A method and apparatus for identifying relationships among entity instances of a plurality of entities in a database. A plurality of entity reference relationship structures is accessed. Each entity reference relationship structure includes at least a pair of entity instance identifiers that identifies a relationship between entity instances of a pair of entity structures of a plurality of entity structures. All complete graphs among all subsets of the plurality of entity structures are identified. Each complete graph includes at least one edge corresponding to an entity reference relationship structure, and two vertices connected by the at least one edge that correspond to entity structures between which the entity reference relationship structure establishes a relationship. For each complete graph, all matched sets of pairs of entity instance identifiers are determined. The entity instance identifiers in each matched set are stored in association with each other in an entity relationship structure.