RMAN backup validation

Hi,
I was just reading the metalink Note:338607.1 for doing RMAN backup validation.

Executing these validation commands, eg..

RMAN> restore validate database;
RMAN> restore validate controlfile to 'c:\temp\control01.ctl';

Will this do a dummy restoration to some place....or does it just validates the backup ?

Just want to know what goes internally when these commands are fired.

Also how about the resource consumption on the machine when we issue these commands ?

did you try it and find out?

Restore Validate command would just check if all the backup related files needed for restoration are present and check if there is any possible corruption. No, It would not physically carry on restore operation.