1) can rman backup information will be stored in both controlfile and catalog db at a time ? ( if target db is registered in catalog db)
2) how to know if db is only using controlfile for storing rman backup operations.
3) how to check if database is configured to use catalog db for rman operations ?
4) rman backup database plus archivelog;
will this command backups only archivelogs after start of backup operation (or) backup older files also which exists in archive destination.
1. RMAN Backup information is always written to the controlfile. If you are using a catalog, it will be written to the catalog in addition to the controlfile --- i.e. to both locations. However, retention of information in the controlfile is generally subject to the lower of controlfile_record_keep_time or the number of slots available in the controlfile while retention of information in the catalog can be and is generally much larger.
2. You can't know, from the database itself, whether it is writing to catalog schema or not. You can query the database's V$ views for information that is in the controlfile.
3. The database doesn't store information about whether a catalog is being used or not -- it doesn't know. You have to connect to the catalog to query for information about the target database's backups.
Remember : When you start RMAN, you must explicitly provide the CATALOG location (username/password@catalog_instance) otherwise, the default is NOCATALOG.
4. BACKUP DATABASE PLUS ARCHIVELOG will also backup Archivelogs that are present and were generated before the database backup began.