Question
An Entity Relationship (ER)-designer is bothered by the large number of binary relationships in his ER diagram, and has the following idea. First create a
An Entity Relationship (ER)-designer is bothered by the large number of binary relationships in his ER diagram, and has the following idea. First create a new entity set called "all-entities" and connect every other entity set to "all-entities" via a generalization arrow. Now every entity belongs to the entity-set "all-entities". Next, replace all of the binary relationships by a single binary relationship called "is-related-to" that connects "all-entities" to itself. The "is-related-to" relationship has an attribute "relationship-type" so that the kind of relationship between two entities can be specified. Because "is-related-to" allows any entity to be related to any other entity, we don't need all of the different binary relationships any more. Critique this design. Is this design simpler because there are fewer binary relationships? Can it accurately model all of the relationships and constraints that might have been represented in the original diagram?
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