University of Sunderland COM 220 Lecture Three Slide 1 Database Application Lifecycle

University of Sunderland COM 220 Lecture Three Slide 2 DATABASE PLANNING SYSTEMS DEFINITION REQ’MENTS ANALYSIS IMPLEMENTATION DB Design CONCEPTUAL DESIGNLOGICAL DESIGNPHYSICAL DESIGNAPPLICATION DESIGN DBMS SELECTIONPROTOTYPING DATA LOADINGTESTINGMAINTENANCE Database Application Lifecycle

University of Sunderland COM 220 Lecture Three Slide 3 Planning factors. Identify planning objectives Planning

University of Sunderland COM 220 Lecture Three Slide 4 Identify boundaries Identify interfaces within organisation System Definition

University of Sunderland COM 220 Lecture Three Slide 5 Information gathering Use of requirements specification techniques –SAD Requirements Analysis

University of Sunderland COM 220 Lecture Three Slide 6 MAIN AIMS To represent data & relationships required by users and applications To provide a data model which supports transactions to specify a design that meets performance requirements Database Design

University of Sunderland COM 220 Lecture Three Slide 7 Phases of database Design Three main phases: –Conceptual Database Design –Logical database design –Physical Database Design

University of Sunderland COM 220 Lecture Three Slide 8 Conceptual Database Design Create a conceptual data model Independent of any implementation details Based on user requirements specification –assists in understanding data –facilitates communication

University of Sunderland COM 220 Lecture Three Slide 9 Logical database design The data model created in the previous phase is refined At this point you know which type of DBMS you will implementing in - e.g. relational, object-oriented etc (but not the actual DBMS) Test the correctness of the data model through normalisation

University of Sunderland COM 220 Lecture Three Slide 10 HOW to physically implement: –derive tables & constraints –identify storage structures and access methods –design security features Physical Database Design

University of Sunderland COM 220 Lecture Three Slide 11 Define terms of reference Produce shortlist Evaluate products Recommend selection and produce report Database selection

University of Sunderland COM 220 Lecture Three Slide 12 Design transactions –data to be used by transactions –functions of the transactions –output of transactions –programs Design human interface –various guidelines Application Design

University of Sunderland COM 220 Lecture Three Slide 13 Building a working model Used to check interpretation of requirements Inexpensive & quick to build Prototyping

University of Sunderland COM 220 Lecture Three Slide 14 Database created using DDL Implement application programs using selected language Implement security & integrity controls Implementation

University of Sunderland COM 220 Lecture Three Slide 15 Transfer any existing data Insert any new data Data Loading/Conversion

University of Sunderland COM 220 Lecture Three Slide 16 The process of executing the application programs with the intention of finding errors. Testing

University of Sunderland COM 220 Lecture Three Slide 17 Monitoring Performance Maintaining & Upgrading Maintenance

University of Sunderland COM 220 Lecture Three Slide 18 Further Reading Lifecycle – Connolly & Begg, 3 rd and 4 th edition, chapter 9 Conceptual Database Design – Connolly & Begg, 3 rd edition, chapter 14 – Connolly & Begg, 4 th edition, chapter 15 Logical Database Design – Connolly & Begg, 3 rd edition, chapter 15 – Connolly & Begg, 4 th edition, chapter 16 Next Week –Data Modelling & Normalisation