Oracle Archivelog Mode
Oracle Database lets you save filled groups of redo log files to one or more offline destinations, known collectively as the archived redo log, or more simply the archive log. The process of turning redo log files into archived redo log files is called archiving. This process is only possible if the database is running in ARCHIVELOGmode.
By default, database runs in no archivelog mode. You must enable it to save the redolog files into different location.
Checking Archivelog Mode
Use below command to check the archivelog mode inside the oracle database
SQL> archive log list;
You can also use below command
SQL> SELECT LOG_MODE FROM SYS.V$DATABASE;
Set Archivelog Destination
You must set a destination for archivelog files
SQL> alter system set log_archive_dest_1='location=/u01/proddb/arch'
Enable Archivelog Mode
Please note that in order to enable archivelog mode, you must bounce the database
SQL> Shut immediate; SQL> Startup mount; SQL> alter database archivelog; SQL> alter database open; SQL> archive log list;
Disable Archivelog Mode
The database must bounced even when you want to disable archivelog mode
SQL> shut immediate; SQL> startup mount; SQL> alter database noarchivelog; SQL> alter database open; SQL> archive log list;
Performing Log Switch
While your database is running in archivelog mode, you can perform force log switch. This will archive the current redo log file and force LGWR to start over-writing other redo log member
SQL> alter system switch logfile;