RE: Atomic updates in the olden days

<Birgitta>
You could also use the SQL Function GENERATE_UNIQUE which generates an
universally unique value (VarBinary), which for example includes the
Timestamp and also the IBM i Partition.
</Birgitta>

...did this change after V7R4?

the SQL reference for v7R4 contains: "The result of the function is a unique
value that includes the internal form of the
Universal Time, Coordinated (UTC) and the system serial number. The result
cannot be null."

This would produce collissions on a multi processor system. Same situation
as some years ago with GENUUID, where the documentation stated: "most likely
unique".

We've solved this by using our own function with a key_table (as Mark
mentioned) reserving a couple of numbers (for performance reasons in massive
parallel environment). Autoincrement should this provide now. Another
problem is missing numbers in a commit environment, caused by rollback of
transactions - this is another animal.

DB2 on othe (non AS400) platforms seems to be a little bit better, but it
has problems with resetting the system time as well.

D*B