Overview of Data Modeling and Database Design ORACLE’ Objectives 8-2 ¢ Describe the stages of system development ¢ List and define basic types of data relationships ¢ Define a relational database and its components ¢ Read an entity relationship diagram ¢ Translate an entity relationship diagram into a relational database design Introduction to Oracle: SQL and PL/SQL Using Procedure Builder Objectives Before you build your tables, you design your database In this lesson, you examine the data modeling process and relational database concepts, and define normalization You also translate an entity relationship model into a relational database design At the end of this lesson, you should be able to e Describe the stages of system development e List and define basic types of data relationships e Define a relational database and its components e Read an entity relationship model e Translate an entity relationship model into a relational database design Overview of Data Modeling and Database Design 8-3 ORACLE’ Overview 8-4 se Carefully consider the components of the ¢ Complete the system development cycle ¢ Model and design the database ¢ Meet the challenges to managing data with good database design database Introduction to Oracle: SQL and PL/SQL Using Procedure Builder Overview When you create a database, you need to carefully consider its components For assistance with the design, you can follow the concepts outlined in this lesson System Development Cycle In order to logically and successfully create the database objects in the Oracle7 Server, you complete the system development cycle Each stage of the cycle contains specific activities that you perform to achieve the best possible database design Database Design Database design is just one of the stages of the development cycle Through good database design, you can achieve a reliable, high-performance system Challenges to Managing Data There are many challenges you face as you design your system They range from controlling data redundancy to enhancing communications with users By meeting each of these challenges through good database design, you improve the performance of your database Overview of Data Modeling and Database Design 8-5 ORACLE’ System Development Cycle ¢ ¢ Database development — ls atop-down, systematic approach — Transforms business information requirements into an operational database — Consists of five stages Once the design is in place, you can build the database by executing SQL commands Stages of System Development Strategy and Analysis Build and Document Production 8-6 Introduction to Oracle: SQL and PL/SQL Using Procedure Builder System Development Cycle From concept to production, develop a database by using the system development cycle The cycle contains multiple stages of development This top-down, systematic approach to database development transforms business information requirements into an operational database Stages of Development Strategy and Analysis e Study and analyze the business requirements Interview users and managers to identify the information requirements Incorporate the enterprise and application mission statements as well as any future system specifications e Build models of the system Transfer the business narrative developed in the strategy and analysis phase into a graphical representation of business information needs and rules Confirm and refine the model with the analysts and experts Design e Design the database The entity relationship model maps entities to tables, attributes to columns, relationships to foreign keys, and business rules to constraints Build and Document e Build the prototype system Write and execute the commands to create the tables and supporting objects for the database e Develop user documentation, help-screen text, and operations manuals to support the use and operation of the system Transition e Refine the prototype Move an application into production with user acceptance testing, conversion of existing data, and parallel operations Make any modifications required Production e Roll out the system to the users Operate the production system Monitor its performance, and enhance and refine the system Overview of Data Modeling and Database Design 8-7 ORACLE’ Database Design 8-8 ¢ Convert a model ¢ Combine rules, judgment, and common create your design ¢ The following factors are key to database design: representation into a workable software — Performance — Integrated application — Integration with other systems — Documentation sense to and communication — Scalability — Avoid reinventing the wheel Introduction to Oracle: SQL and PL/SQL Using Procedure Builder Database Design Designing a relational database system involves converting a model into a workable software representation The entities (or objects) perceived by the user are transformed into tables in the database All forms of design involve a mixture of rules, judgements, and common sense, and relational design is no different During a design effort, your goal is to design reliable, high-performance systems using the deliverables from the analysis effort The following key factors describe in detail why you should bother to design at all Performance The initial design of a system has an enormous impact on its final performance Generally the impact is much greater than any remedial tuning Integrated Application Application systems are typically developed by teams of developers Without some design specification from which to work, developers will each build in their own style Not only does good design promote a cohesive look and feel, but it also helps ensure that all components of the resulting application system are integrated with each other Integration with Other Systems Often, there are requirements that a new system integrate with existing systems, or even with systems yet to be built Good design extends the integration benefits mentioned above into corporate or worldwide systems Documentation and Communication A major part of a designer’s job is to communicate design decisions to others At the very least, these decisions need to be documented Scalability Tackle performance issues during design rather than during production For example, developing an application in a small, controlled environment does not test real-world situations or a large set of data, factors that can reveal design flaws Avoid Reinventing the Wheel Many of the problems you will face will have been encountered by others before you Use existing successful design solutions wherever you can Overview of Data Modeling and Database Design 8-9 RN nnn Data Models > ve Model of system in clients mind H Entity model of clients model — Table model of entity model Le Le ES EEL E1 Tables on disk Introduction to Oracle: SQL and PL/SQL Using Procedure Builder ... each of these challenges through good database design, you improve the performance of your database Overview of Data Modeling and Database Design 8-5 ORACLE’ System Development Cycle ¢ ¢ Database. .. relational database design Overview of Data Modeling and Database Design 8-3 ORACLE’ Overview 8-4 se Carefully consider the components of the ¢ Complete the system development cycle ¢ Model and design. .. system Overview of Data Modeling and Database Design 8-7 ORACLE’ Database Design 8-8 ¢ Convert a model ¢ Combine rules, judgment, and common create your design ¢ The following factors are key to database