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EXAMPLE 1: A COMPANY WITH DEPARTMENTS, EMPLOYEES AND PROJECTS

SLIDE #15              RELATIONAL EXTENSION

Each relation is extended, to include data:

     Department relation:
     ********************
     --------------------------
     |   department | manager |
     |   ---------- |         |
     --------------------------
     |   sales      | joe     |
     |   purchasing | phil    |
     |   accounting | tom     |
     --------------------------
     
     Employee relation:
     ******************
     ----------------------------------------------------
     |employee| age of | sex of |address of|department  |
     |--------|employee|employee| employee |            |
     ----------------------------------------------------
     | fred   | 19     | m      | florida  | sales      |
     | ann    | 23     | f      | georgia  | accounting |
     ----------------------------------------------------
     
     Project relation:
     ****************
     --------------------------------------------
     |project|start date|end date  |department  |
     |-------|of project|of project|            |
     --------------------------------------------
     | 001   | feb 01 93| apr 30 93| sales      |
     | 004   | jun 01 93| jul 30 93| purchasing |
     | 006   | oct 01 93| dec 30 93| purchasing |
     --------------------------------------------