already on disk as file/oracle/archive/1_2_801229657.dbf

Archive log thread 1 sequence 3 is already on disk as file/oracle/archive/1_3_801229657.dbf

Archive log thread 1 sequence 4 is already on disk as file/oracle/archive/4154_801229657.dbf

Archive log thread 1 sequence 5 is already on disk as file/oracle/archive/4155_801229657.dbf

Archive log thread 1 sequence 6 is already on disk as file/oracle/archive/4156_801229657.dbf

Archive log thread 1 sequence 7 is already on disk as file/oracle/archive/4107_801229657.dbf

Archive log thread 1 sequence 8 is already on disk as file/oracle/archive/4158_801229657.dbf

Archive log thread 1 sequence 9 is already on disk as file/oracle/archive/4109_801229657.dbf

Archive log thread 1 sequence 10 is already on disk as file/oracle/archive/201710_801229657.dbf

Archive log thread 1 sequence 11 is already on disk as file/oracle/archive/201711_801229657.dbf

Archive log thread 1 sequence 12 is already on disk as file/oracle/archive/201712_801229657.dbf

Archive log thread 1 sequence 13 is already on disk as file/oracle/archive/pai13_801229657.dbf

Archive log thread 1 sequence 14 is already on disk as file/oracle/archive/1_14_801229657.dbf

Archive log filename =/oracle/archive/partition limit 801229657.dbf thread = 1 sequence = 1

Archive log filename =/oracle/archive/1_2_801229657.dbf thread = 1 sequence = 2

Archive log filename =/oracle/archive/1_3_801229657.dbf thread = 1 sequence = 3

Archive log filename =/oracle/archive/ipv4_801229657.dbf thread = 1 sequence = 4

Archive log filename =/oracle/archive/logs 5_801229657.dbf thread = 1 sequence = 5

Archive log filename =/oracle/archive/ipv6_801229657.dbf thread = 1 sequence = 6

Archive log filename =/oracle/archive/logs 7_801229657.dbf thread = 1 sequence = 7

Archive log filename =/oracle/archive/export 8_801229657.dbf thread = 1 sequence = 8

Archive log filename =/oracle/archive/rj9_801229657.dbf thread = 1 sequence = 9

RMAN-11006: WARNING: test rediscovery results:

ORA-10574: Test recovery did not found upt any data block

ORA-10573: Test recovery tested redo from change 2779426987 to 2779427975

ORA-10572: Test recovery canceled due to errors

ORA-10581: Can not modify redo log header during test recovery

Media recovery complete, elapsed time: 00:00:00

Finished recover at 05-DEC-12