Evolving database management systems (DBMS) towards more flexibility in functionality, adaptation to changing requirements, and extensions with new or different components, is a challenging task. Although many approaches have tried to come up with a flexible architecture, thereis no architectural framework that is generally applicable to provide tailor-made data management and can directly integrate existing application functionality. We discuss an alternative database architecture that enables more lightweight systems by decomposing the functionality into services and have the service granularity drive the functionality. We propose a service-oriented DBMS architecture which provides the necessary flexibility and extensibility for general-purpose usage scenarios. For that we present a generic storage service system to illustrate our approach.