Turning Archive-log mode on and off
You can check what mode the database is in with:
SELECT LOG_MODE FROM SYS.V$DATABASE;
If you do not specify an archive-log location, it will end up going to a directory like $ORACLE_HOME/dbs – which can be quite a mess.
Check where it’s going:
SHOW PARAMETER log_archive_dest;
It would be good practice to set the location if it doesn’t show one.
To turn archive-log-mode on or off:
1 2 3
SHUTDOWN IMMEDIATE STARTUP RESTRICT SHUTDOWN
Mount the database:
ALTER DATABASE MOUNT;
Then issue one of the following:
ALTER DATABASE NOARCHIVELOG; ALTER DATABASE ARCHIVELOG;
If the location hasn’t been set yet:
ALTER SYSTEM SET LOG_ARCHIVE_DEST = "/ARC_LOCATION";
Then open the database:
ALTER DATABASE OPEN;
There might also be archivelog related entries in your PFILE, which you should also make changes to.