Server Design Arcs and Sub Entities

ER Diagram

Transformation Options for Exclusivity Supertype and subtypes TITLE Supertype Explicit subtypes Implicit subtypes Arcs MOVIE GAME

The Supertype Option Supertype TITLE # PRODUCT CODE * TITLE TITLES * TI_TYPE * TITLE . . . o CATEGORY o AUDIO o CATEGORY_CATEGORY o MINIMUM_MEMORY MOVIE * CATEGORY . . . o AUDIO Supertype GAME * CATEGORY . . . o MINIMUM MEMORY

Supertype Option

Result of Supertype Option Discriminator Column

The Explicit Subtype Option GAMES # * PRODUCT_CODE * TITLE * CATEGORY o MINIMUM_MEMORY . . . MOVIES # * PRODUCT_CODE * TITLE * CATEGORY o AUDIO . . . TITLE # PRODUCT CODE * TITLE MOVIE * CATEGORY . . . o AUDIO Explicit Subtype GAME * CATEGORY . . . o MINIMUM MEMORY

Implementing Explicit Subtypes Select the In Set check box for the subtypes only MOVIES GAMES Table Mappings In Set TITLE No Mapping --GAME Included --MOVIE Included

The Implicit Subtype Option (rare and not recommended) TITLE # PRODUCT CODE * TITLE TITLES # * PRODUCT_CODE * TITLE MOVIE * CATEGORY . . . o AUDIO MOVIES # * PRODUCT_CODE * TITLE * CATEGORY o AUDIO . . . Implicit Subtype GAMES # * PRODUCT_CODE * TITLE * CATEGORY o MINIMUM_MEMORY . . . GAME * CATEGORY . . . o MINIMUM MEMORY

Implementing Implicit Subtypes Select the In Set check box for the supertype and the subtypes TITLES GAMES Table Mappings TITLE No Mapping Included --GAME --MOVIE In Set MOVIES

The Ordinary Arc

The Result

The Arc Option (rarely applicable) TITLE # PRODUCT CODE * TITLE MOVIES # * MO_ID * CATEGORY . . . o AUDIO MOVIE * CATEGORY . . . o AUDIO TITLES # * PRODUCT_CODE * TITLE . . . o MO_MO_ID o GA_GA_ID Arc GAMES # * GA_ID * CATEGORY . . . o MINIMUM_MEMORY GAME * CATEGORY . . . o MINIMUM MEMORY

Implementing Arcs—First Run Include supertypes and subtypes Table Mappings TITLE Included --GAME --MOVIE In Set No Mapping Choose tables only Run Options Types of elements that you want to create Tables Columns Keys

Implementing Arcs—Second Run Map the arc Table Mappings TITLE Mapped --GAME --MOVIE Arc Table TITLES MOVIES GAMES Entity In Set Select tables, columns, and keys Run Options Types of elements that you want to create Tables Columns Keys

Choosing Implementation