This is High Availability features from Oracle. When you
enable this mode redo logs will be archived instead of
overwritten. The archivelogs are stored in a seperate place usually can backed
up regularly by your standard filesystem backup system . Archive logs are
utilized by RMAN, Data Guard, Flashback and many others.
Checking the current archive mode.
SQL> SELECT LOG_MODE FROM SYS.V$DATABASE;
If it “NOARCHIVELOG” then you have to trun on ARCHIVELOG
Setup this Parameter in initialization parameter file
log_archive_dest_1='location=/u02/oradata/mybasicdb/archive'
log_archive_start=TRUE
Note: Its not required but best practice to specify
destination. You can specify as many as 10 different archive log destinations
by using the parameter’s log_archive_dest_1 through log_archive_dest_10.
Remember, if you run out of space in your archive log
destination the database will shut-down!
Start up the database in mount mode and put it in archivelog
mode.
SQL> startup mount
SQL> alter database archivelog;
SQL> alter database open;
SQL> select DEST_NAME,STATUS,DESTINATION from
V$ARCHIVE_DEST;
Read for more detail about Archive Log
http://www.mybasicknowledge.com/2012/06/archive-log-files.html
