Effect of Platform on Storage Size of Distinct UDTs
The size of a distinct UDT value is often larger for byte-aligned format systems than it is for byte‑packed format systems. This depends on the predefined type used to define the distinct UDT. The size of some predefined types, such as all the numeric types, is not affected by the underlying platform.
The size of a distinct UDT on a byte-packed format platform is never larger than the same underlying type on byte-aligned format systems. See Database Design for details.