It is not real time, updates every 5 mins should be fine. But the DB2 database is real busy and its real performance based.
well, you might look over http://www.redbooks.ibm.com/abstracts/sg246828.html which discusses DB2 replication. "The Appendix C provides information about configuring federated access to Informix, which can be used as a model for federated access to other non-DB2 database, such as Oracle, MS SQL Server, Sybase, and more, using DB2 Information Integrator V8. "