Streams and Sequences

Following some more investigation and testing (this Streams stuff really is a voyage of discovery for me) it turns out that sequences don't get updated via Streams.

When you think about it this makes sense - the primary purpose of Streams/replication is to have a scalable, effectively parallel system. If user A in database A is waiting for the "next sequence number" whilst user B in database B is using the sequence you have an instantly serialised system.

Now this has caused us a slight problem insofar as the application we're looking to apply Streams to (Oracle Identity Manager) uses sequences for at least some of its primary keys. The way around this is to simply use odd numbers for sequences in database A and even numbers for sequences in database B.

From a Streams instantiation point of view, since the sequences are already created in the "source" database, this means doing some altering of sequences in both ends to make sure they won't overlap (and thus violate the primary key constraints).

Annoying, but not too much of a problem.

Reference link:
AskTom article on Streams

Cheers,

Ian