You may want to move the JAR file to a safe place and adjust the path above accordingly. Register the jar file with the databaseĬall sqlj.install_jar('file.\UUIDUDF.jar', 'UUIDUDFJAR').Create a java file named UUIDUDF.java import // for UUID class.Ensure javac the java compiler is on your path.So here I provide a sample implementation of UUID based on Java. To produce universally unique identifiers ( UUID) various well defined algorithms are available which use a combination of time or random number generation and machine unique information such as MAC addresses to produce binary strings that have a very, very low likelihood of colliding.ĭB2 does not natively support UUID, but Java does. None of these methods provide values which are unique across multiple DB2 databases or even across machines and geographies. The result is unique across the database as long as the system clock is not reset. Typically a sequence generates unique numbers within the database unless you allow it to cycle or reset it,Ī function that generates a unique CHAR(13) FOR BIT DATA (binary) string based on the current time and information about nodes in a DB2 cluster. INSERT INTO emp VALUES(DEFAULT, 'Jones', 20000) Īn identity column is typically unique within the table unless you allow it to cycle, you reset it or allow overriding of the generation by LOAD or INSERT.Ī sequence is like an identity column, but without being attached to a table. That's a column of a table which is generated automatically, typically in an ever increasing fashion.ĬREATE TABLE emp(empid INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY, DB2 provides several means to generate unique identifiers depending on ones need.
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