Embodiments of the invention provide methods, systems and articles of manufacture for constructing a database abstraction model over an underlying physical database. Typically, queries of the database abstraction model are directed to queries of a model entity defined for the database abstraction model. To compose an abstract query, users select conditions evaluated using data associated with instances of the model entity. Using the database abstraction model, users may compose an abstract query according to logical or intuitive relationships among data elements stored in the underlying database. One addition to the database abstraction model is the ability to apply query criteria against related instances of a model entity. Because model entities may share a predefined relationship, embodiments of the invention allow for users to specify query criteria applied against related instances. Related instances may be identified by invoking a path function provided by the database abstraction model. A path function may be configured to return instances of the model entity that are related to an instance input to the path function.