Managing Schema Evolution in Hybrid XML-Relational Database Systems

Many applications and data enterprises need to change their data content and structure from time to time. The schema evolution in database systems has been studied well by the database community and several projects have been proposed for supporting schema modifications in XML and relational models individually. However, these studies do not investigate well the evolutionary process in hybrid XML-relational systems. In this paper we will investigate the schema evolution for current hybrid XML-relational systems. We will propose a taxonomy for schema evolution in a way that preserves a schema after data evolves. Finally, we proposed a general model which will be evaluated through a case study.