The GRAS Data Model

A GRAS database is a collection of graphs, called a pool. The graphs have directed, typed (labelled) edges, and typed (labelled) and attributed nodes (diane graphs - directed, node and edge labelled graphs). A node can have an arbitrary number of attributes which are handled as byte-arrays of arbitrary length.

GRAS databases can be accessed via GRAS' application programming interface. This interface offers procedures to modify the structural part of a graph (nodes and edges) as well as its data part (attribute values). It also has procedures implementing queries on nodes, attributes and edges. It is, e.g., possible to query for all nodes that are reachable by an outgoing/incoming edge from a given node. Or it is possible to find all nodes with a certain attribute value.