Using a bigfile tablespaces witha block size of 32k, a datafile can be as large as 128TB, with a max database size of 8EB.A database using only smallfile tablespaces can have a max datafile size of 128GB and therefor a max db size of 8PB. because a Bigfile tablespace can only have one datafile.
Given that the max number of datafiles in a database on most platforms is 65,533 and the no of blocks in a bigfile tablespace is 2 power of 32, you can calculate the max anount of space(M) in a single Oracle database as the maximum no of datafiles(D) multiplied by the maximum number of blocks per datafile(F) multiplied by the tablespace block size (B)
The max database size, give the max block size and max no of datafiles is
65,533 datafiles * 4,294,967,296 blocks per datafile * 32,768 block size = 9,223,231,299,366,420,480= 8EB
For a small file tablespace, no of blocks in a smallfile tbs datafile is only 2 power of 22.
65,533 datafiles *4,194,304 blocks per datafile * 32,768 block size = 8PB