To date, topology has been inexorably linked to the ArcInfo coverage data model. While build and clean operations will continue to be a key part of the ArcInfo user's repertoire for years to come, the geodatabase data model allows a new approach for topology. In the upcoming ArcGIS 8.3 release, ArcEditor and ArcInfo users will be given new tools to define, validate, and maintain topology in a geodatabase.

The integrity rules for coverage topology have equivalent rules in geodatabase topology. Yet there are a number of benefits with geodatabase topology that are not possible in the coverage model.

• Users define which layers participate in a topology.
• Multiple polygon, point, and line layers can participate in the same topology.
• There are a greater number of spatial constraints (topology rules).
• Users can specify which rules are appropriate for their data layers.
• Topology is stored in a multiuser, continuous, commercial off-the-shelf DBMS.
• Users can perform a partial build for increased performance.

In summary, the coverage model is a tightly controlled environment in which topological integrity as defined by that model is persistently maintained. On the other hand, topology in the geodatabase model offers a more flexible environment in which the user can apply a wider set of rules and constraints to maintain topological integrity.