1. A metadata modeling tool to model a metadata model based on one or more databases, the metadata modeling tool comprising: a query subject builder for building query subjects in a metadata model, the query subjects being built in multiple layers of different levels of abstraction; and a diagram manager having: a diagram handler for presenting to a user a diagram representing relations between query subjects of the metadata model, and a lineage handler for changing presentation of a selected query subject to show one or more corresponding query subjects that are represented by the selected query subject.