GRAS: Home

GRAS - A graph oriented database system

for (software) engineering environments

GRAS is a database system which has been designed according to the requirements of software systems for application areas like software engineering or computer integrated manufacturing. These systems are usually highly interactive and deal with rather complex object structures. For the realization of these systems a 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. GRAS is a graph-oriented database system with a client/server architecture which aims to fulfill the listed requirements.

A first prototype of the GRAS system - described in BL 85 - was already functional in 1985. Since this time gradually improving versions of GRAS have been used at different sites within the software engineering projects IPSEN Nagl 90, Rigi MK 88, CADDY EHH+ 90, MERLIN PS 92, and MELMAC DG 90.

Currently, GRAS is available in two different versions. The RGRAS System implements a multi-client/multi-server distribution as the top-most layer of its architecture. It offers interfaces for C, Modula-3, and Modula-2 and is available as a binary release. The new version of GRAS, GRAS3, supports larger graphs than RGRAS and implements its client/server distribution as a page-server, i.e. only memory pages are sent across the network. GRAS3 is available as a source code release and currently features only a Modula-3 interface. Both versions are distributed under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

If you have questions, want to give feedback, or encounter any problems with GRAS, please contact roland@i3.informatik.rwth-aachen.de.

Created by: system last modification: Wednesday 01 of December, 2004 [11:06:14 UTC] by Sven