What exactly are SDOs (Service Data Objects)?

[Ajay Dhar]

Websphere Integration Developer (WID) is an IDE from IBM that is commonly used for developing Web services. When you generate a service implementation from a WSDL, it stores the request and response objects in SDOs. Initially I thought that an SDO was just a wrapper around the actual request and response objects but I've been doing some reading online and there seems to be much more to SDOs than that. Can anyone break down what exactly an SDO is? I've read that SDOs are based on the concept of disconnected data graphs. They also have to do with Data Mediator Services. Can someone clarify what all this means?

Thanks.

[Chuck Stephanski]

EclipseLink provides the reference implementation of SDO and this is a good place to start
http://wiki.eclipse.org/EclipseLink/FAQ/WhatIsSDO