ITM 500 Lecture 7: Week 7

• School: Ryerson University
• Department: Information Technology Management
• Course: ITM 500
• Professor: Raymond Moss

Document Summary

A composite attribute is an attribute that can be further subdivided to yield additional attributes. For example, the attribute address can be subdivided into street, city, and zip code. A simple attribute is a(cid:374) att(cid:396)i(cid:271)ute that (cid:272)a(cid:374)"t (cid:271)e su(cid:271)di(cid:448)ided. Fo(cid:396) e(cid:454)a(cid:373)ple, age, se(cid:454), and marital status would be classified as simple attributes: a single-valued attribute is an attribute that can have only a single value. For example, a person can only have one social security number: a multivalued attribute are attributes that can have many value. For example, a person may have several college degrees: a derived attribute is an attribute whose value is derived from other attributes. The derived attribute need not be physically stored within the database; it can be derived by using an algorithm. Fo(cid:396) e(cid:454)a(cid:373)ple, a(cid:374) e(cid:373)plo(cid:455)ee"s age (cid:373)a(cid:455) (cid:271)e fou(cid:374)d (cid:271)(cid:455) (cid:272)o(cid:373)pute(cid:396) the i(cid:374)tege(cid:396) (cid:448)alue of the diffe(cid:396)e(cid:374)(cid:272)e (cid:271)et(cid:449)ee(cid:374) the (cid:272)u(cid:396)(cid:396)e(cid:374)t date a(cid:374)d the e(cid:373)plo(cid:455)ee"s date of (cid:271)i(cid:396)th.