Database System Concepts

Contents

Chapter 1 Introduction

Database-management system (DBMS)

• database
• programs to access the database

Two modes in which databases are used

• Online transaction processing
• Data analytics

Purpose of Database Systems

Comparing to file-processing system

A file-processing system has disadvantages:

• Data redundancy and inconsistency
• Difficulty in accessing data: Conventional file-processing environments do not allow needed data to be retrieved in a convenient and efficient manner
• Data isolation: data are scattered in various files
• Integrity problems: enforce constraints
• Atomicity problems: transaction
• Concurrent-access anomalies