GRAS: A Graph-Oriented Software Engineering Database System

office automation are usually highly interactive and deal with rather complex object structures. For the realization of these systems a nonstandard database system is needed which is able to efficiently handle different types of coarse- and fine-grained objects (like documents and paragraphs), hierarchical and non-hierarchical relations between objects (like composition-links and cross-references), and finally attributes of rather different size (like chapter numbers and bitmaps). Furthermore, this database system should support incremental computation of derived data, undo/redo of data modifications, error recovery from system crashes, and version control mechanisms. In this paper, we describe the underlying data model and the functionality of GRAS, a database system which has been designed according to the requirements mentioned above. Furthermore, we motivate our central design decisions concerning its realization, and report on experiences and applications. f(ey words: attributed graphs, graph rewriting systems, distribution, version control, derived data, software engineering environments 1