Enable/Disable Archive Log Mode on Oracle Database 10g/11g

itoporacledbaadmin | 14th February 2017

How are we choosing to enable or disable archivelog

Archivelog Mode

You can perform a backup when the database is online(Hot backup) and the database is offline(Cold Backup) that means if You see a problems or disasters something with your database then you’ll have the copy data and archive the log file to recover a database(current data) but it necessary, You have to reserve space for archive log and perform backup archive log as well.

No-Archivelog Mode

You can only perform a backup when the database is offline, then if You see a problem or disaster or lost something with your database then you’ll have a copy of the data but that is the last full offline backup so you don’t have archive log to recover a database(current data).

Enable Archive Log Mode

[oracle@labdbT1 ~]$ sqlplus “/as sysdba”

SQL*Plus: Release 11.2.0.1.0 Production on Fri Feb 15 11:39:46 2012

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 – 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL>

SQL> archive log list
Database log mode No Archive Mode
Automatic archival Disabled
Archive destination USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence 5
Current log sequence 7
SQL> alter system set log_archive_dest_1=’LOCATION=/home/oracle/arch’ scope = both;

System altered.

SQL> archive log list
Database log mode No Archive Mode
Automatic archival Disabled
Archive destination /home/oracle/arch
Oldest online log sequence 5
Current log sequence 7
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 3273641984 bytes
Fixed Size 2217792 bytes
Variable Size 1795164352 bytes
Database Buffers 1459617792 bytes
Redo Buffers 16642048 bytes
Database mounted.
SQL> alter database archivelog;

Database altered.

SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /home/oracle/arch
Oldest online log sequence 5
Next log sequence to archive 7
Current log sequence 7
SQL> alter database open;

Database altered.

System altered.

Disable Archive Log Mode

SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /home/oracle/arch
Oldest online log sequence 6
Next log sequence to archive 8
Current log sequence 8
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.Total System Global Area 3273641984 bytes
Fixed Size 2217792 bytes
Variable Size 1795164352 bytes
Database Buffers 1459617792 bytes
Redo Buffers 16642048 bytes
Database mounted.
SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /home/oracle/arch
Oldest online log sequence 6
Next log sequence to archive 8
Current log sequence 8
SQL> alter database noarchivelog;Database altered.SQL> archive log list
Database log mode No Archive Mode
Automatic archival Disabled
Archive destination /home/oracle/arch
Oldest online log sequence 6
Current log sequence 8
SQL> alter database open;Database altered.SQL> archive log list
Database log mode No Archive Mode
Automatic archival Disabled
Archive destination /home/oracle/arch
Oldest online log sequence 6
Current log sequence 8

647

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