Incremental update algorithms for materialized spatial views by using view derivation relationships

Abstract

In spatial databases, it is necessary to provide spatial view modeling facilities in order to support a variety of user's perspective views on spatial objects. Because spatial views are usually derived by complex spatial queries, it is desirable to actually materialize spatial views as opposed to being computed on demand for offering improved query performance. A main obstacle to spatial view materialization is that materialized views must be maintained in a consistent state with respect to the updates of source spatial objects. This paper defines the semantics of updating materialized spatial views in terms of the cardinality constraints of view derivation relationships between spatial view objects and source spatial objects. We also present incremental update algorithms for keeping materialized spatial views consistent by using view derivation relationships.