SERQL: an ER query language supporting temporal data retrieval

A database query language, SERQL (structured entity-relationship query language), which has been developed for production use in telephone network services provisioning systems is described. The language is based on a database model extended from the basic entity-relationship model. These extensions include structured attributes, class hierarchy, and incorporation of the temporal dimension. The author also describes the temporal aspect of the network provisioning systems. The concept of orthogonal relationships between events and temporal objects is introduced in this model. Query specification for handling temporal data is discussed.<
>