Database Processing Chapter 4 The Semantic Object Model

Database Processing Chapter 4 The Semantic Object Model David M. Kroenke © 2000 Prentice Hall

Chapter 4 Semantic Objects “a named collection of attributes that sufficiently describes a distinct entity” • Student • Customer • Employee Page 74 © 2000 Prentice Hall

Attributes “define the characteristics of semantic objects” Page 75 Figure 4 -2 a © 2000 Prentice Hall

Attribute Cardinality “indicates the minimum or maximum number of instances of the attribute that must exist in order for the object to be valid” Page 76 Figure 4 -2 b © 2000 Prentice Hall

Object Instances “the occurrence of a particular semantic object” Page 77 Figure 4 -3 © 2000 Prentice Hall

Chapter 4 Object Identifier “one or more object attributes that the users employ to identify object instances” Example: Customer. ID for Customer Page 78 © 2000 Prentice Hall

Chapter 4 Domain “a description of an attribute’s possible values” Page 78 © 2000 Prentice Hall

Semantic Object View “the portion of an object that is visible to a particular application; view” Page 79 Figure 4 -4 © 2000 Prentice Hall

Chapter 4 Highline University Administration Database • Objects: – – Page 80 College Department Professor Student © 2000 Prentice Hall

Semantic Object Diagrams Page 85 Figure 4 -13 (1) © 2000 Prentice Hall

Semantic Object Diagrams Page 85 Figure 4 -13 (2) © 2000 Prentice Hall

Semantic Object Diagrams Page 85 Figure 4 -13 (3) © 2000 Prentice Hall

Semantic Object Diagrams Page 85 Figure 4 -13 (4) © 2000 Prentice Hall

Semantic Object Specifications Page 86 Figure 4 -14 (1) © 2000 Prentice Hall

Semantic Object Specifications Page 86 Figure 4 -14 (2) © 2000 Prentice Hall

Semantic Object Specifications Page 86 Figure 4 -14 (3) © 2000 Prentice Hall

Semantic Object Specifications Page 86 Figure 4 -14 (4) © 2000 Prentice Hall

Chapter 4 Domain Types • • Formula Group Simple Semantic Object Page 87 © 2000 Prentice Hall

Domain Specifications Page 87 Figure 4 -14 b © 2000 Prentice Hall

Simple Objects “contain only single-value, nonobject attributes” Page 89 Figure 4 -15 © 2000 Prentice Hall

Composite Objects “contain one or more multi-value, nonobject attributes” Page 89 Figure 4 -16 © 2000 Prentice Hall

Composite Object with Nested Groups Page 89 Figure 4 -18 © 2000 Prentice Hall

Hybrid Objects “combinations of objects of two types” Page 89 Figure 4 -22 © 2000 Prentice Hall

Association Objects “relate two (or more) objects and store data that are peculiar to that relationship” Page 99 Figure 4 -26 b © 2000 Prentice Hall

Association Object Example Page 100 Figure 4 -27 b © 2000 Prentice Hall

Subtype Object Page 101 Figure 4 -28 © 2000 Prentice Hall

Archetype/Version Object Page 104 Figure 4 -31 © 2000 Prentice Hall

Semantic vs. E-R Model Page 105 Figure 4 -33 © 2000 Prentice Hall

Semantic vs. E-R Model Page 105 Figure 4 -34 © 2000 Prentice Hall