Xmas is an extensible main-memory storage system for high-performance embedded database applications. Xmas not only provides the core functionality of DBMS, such as data persistence, crash recovery, and concurrency control, but also pursues an extensible architecture to meet the requirements from various application areas. One crucial aspect of such extensibility is that an application developer can compose application-specific, high-level operations with a basic set of operations provided by the system. Called composite actions in Xmas, these operations are processed by a customized Xmas server with minimum interaction with application processes, thus improving the overall performance. This paper first presents the architecture and functionality of Xmas, and then demonstrates a simulation of mobile communication service.

This paper presents the architecture of Xmas, an extensible mainmemory storage system for high-performance and real-time database applications.Xmas not only provides the core functionality of a DBMS, such as data persistence, concurrency control, and crash recovery, but aIso has an extensible architecture to deal with requirements from various applications.One crucial aspect of such extensibility is that an application developer can compose applicationspecific, high-level operations with a basic set of operations provided by the system.CalIed composite actions in Xmas, these operations are processed by a customized Xmar server with minimum interaction with application processes, thus increasing the overall performance.