Introduction to databases and data modeling

• DATA: The term that means groups of information that represent the qualitative or quantitative attributes of a variable or set of variables.
• INFORMATION: defined as a refined or processed data that has been transformed into meaningful and useful form of data for specific users.
• A database is a collection of information that is organized so that it can easily be accessed, managed and updated.
• DATABASE MANAGEMENT SYSTEM: It is a collection of interrelated data and a set of programs to access the data.
• A database system consists of:

  Database

  DBMS

  Application Program
• Database System Components are:

  Data

  Hardware

  Software

  User
• A database environment is a collective system of components that comprise and regulates the group of data, management, and use of data. Which consist of software, hardware, people, techniques of handling database, and the data also.
• File System Data Processing: It is a job of updating, sorting, or validating a data file.
• A file is a chunk of data.
• 1960 - File Processing Systems
• 1970 - Hierarchical and network
• 1980 - Relational Database was developed by Dr. E.F. Codd
• 1990 - Object-oriented database(large amount of structured and unstructured data)
• 2000 - multi-tier, client-server, distributed environments, web-based, data mining
• Personal Database - PC'S, PDAs, cellphones used in special situations where there is a need to share data among users.
• Workgroup Database - designed to support collaboration in a small team (less than 25 people)
• Department Database - typically larger than a workgroup (25-100 people) and more diverse range of functions.
• Enterprise Database - Scope of the whole organization
• Hierarchical Database - The most intuitive way to visualize this type of relationship is by visualizing an upside down tree of data. In this tree, a single table acts as the "root" of the database from which other tables "branch" out.
• Network Database - This model solves the problem of data redundancy by representing relationships in terms of sets rather than hierarchy.