Oracle PL/SQL - SYS_GUID()

SYS_GUID generates and returns a globally unique identifier (RAW value) made up of 16 bytes. On most platforms, the generated identifier consists of a host identifier, a process or thread identifier of the process or thread invoking the function, and a nonrepeating value (sequence of bytes) for that process or thread.

Example:

SELECT SYS_GUID() AS "GLOBAL IDENTIFIER",EMP_ID AS "EMPLOYEE ID",NAME FROM TEMPEMP