Personal databases

DATA: Raw facts; that is , facts that have not yet been processed to reveal their meaning to the end user

INFORMATION: Facts (data) that are arranged in meaningful patterns. Information consists of transformed data and facilitates decision making.

Generating information for decision making

Generating information for decision making

What is a database?

  • Instead of storing the same data in many files, data can be structured (in tables) in a database, a collection of (usually) related data tables
  • When an application needs specific data it can be retrieved from the database
  • Example: Personnel, Sales, Accounting dept
  • Sometimes referred to as a Repository of facts

Information system

  • The database is part of a larger whole known as an Information System (IS).
  • The IS provides for data collection, storage, and retrieval.
  • It also facilitated the transformation of data into information and the management of both the data and the information.

Why use a database?

  • Data constitutes the building blocks of Information (Information is produced by processing data)
  • No decision activity should take place without information
  • Good, relevant and timely information is the key to good decision making
  • Good decision making is the key to organizational survival in a global environment

Database management

  • Database is shared, integrated computer structure housing:
    • End user data
    • Metadata

  • Database Management System (DBMS)
    • Manages Database structure
    • Controls access to data
    • Contains query language

Importance of DBMS

  • Makes data management more efficient and effective
  • Query language allows quick answers to ad hoc queries
  • Provides better access to more and better-managed data
  • Promotes integrated view of organization’s operations
  • Reduces the probability of inconsistent data
Dbms manages interaction

Dbms manages interaction

Historical roots of database

  • First applications focused on clerical tasks
  • Requests for information quickly followed
  • File systems developed to address needs
    • Data organized according to expected use
    • Data Processing (DP) specialists computerized manual file systems

File terminology

  • Data
    • Raw Facts

  • Field
    • Group of characters with specific meaning

  • Record
    • Logically connected fields that describe a person, place, or thing

  • File
    • Collection of related records

Simple file system

Simple file system