Database Software

Hello
I've a customer with Oracle Database 11g Release 11.2.0.3.0 - 64bit standard edition on red hat 5
the size of database segments are 166GB , its 2 RAC node configuration on ASM

there is a RMAN incremantal backup plan that keeps backups for 30 days


CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 30 DAYS;
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/RMAN_backup/B3RAC/control_%F.bak';



every 8th of a month it create a level 0 backup :
---------------------------------------------------------------------

run
{

BACKUP AS COPY
DEVICE TYPE DISK
TAG = 'MONTHLY_CONTROLFILE'
FORMAT '/RMAN_backup/B3RAC/monthly_controlfile_%d_%Y%M%D_s%s_p%p.bak'
CURRENT CONTROLFILE;

BACKUP AS COPY
DEVICE TYPE DISK
TAG = 'MONTHLY_SPFILE'
FORMAT '/RMAN_backup/B3RAC/monthly_spfile_%d_%Y%M%D_s%s_p%p.bak'
SPFILE;

BACKUP CHECK LOGICAL
AS COMPRESSED BACKUPSET
INCREMENTAL LEVEL = 0
DEVICE TYPE DISK
TAG = 'MONTHLY_DATABASE'
FORMAT '/RMAN_backup/B3RAC/monthly_database_%d_%Y%M%D_s%s_p%p.bak'
DATABASE PLUS ARCHIVELOG;

DELETE BACKUP COMPLETED BEFORE 'SYSDATE-30' DEVICE TYPE DISK;

CROSSCHECK COPY;
CROSSCHECK BACKUP;
CROSSCHECK ARCHIVELOG ALL;
DELETE NOPROMPT OBSOLETE;
DELETE NOPROMPT EXPIRED COPY;
DELETE NOPROMPT EXPIRED BACKUP;
DELETE NOPROMPT EXPIRED ARCHIVELOG ALL;

}


every 5,12,19,26 of a month it create a level 1 backup :
----------------------------------------------------------------------------------

run
{

BACKUP CHECK LOGICAL
AS COMPRESSED BACKUPSET
INCREMENTAL LEVEL = 1
DEVICE TYPE DISK
TAG = 'WEEKLY_DATABASE'
FORMAT '/RMAN_backup/B3RAC/weekly_database_%d_%Y%M%D_s%s_p%p.bak'
DATABASE PLUS ARCHIVELOG;

}


every 1-4,6-7,9-11,13-18,20-25,27-31 of a month it create a level 2 backup :
------------------------------------------------------------------------------------------------------------


run
{

BACKUP CHECK LOGICAL
AS COMPRESSED BACKUPSET
INCREMENTAL LEVEL = 2
DEVICE TYPE DISK
TAG = 'DAILY_DATABASE'
FORMAT '/RMAN_backup/B3RAC/Daily_database_%d_%Y%M%D_s%s_p%p.bak'
DATABASE PLUS ARCHIVELOG;

}


and twice in each hour (15,45) it create archive log backups:
---------------------------------------------------------------------------------------

run
{

BACKUP CHECK LOGICAL
AS COMPRESSED BACKUPSET
DEVICE TYPE DISK
TAG = 'ARCHIVE_LOG'
FORMAT '/RMAN_backup/B3RAC/archive_log_%d_%Y%M%D_s%s_p%p.bak'
ARCHIVELOG all;

}


before the end of the month the backup files already fill up 100GB disk space(even though they are compressed ) ,and customer wants to know which backup files it is possible to delete in between in order
to save disk space. for example:

1.after every weekly backup (level 1) , can I delete all the daily backups (level2) that occur before it from the last monthly backup (level0) ?
if yes what is the right command for it ?

2. since each level include the archive logs in the script: "DATABASE PLUS ARCHIVELOG" ,can I delete the archive log backups (TAG = 'ARCHIVE_LOG')
after each completion of a level backup?
if yes what is the right command for it?


3. I've many backups of control files (for example: control_c-3298337411-20120521-18.bak) , they are acquiring 11G out of the 100G. I think its due to the configuration :
"CONFIGURE CONTROLFILE AUTOBACKUP ON" . is it safe to turn autobabkup controlfile to OFF , and add to each level script excluding the archive log backup script
this command : "BACKUP CURRENT CONTROLFILE FORMAT '/RMAN_backup/B3RAC/control_%F.bak';"