Database is an organized collection of data'

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DATABASE

• Database is an organized collection of data.
• Acts as a Decision Support System
• Resource Management
• Data Accessibility
• Data Security

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Database Basics

• Databases use three main structures for
  organizing data
• Fields, which store various pieces of data
  related to a single entity.
• Records, or collections of fields relating to an
  entity.
• Tables, which are collections of related records.

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Database Basics

• The two primary types of databases are flat-file
  databases (with only one table) and relational
  databases (with multiple, related tables).
• Information Resource Management is a concept
  designed to evaluate the importance of managing
  data information.
• Successful implementation of IRM is the
  responsibility of an organizations senior
  management.

4
DBMS Basics

• A DBMS allows users to access and manage the data
  collected in a database.
• Data management tasks (all done through the DBMS)
  can be divided into three categories
• Entering data into the database.
• Sorting (rearranging) the data in the database.
• Obtaining subsets of the data for use.

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Difference b/w DB DBMS

• A database is a repository for collections of
  related data or facts.
• A database management system (DBMS) is a software
  tool that lets users add, view, and work with the
  data in a database.

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EXAMPLE DBMS
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IRM

• There are Eight(8) functions of IRM that are
  absolutely necessary.
• Operational Management
• Quality Assurance
• Communications Management
• Data Resources Management
• Project management
• Corporate-wide IS Planning
• Information Center
• System Development Maintenance

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Types of Databases

• Centralized
• In Centralized DB all data are located at a
  single site. Users at remote sites may generally
  access the DB using data communication facilities
• Greater Control over accessing updating data
  than distributed DB
• More Vulnerable to failure

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• Personal Computer DB
• Single User
• Small Org (Medium size)
• Data Isolation
• Central Computer DB
• Remote Location
• Reservation Systems
• Client/Server DB
• Large central Computers are expensive
• Front End

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Distributed

• A distributed DB is a single logical DB that is
  spread physically across computers in multiple
  locations.
• Homogeneous DB
• Heterogeneous DB

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Homogeneous DB

• The DB technology is the same or at least
  compatible at each of the location and that the
  Data at various loc is also compatible
• The computer OS used at each of the loc are the
  same or at least they are highly compatible
• The data models used at each loc are the same .
• The DB management systems used at each loc are
  the same, or at least they are compatible
• The data at the various locations have common
  definitions formats.

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Heterogeneous DB

• In most Org DB evolves over a period of time
  without careful guidance or planning.
• Different Computers O.Systems
• Different Data models DBMS are also very
  common.
• For Example one loc may have the latest
  relational DB Management Technology, while
  another location may store using conventional
  files -or older hieratical or Network DB.

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• Syntactic Differences
• (Such as different representation of data field
  at two locations)
• Semantic Differences
• ( Such as Different meanings for the term
  account at different locations)