Lecture 11 - System Development

Database

A collection of data organized to enable efficient access, retrieval, and use.

Data vs. Information

Data is raw, unprocessed input.

Information is processed data that is meaningful and useful.

Database Management System (DBMS)

Software designed to create, manage, and interact with databases.

Primary Key

A field that uniquely identifies each record in a data file or table.

Data Hierarchy

The organization of data into levels, including character, field, record, and data file.

File Processing Systems

Older systems where each department maintained separate data files, leading to redundancy and inconsistency.

Database Approach

A modern method of managing data that centralizes it in a database to reduce redundancy and improve integrity.

Data Validation

Techniques used to check the accuracy and integrity of data entered into the database.

Operational Feasibility

Determines if a system is usable and acceptable to users and the organization.

Analysis Phase

The second phase of the SDLC focusing on understanding the current system and gathering requirements.

Acceptance Testing

Final testing conducted by users to verify the system meets their requirements.

SQL (Structured Query Language)

A standard query language used for managing and manipulating relational databases.

Object-Oriented Programming (OOP)

A programming paradigm that organizes software design around data, or objects, rather than functions and logic.

Integrated Development Environment (IDE)

A software application providing comprehensive facilities to programmers for software development.

4GL (Fourth-Generation Language)

A non-procedural programming language that enables users to interact with databases more easily.

Application Development Tool

Software applications that provide tools and environments for creating and distributing software applications.

Data Dictionary

A central repository containing metadata about each data element in the database.

Phased Approach

Dividing a project into distinct phases for easier management and control.

Programming Language Classification

Categories of programming languages based on their level of abstraction and use cases.

File Maintenance

The process of keeping data in a database updated and accurate.

Testing

Evaluating the system to ensure it functions correctly and meets user needs.

Scripting Languages

Languages used for automating tasks, typically executed line by line.

Backup and Recovery

Methods used to safeguard data and restore it in case of data loss.

Macros

Sequences of commands or keystrokes recorded to automate repetitive tasks.

Web Development Tools

Languages and applications used for developing webpages and web applications.

Character

A single letter, number, or symbol represented by one byte of data.

Field

A combination of characters that represent a specific attribute of an entity.

Record

A collection of related fields that describe a single instance of an entity.

Data File (Table)

A collection of related records within a database.

Data Redundancy

The unnecessary duplication of data in multiple files.

Data Isolation

The difficulty of sharing data due to its separate storage in different files.

Improved Data Integrity

Ensuring data consistency across various applications in a centralized database.

User Involvement

The process of actively including users in system development to meet their needs.

Documentation

The comprehensive capture of information about the system throughout the development lifecycle.

Query by Example (QBE)

A graphical interface that helps users to create queries without writing code.

Joint Application Development (JAD) Sessions

Collaborative workshops for defining system requirements and design options.

Direct Conversion

Replacing the old system with the new system immediately.

Parallel Conversion

Operating the old and new systems simultaneously for a period time.

Phased Conversion

Implementing the new system in stages or modules.

Pilot Conversion

Testing the new system in a small group before full rollout.

Compilers vs. Interpreters

Compilers translate the entire code at once, while interpreters execute code line by line.

Object

An encapsulation of data and the methods that operate on that data in OOP.

Query Languages

Languages specifically designed for managing and querying databases.

Programming Language

A formal language of instructions that programmers use to communicate with computers.

System Monitoring

The process of tracking system performance to ensure efficient operation.

Data Models

Conceptual representations of how data is organized and related in a database.

Statistical Analysis

A method of data interpretation focusing on data trends and patterns.

Web Services

Services offered over the web that allow applications to communicate with one another.

Economic Feasibility

The assessment of whether the benefits of a system justify its costs.

Backup

Creating regular copies of data to restore it in case of loss.

Functionality

The range of operations that can be run on a system.

User Manuals

Documents providing instructions on how to use the system.

Transaction Logs

Records of all changes made to the database to help with recovery efforts.