After completing this chapter, students will be able to: Relational operations unary , relational algebra operations from set theory, binary relational operations, additional relational operations , brief introduction to relational calculus. | CSC271 Database Systems Lecture # 20 Summary: Previous Lecture Phases of database SDLC Requirements collection and analysis Database design DBMS selection (optional) Application design Prototyping Building working model of a database system Purpose of prototyping includes: To identify features of a system that work well, or are inadequate To suggest improvements or even new features To clarify the users’ requirements To evaluate feasibility of a particular system design Types of prototyping Requirements prototyping Evolutionary prototyping Implementation Physical realization of the database and application designs Use DDL to create database schemas and empty database files Use DDL to create any specified user views Use 3GL or 4GL to create the application programs, this will include the database transactions implemented using the DML, possibly embedded in a host programming language Data Conversion and Loading Transferring any existing data into new database and converting any existing applications to run on new database Only required when new database system is replacing an old system DBMS normally has utility that loads existing files into new database May be possible to convert and use application programs from old system for use by new system Testing Process of running the database system with intent of finding errors Use carefully planned test strategies and realistic data Testing cannot show absence of faults; it can show only that software faults are present Demonstrates that database and application programs appear to be working according to requirements Should also test usability of system Evaluation conducted against a usability specification Evaluation Criteria Examples of the criteria that can be used to conduct the evaluation include: Learnability Performance Robustness Recoverability Adaptability Operational Maintenance Process of monitoring and maintaining database system following installation Monitoring performance of system If performance falls, . | CSC271 Database Systems Lecture # 20 Summary: Previous Lecture Phases of database SDLC Requirements collection and analysis Database design DBMS selection (optional) Application design Prototyping Building working model of a database system Purpose of prototyping includes: To identify features of a system that work well, or are inadequate To suggest improvements or even new features To clarify the users’ requirements To evaluate feasibility of a particular system design Types of prototyping Requirements prototyping Evolutionary prototyping Implementation Physical realization of the database and application designs Use DDL to create database schemas and empty database files Use DDL to create any specified user views Use 3GL or 4GL to create the application programs, this will include the database transactions implemented using the DML, possibly embedded in a host programming language Data Conversion and Loading Transferring any existing data into new database and converting any .
