Extending Schema Evolution to Handle Object Models with Relationships
Kajal T. Claypool, Elke Angelika Rundensteiner, George T. Heineman · 1999
Relationships have been repeatedly identified as an important object-oriented modeling construct for advanced applications. Today most emerging modeling standards such as the ODMG object model and UML hence have some support for relationships. Similarly, current OODB systems are begining to support structural definition of relationships as well as object level management. However, no work has been done on schema evolution of an object model that has relationships. In this paper, we present the evolution taxonomy required for evolving relationships. We also examine the effect of relationships on the pre-existing taxonomy of evolution primitives that is supported by current commercial OODB systems. We provide a comprehensive contract-based solution within the SERF framework to handle the problem externally, i.e., in a layer outside the OODB system. Also as part of our work, we extend SERF to now allow for flexible evolution of relationships with user-defined semantics. Lastly, we show th...