| In 1970, E. F. Codd published the paper "A relational model of data for large shared data banks" that introduced the relational data model for managing data. SQL, currently the most widely used relational language, was introduced in the experimental IBM database management system (DBMS) System R. Another DBMS, called INGRES, was developed at about the same time as System R (under the leadership of M. Stonebraker), and it was based on the relational database language QUEL. Since that time, inadequacies of the relational model and the need to handle more complex database issues warranted the extension of the relational model and the implementation of a DBMS that meets those needs. M. Stonebraker developed the post-relational DBMS POSTGRES based on the POSTQUEL database language. An evaluation of POSTGRES will be conducted to determine the adequacy of POSTGRES with respect to traditional relational database issues, as well as more complex issues that are considered post-relational. |
