Enable & Disable Archive log mode

Enable archivelog mode:

1. Verify the archive mode and the Archive destination:

a.       Verify that the database is in "No archive mode”

SQL> archive log list

Database log mode              No Archive Mode

Automatic archival             Disabled

Archive destination            USE_DB_RECOVERY_FILE_DEST

Oldest online log sequence     25

Current log sequence           27

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b.      By default, the archive destination will be flash recovery area.

SQL> show parameter recovery_file_dest

NAME                                 TYPE        VALUE

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

db_recovery_file_dest                string      /u01/app/oracle/flash_recovery

                                                 _area

db_recovery_file_dest_size           big integer 5000M

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c.       If you wish to change the archive log location, then edit “LOG_ARCHIVE_DEST_n” parameter to the path needed.

SQL> alter system set log_archive_dest_1='LOCATION=/u02/app/oracle/oradata/orcl/arch' scope = both;

System altered.

SQL> archive log list;

Database log mode              No Archive Mode

Automatic archival             Disabled

Archive destination            /u02/app/oracle/oradata/orcl/arch

Oldest online log sequence     25

Current log sequence           27

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2. Shut down the database and bring it up to “mount” mode.

SQL> shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

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SQL> startup mount

ORACLE instance started.

Total System Global Area 4275781632 bytes

Fixed Size                  2235208 bytes

Variable Size            2634024120 bytes

Database Buffers         1627389952 bytes

Redo Buffers               12132352 bytes

Database mounted.

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3. Enable the archive log mode.

SQL> alter database archivelog;

Database altered.

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4. Open the database.

SQL> alter database open;

Database altered.

SQL> archive log list

Database log mode              Archive Mode

Automatic archival             Enabled

Archive destination            /u02/app/oracle/oradata/orcl/arch

Oldest online log sequence     25

Next log sequence to archive   27

Current log sequence           27

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5. Test if the archive logs are generated in the designated location by switching log files.

SQL> alter system switch logfile;

System altered.

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Disable archivelog mode:

1. Shut down the database and bring it up to “mount” mode.

SQL> shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

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SQL> startup mount

ORACLE instance started.

Total System Global Area 4275781632 bytes

Fixed Size                  2235208 bytes

Variable Size            2634024120 bytes

Database Buffers         1627389952 bytes

Redo Buffers               12132352 bytes

Database mounted.

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2. Disable the archive log mode.

SQL> alter database noarchivelog;

Database altered.

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3. Open the database and confirm if the archive log is disabled.

SQL> alter database open;

Database altered.

SQL> archive log list

Database log mode              No Archive Mode

Automatic archival             Disabled

Archive destination            /u02/app/oracle/oradata/orcl/arch

Oldest online log sequence     30

Next log sequence to archive   31

Current log sequence           31

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