DB2 now allows you to generate a unique numeric value for each row in a table. For example, an identity column can be used to generate unique primary key values. You can also port applications that use identity columns from other RDBMS vendors to DB2. See the Administration Guide: Implementation for more information.
DB2 Version 7.2 enhances identity column support in its use with load. After loading data into a table with identity columns, you can use the ALTER TABLE statement to restart the sequence of values assigned to the identity column at the correct value. See ALTER TABLE in the DB2 Release Notes for the new syntax of the ALTER TABLE statement that supports this enhancement.