How to Enable ARCHIVELOG mode

How to Enable ARCHIVELOG mode


Benefits of ARCHIVELOG mode.



1. We can able to take database backup ONLINE.
2. No Need to Down Oracle DB Server
3. We can better Manage our Backup Policy through RMAN
4. Limited DBA task
5. We can able to RECOVER our database point-in-time



How can enable ARCHIVELOG MODE in 9iR1.


When we create new database then database is created NOARCHIVELOG mode by default.

shutdown database


SQL>shutdown immediate;


Edit below parameters in pfile(init.ora) file.


1. LOG_ARCHIVE_START=TRUE


Create New SPFILE from Modified pfile(init.ora)


SQL> create SPFILE from PFILE;


Startup Database in Mount Mode


SQL> startup mount;


Change Database log mode from NOARCHIVELOG to ARCHIVELOG


SQL> alter database archivelog;


Open DB for normal use


SQL> alter database open;


check archive log status


Database log mode Archive Mode
Automatic archival Enabled
Archive destination C:\Oracle\product\RDBMS
Oldest online log sequence 0
Next log sequence to archive 1
Current log sequence 1



Default Archivelog destination is :$ORACLE_HOME/rdbms.




How can enable ARCHIVELOG MODE in 10gr1



In 10g Archivelog mode enabling is easy becuase we need to just turn DB log mode and archive log is automatic start.


shutdown database


SQL> shutdown immediate;


startup database in mount mode


SQL> startup mount;


Change DB log mode


SQL> alter database archivelog;


Open DB for normal use


SQL> alter database open;


check archivelog status


SQL> archive log list


Default Archive log destination.


1. 10g introduce new feature called FRA (flashback recovery area) so all archivelog files created in FRA.

2. If your not using FRA then all files created in $ORACLE_HOME/database


We can check database archivelog mode through below query


SQL> select log_mode from v$database;
or
SQL> archive log list