Lewis says the most significant overlap is in terms of provisioning and access management.

In 2005, Oracle acquired in part to counter Sun's 2003 acquisition of provisioning vendor The acquisition of Thor's provisioning tools marked Oracle's first serious entry into building an identity management platform that is now part of its Fusion middleware lineup.

Oracle and Sun also butt heads in regards to access management, where Oracle acquired Oblix in 2005 and Sun is working with its in-house developed Sun Access Manager (now part of OpenSSO Enterprise, which also includes the former Sun Federation Manager).

Oracle's lineup, in fact, is heavily laden with acquisitions including Phaos in 2004 for federation and OctetString in 2005 for virtual directories. Oracle also acquired in 2007 for its identity role management capabilities. The technology competes with , which is the fruit of Sun's acquisition of Vaau in 2007.

So the question is not only how to integrate technology from Sun and Oracle not originally designed to work together, but also how to integrate the cornucopia of third-party identity technologies scattered throughout the identity portfolios of both companies.