Enable ARCHIVELOG mode

1. Change either the binrary parameter file or the text parameter file
For pfile : manually edit the pfile to change the LOG_ARCHIVE_START value to TRUE
For spfile : Using command "ALTER SYSTEM SET LOG_ARHIVE_START=TRUE"

2. Shutdown and startup the database in mount mode

3. Using command "ALTER DATABASE ARCHIVELOG" to make the database in archivelog mode, or, using command "ALTER DATABASE NOARCHIVELOG" to disable the database archivelog mode.

4. Using command "ALTER DATABASE OPEN" to make the database open and avaliable for user connection.

5. Finished.