Abstract: The engineering database management system OSCAR employed page server architecture to meet the requirements from engineering applications. OSCAR page server mainly implemented the core transaction management functionality of a DBMS, that is, concurrency control and recovery. It provided the multi-user sharable and reliable data page services for the client side. On the basis of such services the client module can construct a full-power engineering DBMS. This paper presents the issues encountered during designing the OSCAR pager server, along with the solving methods, including the OSCAR page server functionality allocation over the physical, buffer and transaction layers, the improvement of ARIES recovery method, and the implementation scheme of write ahead log protocol in client/server environment.