Generate UUIDs in DB2

Oracle (sorry to compare!) has ability to generate a UID.

We are looking for this function in DB2 Zos and LUW.

Universal Unique Identifier (UUID) -- In Oracle

Oracle sequences are frequently used to provide unique numbers for primary keys where an appropriate unique key is not available. The use of sequences can cause a problem during data migrations and replication processes where duplication of the sequences occur. The use of a Universal Unique Identifier (UUID) solves this problem as each number is unique, rather than the next value in a sequential list of numbers. In addition, the UUID can be generated within the application server layer rather than the database, negating the need for extra round-trips to query the value of sequences or automatically assigned primary key values.

A UUID is a 128-bit number used to uniquely identify an object or entity on the Internet. Depending on the specific mechanisms used, a UUID is either guaranteed to be different or is, at least, extremely likely to be different from any other UUID generated until 3400 A.D. The UUID relies upon a combination of components to ensure uniqueness. A guaranteed UUID contains a reference to the network address of the host that generated the UUID, a timestamp (a record of the precise time of a transaction), and a randomly generated component. Because the network address identifies a unique computer, and the timestamp is unique for each UUID generated from a particular host, those two components should sufficiently ensure uniqueness. However, the randomly generated element of the UUID is added as a protection against any unforseeable problem.

In this article I'll present three methods for generating UUIDs.

Using SYS_GUID()

Using Java

Using PL/SQL