Approach to support method invocations in object-oriented queries

An indexing technique is presented supporting an efficient evaluation of query predicates on methods. The technique is based on the precomputation of method results. The precomputed results are stored in an index that associates with a result v the list of object identifiers for which the method execution returns v. The evaluation of a predicate on the results of a method simply requires an index search. The proposed organization keeps track of changes that may influence the results of a method invocation. This mechanism is used to invalidate the precomputed results of a method. The method is recomputed again upon next invocation.