My question is this:
Suppose we have a system having 1 TB of total space.
I have created a database of 500 GB(MAXPERM) and the current perm is 300 GB.
The total effective free space on the system is 700 GB.
Can I create a database having MAXPERM 600 GB or will the system deny me this?
(For the moment let us suppose we don't want a SPOOL_RESERVE as this is just for understanding purposes)
Will the system fulfull my request or will it generate an error?
no, you can't.
At least not without reducing the max perm assigned to the 500GB database.
The PERM for a new database/user is always substracted from the database/user in the FROM option.