How to take a RMAN backup

first of all you need to switch the log files which are not currently switched. so first login to sqlplus as sys user and issue below commands:

>sqplplus / as sysdba
sql> alter system switch logfile;

Now login to rman using below command and issue below commands:

> rman target sys/sysadmin or >rman target=/

rman>run {
crosscheck archivelog all;
crosscheck backupset;
backup as copy current controlfile format 'control_%s.bak';
backup spfile;
backup as compressed backupset database;
backup as compressed backupset archivelog all;


DELETE NOPROMPT ARCHIVELOG ALL COMPLETED BEFORE 'sysdate -1';
DELETE NOPROMPT OBSOLETE REDUNDANCY = 1;
}exit;

How to automate the process for windows.

create a windows batch file named mysysbackup.bat
insert below commands and save file

sqlplus /nolog @c:\sqlpluscom.sql
rman target=/ cmdfile="c:\backupdb.sql"

now create sqlpluscom.sql and backupdb.sql files in c:\ drive

sqlpluscom.sql

connect / as sysdba
alter system switch logfile;
exit;

backupdb.sql

run {
crosscheck archivelog all;
crosscheck backupset;
backup as copy current controlfile format 'control_%s.bak';
backup spfile;
backup as compressed backupset database;
backup as compressed backupset archivelog all;


DELETE NOPROMPT ARCHIVELOG ALL COMPLETED BEFORE 'sysdate -1';
DELETE NOPROMPT OBSOLETE REDUNDANCY = 1;
}
exit;

now shedule the batch as a windows schedule task...