Database Systems - Chapter 1

Data

Raw facts, or facts that have not yet been processed to reveal their meaning to the end user.

Information

The result of processing raw data to reveal its meaning.

Data Management

A process that focuses on data collection, storage and retrieval.

Database

An organized collection of structured information/data stored in a computer system

Metadata

Data about data; that is, data about data characteristics and relationships..

DBMS: Database Management System

Programs that manage the database structure and control access to the data stored in the database.

Advantages Of DBMS

1. Improve Data Integration

2. Minimized Data Inconsistency

3. Improved Data Sharing

4. Improved Data Security

5. Improved Data Access

6. Improved decision making

7. Increased end-user productivity.

Data Inconsistency

A condition in which different versions of the same data stored at different locations.

Query

A question or task asked by an end user of a database in the form of SQL code.

Query Result Set

The collection of data rows returned by a query

Data Quality

Ensuring the accuracy, validity and timeliness of data.

Single User Database

A database that supports only one user at a time

Desktop Database

A single user database that runs on a personal computer

Multiuser Database

A database that supports multiple concurrent users.

Workgroup Database

A multiuser database that usually supports fewer than 50 users or is used for a specific department in an organization.

Enterprise Database

The overall company data representation which provides support for present and expected future needs

Centralized Database

A database located at a single site

Distributed Database

A logically related database that is stored in two or more physically independent sites

Cloud Database

A database that is created and maintained using cloud services, such as Microsoft Azure and Amazon AWS

General-Purpose Database

A database that contains a wide variety of data used in multiple disciplines.

Discipline Specific Database

A database that contains data focused on specific subject areas.

Operational Database

A database designed primarily to support a company's day to day operations

Analytical Database

A database focused primarily on storing historical data and business metrics used for strategic decision making

Data Warehouse

Stores historical and summarised data in a format optimised for decision support

OLAP: Online Analytical Processing

A set of tools that provide advanced data analysis for retrieving, processing, and modeling data from the data warehouse.

Business Intelligence

A set of tools and processes used to capture, collect, integrate, store and analyze data to support business decision making.

Unstructured Data

Data that exists in its original, raw state; that is, in the format in which it was collected.

Structured Data

Data that has been formatted to facilitate storage, use, and information generation

Semistructured Data

Data that has already been processed to some extent

XML: Extensible Markup Language

A metalanguage used to represent and manipulate data elements.

NoSQL

A new generation of database management system that is designed to handle rapid processing and analyzing of vast amounts of varied and unstructured data, aka Big Data.

Importance of Database Design

A well designed database facilitates data management and generates accurate and valuable information.

Data Processing (DP) Specialist

In a file system, the person responsible for developing and managing a computerized file processing system.

Logical Data Format

The way a person views data within the context of a problem domain

Physical Data Format

The way a computer "sees" (stores) data

Data Redundancy

Exists when the same data is stored unnecessarily at different places.

Data Integrity

In a relational database, a condition in which the data in the database complies with all entity and referential integrity constraints.

Data Anomaly

A data abnormality in which inconsistent changes have been made to a database. For example, an employee moves, but the address change is not corrected in all files in the database.

Database System

An organization of components that defines and regulates the collection, storage, management and use of data in a database environment.

Data Dictionary

A DBMS component that stores metadata- data about the data.

Performance Tuning

Activities that make a database perform more efficiently in terms of storage and access speed.

SQL: Structured Query Language

A powerful and flexible relational database language composed of commands that enable users to create database and table structures , perform various types of data manipulation and data administration and query the database to extract useful information.