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After completing this chapter, students will be able to: Become familiar with several object-persistence formats, be able to map problem domain objects to different object-persistence formats, be able to apply the steps of normalization to a relational database, be able to optimize a relational database for object storage and access,. | Chapter 10: Data Management Layer Design Objectives Become familiar with several object-persistence formats. Be able to map problem domain objects to different object-persistence formats. Be able to apply the steps of normalization to a relational database. Be able to optimize a relational database for object storage and access. Become familiar with indexes for relational databases. Be able to estimate the size of a relational database. Be able to design the data access and manipulation classes. The Data Management Layer Includes both data access and manipulation logic, and the actual design of the storage Four-step design approach Selecting the format of the storage Mapping problem-domain objects to object-persistence format optimizing the object-persistence format designing the data access & manipulation classes OBJECT PERSISTENCE FORMATS Object Persistence Formats Files (Sequential and Random) Relational databases Object-relational databases Object-oriented databases Sample File . | Chapter 10: Data Management Layer Design Objectives Become familiar with several object-persistence formats. Be able to map problem domain objects to different object-persistence formats. Be able to apply the steps of normalization to a relational database. Be able to optimize a relational database for object storage and access. Become familiar with indexes for relational databases. Be able to estimate the size of a relational database. Be able to design the data access and manipulation classes. The Data Management Layer Includes both data access and manipulation logic, and the actual design of the storage Four-step design approach Selecting the format of the storage Mapping problem-domain objects to object-persistence format optimizing the object-persistence format designing the data access & manipulation classes OBJECT PERSISTENCE FORMATS Object Persistence Formats Files (Sequential and Random) Relational databases Object-relational databases Object-oriented databases Sample File Fictitious customer database Sequential & Random Access Files Sequential access files allow sequential operations Read, write, and search Efficient for report writing Searches are not efficient because an average of 50% of records have to be accessed Two versions Ordered unordered Random Access Files Allow only random or direct file operations Good for finding and updating a specific object Inefficient report writing Application File Types Master Files Look-up files Transaction files Audit file History file Relational Databases Collection of tables Comprised of fields that define entities Primary key has unique values in each row of a table Foreign key is primary key of another table Tables related to each other Primary key field of a table is a field of another table and called a foreign key Relationship established by a foreign key of one table connecting to the primary key of another table Database Management System Software that creates and manipulates a database RDBMS is a DBMS for
