I am on Oracle 10GR2.
I have 1 database instance with size approximately 50GB. Today I created second instance with RMAN duplication process from the first instance. So now I have two similar DB instances with same size 50GB.
What is strange to me is size of FULL LEVEL0 backups of these databases.
Backup size of original database has approximately 22 GB, backup size of second (duplicated) instance has 7GB.
Can you explain me why? Or what should I do with original database to have same small backup size.
Executed RMAN command for backup is: BACKUP INCREMENTAL LEVEL 0 DATABASE PLUS ARCHIVELOG;
select sum(bytes)/1024/1024/1024 GB from dba_segments;
This select gives me 6,79 GB in both instances.
I did not used UNTIL TIME for duplication.
RMAN settings is same for both instances and I don't use any compression
RMAN configuration parameters are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
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 '%F'; # default
CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default