Introduction

1.1 Databases

Computer-based repositories for data

Distinctive characteristics

• Large amount of data (auxiliary memory)
• Complex data organizations
• Centered around data, not processes
• Model real-world enterprises

1.2 Advantages of Databases

• Data sharing
• Privacy (authorization mechanism)
• Decreased redundancy and increased consistency
• Reliable storage of data (backup and recovery mechanisms)
• Enforcement of standards

1.3 History

• Integrated Data Store, first general-purpose DBMS, early 1960s, Charles Bachman, General Electrics
• Information Management System (IMS), late 1960s, IBM
• Relational database model, proposed in 1970, Edgar Codd, IBM’s San Jose Laboratory
• Structured Query Language (SQL), standardized in the late 1980s
• More powerful query languages, complex analysis of data, support for new data types (e.g., images), late 1980s and 1990s
• Packages which come with powerful customizable application layers
• Internet

1.4 Outline of Database Systems

• database = collection of data
• catalog = definitions for database
• database management system (DBMS) = software

1.5 Topics of Interest

• Modeling and design of databases

  Explore the issues at abstract levels, before committing to implementation

• Setting up and manipulating databases

  Programming at a logical level (e.g., SQL)

• Implementation

  Low level physical features (beyond the course scope)

1.6 Course Conduct