CSD 305 Advanced Databases Database Lifecycle and DBMS

CSD 305 Advanced Databases Database Lifecycle and DBMS Selection Ref: Connolly and Begg 6 th ed. , Chapter 10 1

Lecture overview • • Database definition Requirements collection and analysis Database design DBMS selection Implementation Testing Maintenance CSD 305 Advanced Databases • Database development lifecycle 2

CSD 305 Advanced Databases Database system development lifecycle (DSDLC) 3

Database Definition • a particular job role (such as Manager or Supervisor) or • enterprise application area (such as marketing, personnel, or stock control). CSD 305 Advanced Databases • Specifying scope and boundaries of the database system and the major user views. • User view defines what is required of a database application from perspective of: 4

Requirements collection and analysis • a description of the data used; • the details of how data is to be used; • any additional requirements for the new database system. CSD 305 Advanced Databases • The process of collecting and analysing information about the part of the organization that is to be supported by the database system, and using this information to identify the requirements for the new system. 5

Requirements collection and analysis • • • Diagrams represents management of user views This approach preferred when significant overlap in requirements System not overly complex CSD 305 Advanced Databases Centralised approach 6

Database Design • The process of creating a design that will support • Three phases of database design: • Conceptual database design • independent of all physical considerations • Logical database design • Based on data model but independent of DBMS and physical considerations • (normalisation) • Physical database design. • Base relationships, file organisation and indexes • Integrity constraints, security measures CSD 305 Advanced Databases • all major application areas and user groups • any transactions required on the data • performance requirements for the system 7

CSD 305 Advanced Databases Database Design 8

CSD 305 Advanced Databases Database design – Criteria for an Optimal Data Model 9

• The selection of an appropriate DBMS to support the database system. • Undertaken at any time prior to logical design provided sufficient information is available regarding system requirements. • Performance, ease of restructuring, security and integrity constraints • Main steps to selecting a DBMS: • • determine DBMS requirements shortlist two or three products; evaluate products; recommend selection and produce report. CSD 305 Advanced Databases DBMS Selection 10

Business requirements imply DBMS requirements • strategic • tactical • resource constrained • external factors • innovation i. e. technology driven CSD 305 Advanced Databases • Business requirements 11

DBMS shortlisting and evaluating Shortlist a few products Desirable requirements CSD 305 Advanced Databases Essential DBMS Requirements 12 Evaluate shortlisted products

• Cost • Availability • Vendor support • Compatibility with existing hardware/software • Political • Existing users • Online research • https: //www. infoworld. com/category/database/ For comprehensive reviews CSD 305 Advanced Databases Essential requirements 13

CSD 305 Advanced Databases DBMS Desirable Features 14

CSD 305 Advanced Databases DBMS Desirable Features 15

Selecting a DBMS Product CSD 305 Advanced Databases For each shortlisted DBMS; for each feature group --- 16

Selecting a DBMS Product Group Rating Weighting Score Data defn. 6. 5 0. 1 0. 65 Physical defn. 5. 75 0. 25 1. 44 Accessibility 6. 00 0. 1 0. 60 Transaction handling 5. 50 0. 15 0. 825 Utilities 3. 25 0. 2 0. 65 Development 4. 50 0. 1 0. 45 Other 5. 00 0. 1 0. 50 This DBMS 5. 115 CSD 305 Advanced Databases Assemble a score for the DBMS 17 Do the same for the other shortlisted DBMSs; highest score wins

Implementation • Data conversion and loading • May be possible to convert and use application programs from old system for use by new system. CSD 305 Advanced Databases • Build the database (and applications). • Changeover 18

• Database tested as part of application testing • Verify database against the requirements e. g. response time, throughput (transactions/second) • Verify non-functional requirements e. g. backup, security, response time, throughput (transactions/second) CSD 305 Advanced Databases Testing 19

Maintenance corrective, perfective, adaptive • if performance falls, may require tuning or reorganization of the database. • Maintaining and upgrading database application (when required). • Incorporating new requirements into database application. CSD 305 Advanced Databases • Process of monitoring and maintaining system following installation. • Monitoring performance of system. 20

Operational issues • Process of operating the new system. • Technical • Human resources • Right mix of people with right skills • Training/career paths etc. • Organisational • Fault reporting/fixing procedures CSD 305 Advanced Databases • Interfacing to legacy systems • Interfacing to external systems 21

Summary CSD 305 Advanced Databases • Database System Development Lifecycle (DSDLC) • Selection of DBMS 22