Explore Oracle Incomplete recovery-cancel-based recovery Article 1

Cancel-based Inconsistency Recovery (archive) Article 1

 

Cancellation-based recovery only applies to the following situations: loss of archived logs leads to full recovery failure; loss of data files and Unarchived redo logs (online redo logs );

 

1. Shut down the database and perform a full-database cold backup.

 

SQL> selectfile_name from dba_data_files;

 

FILE_NAME

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

/DBBak2/oradata/WWL/users01.dbf

/DBBak2/oradata/WWL/sysaux01.dbf

/DBBak2/oradata/WWL/undotbs01.dbf

/DBBak2/oradata/WWL/system01.dbf

/DBBak2/oradata/WWL/WWL001.dbf

/DBBak2/oradata/WWL/WWL002.dbf

/DBBak2/oradata/WWL/WWL003.dbf

 

7 rows selected.

 

SQL> shutdownimmediate

Database closed.

Database dismounted.

Oracle instance shut down.

 

SQL>! Mkdir/DBBak2/oradata/WWL2

 

SQL>! Cp/DBBak2/oradata/WWL/*/DBBak2/oradata/WWL2/

 

 

2. Open the database and continue using it. We can see that there are only four records in the database wwl001 during Backup.

SQL> select * fromwwl001;

 

ID NAME

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

1 jetsen

2 woo

3 prudence

4 beijin

4 rows selected.

 

3. Continue to insert data to the wwl001 table, and switch the log to archive the redo log.

SQL> insert into wwl001 values (5, 'China ');

1 row created.

 

SQL> insert into wwl001 values (6, 'America ');

1 row created.

 

SQL> commit;

Commit complete.

 

SQL> select * fromwwl001;

 

ID NAME

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

1 jetsen

2 woo

3 prudence

4 beijin

5 china

6 america

 

6 rows selected.

 

SQL>

 

SQL> alter systemswitch logfile;

System altered.

 

SQL>/

System altered.

 

SQL>/

System altered.

 

SQL>/

System altered.

 

SQL>/

System altered.

 

4. Shut down the database, simulate the loss of data files, and archive logs, so the database can only perform Inconsistency Recovery.

SQL> shutdownabort;

ORACLE instance shut down.

 

SQL>! Rm-rf/DBBak2/oradata/WWL/*. dbf

 

SQL>! Cp/DBBak2/oradata/WWL2/*. dbf/DBBak2/oradata/WWL/

 

SQL>! Cp/DBBak2/oradata/WWL2/*. dbf/DBBak2/oradata/WWL/

 

5. Execute cancel-based Incomplete recovery

SQL> startup

ORACLE instance started.

 

Total System Global Area 100663296 bytes

Fixed Size 1217884 bytes

Variable Size 88083108 bytes

Database Buffers 8388608 bytes

Redo Buffers 2973696 bytes

Database mounted.

ORA-01113: file 1 needs media recovery

ORA-01110: data file 1: '/DBBak2/oradata/WWL/system01.dbf'

 

SQL> select * fromv $ recover_file;

 

FILE # ONLINE _ error change # TIME

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

1 ONLINE 1783695 31-JUL-12

2 ONLINE 1783695 31-JUL-12

3 ONLINE 1783695 31-JUL-12

4 ONLINE 1783695 31-JUL-12

5 ONLINE 1783695 31-JUL-12

6 ONLINE 1783695 31-JUL-12

7 ONLINE 1783695 31-JUL-12

 

7 rows selected.

 

SQL> recoverdatabase until cancel;

ORA-00279: change 1783695 generated at07/31/2012 15:32:04 needed for thread 1

ORA-00289: suggestion:/DBSoft/product/10.2.0/db_1/dbs/arch/1_2_790095025.dbf

ORA-00280: change 1783695 for thread 1 isin sequence #2

 

 

Specify log: {<RET> = suggested | filename | AUTO | CANCEL}

Cancel

Media recovery canceled.

SQL>

 

SQL> select * fromv $ recover_file;

 

FILE # ONLINE _ error change # TIME

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

1 ONLINE 1783695 31-JUL-12

2 ONLINE 1783695 31-JUL-12

3 ONLINE 1783695 31-JUL-12

4 ONLINE 1783695 31-JUL-12

5 ONLINE 1783695 31-JUL-12

6 ONLINE 1783695 31-JUL-12

7 ONLINE 1783695 31-JUL-12

 

7 rows selected.

 

SQL> alterdatabase open resetlogs;

 

Database altered.

 

SQL> conn wwl/wwl

Connected.

 

SQL> select * fromwwl001;

 

ID NAME

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

1 jetsen

2 woo

3 prudence

4 beijin

 

SQL>

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