This sounds like an OCP question. . . .
By submitting your personal information, you agree that TechTarget and its partners may contact you regarding relevant content, products and special offers.
Yes, RMAN creates separate backup sets for each group of tablespace block sizes. Suppose your default block size is 8K and and you also have one other tablespace defined with a 16K block size. RMAN will create a minimum of two backup sets, one for the 8K tablespaces and one for the 16K tablespace.
Think about it this way. RMAN is copying the blocks belonging to a tablespace to the backup set. Which is easier to manage, ensuring the backup set contains blocks all of the same size or being able to mix block sizes within the backup set? RMAN places information in the beginning of the backup set that all blocks found in the set are a certain size. On recovery, RMAN can proceed block by block through the backup set. If you allowed mix block sizes in the backup set, then RMAN would have to go through a process of determining how big the next block in the backup set is. It is much easier to ensure that each block is the same size in the backupset. This may require multiple backup sets when your database is small enough to fit into one, but you're letting RMAN manage the recovery for you, so you shouldn't care how many backup sets RMAN chooses to create.
Dig Deeper on Oracle database backup and recovery
Related Q&A from Brian Peasland
Oracle expert Brian Peasland answers one reader's question about common pitfalls when connecting Oracle to outside programs.continue reading
One reader asks expert Brian Peasland a question about datafile sizes with the Oracle RMAN duplicate 10g command.continue reading
Managing parent table-child table relations in Oracle SQL environments is key to efficient programming.continue reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.