Trying to understand RMAN's backup-sets

Hello everyone,

I'm learning about RMAN. I did a couple of backups on my test database. This database has over 300 data files (~14GB). The backup ends with 4 backup sets (each one having a backup piece). When I do "list backup" (this is 8.1.7 RMAN) I see the 4 backup sets:

backup set 1

• one backup piece
  -------------------the piece includes: like 80 datafiles...
  

backup set 2
-------- one backup piece
-------------------the piece includes: like 80 datafiles..

and so on...

My problem is: I thought that a "backup set" was the term you use when you perform a backup and that when you perform a backup...that's just one "backup set" (with one or more backup pieces). Why am I getting 4 backup sets? Shouldn't I have 1 backup set with 4 backup pieces (and all datafiles within those 4 pieces)? If I do another backup tomorrow, that's Monday bakcup-set...etc... What is it that I'm missing?

Thanks in advance!
Jose Received on Sun Nov 14 2004 - 17:59:35 CST