Reverse engineering relational databases to identify and specify basic Web services with respect to service oriented computing

Service-oriented computing (SOC) is the computing paradigm that utilizes services as a fundamental building block. Services are self-describing, open components intended to support composition of distributed applications. Currently, Web services provide a standard-based realization of SOC due to: (1) the machine-readable format (XML) of their functional and nonfunctional specifications, and (2) their messaging protocols built on top of the Internet. However, how to methodologically identify, specify, design, deploy and manage a sound and complete set of Web services to move to a service-oriented architecture (SOA) is still an issue. This paper describes a process for reverse engineering relational database applications architecture into SOA architecture, where SQL statements are insulated from the applications, factored, implemented, and registered as Web services to be discovered, selected, and reused in composing e-business solutions. The process is based on two types of design patterns: schema transformation pattern and CRUD operations pattern. First, the schema transformation pattern allows an identification of the services. Then the CRUD operations pattern allows a specification of the abstract part of the identified services, namely their port types. This process is implemented as a CASE tool, which assists analysts specifying services that implement common, reusable, basic business logic and data manipulation.