If you plan to store UUID values in a Primary Key column, then you are better off using a TSID (time-sorted unique identifier).
One such implementation is offered by the Hypersistence TSID OSS library, which provides a 64-bit TSID that’s made of two parts:
a 42-bit time component
a 22-bit random component
The random component has two parts:
a node identifier (0 to 20 bits)
a counter (2 to 22 bits)
The node identifier can be provided by the tsid.node system property when bootstrapping the application:
-Dtsid.node="12"
H. Fliegel, and R. DiEsposti. Proceedings of the 28th Annual Precise Time and Time Interval Systems and Applications Meeting, page 189--200. Reston, Virginia, (December 1996)