MGT430 week3

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Tonights Agenda

• Web Articles Internet Link
• Hardware hands on
• Database overview
• Database creation

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Database Terminology

• Character single character
• Field group of characters (e.g. name) which
  represents an attribute of some entity
• Record a grouping of related fields fixed
  variable length
• File (or Table) a group of related records
• Database an integrated collection of logically
  related data elements objects

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Database terminology (cont.)

• Entity
• Attributes
• Relations
• (ERD entity relationship diagrams)
• Relational vs. Object-Oriented

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Database Management Systems (DBMS)

• DBMS are a software interface between users
  databases
• DBMS are used to control how databases are
  Created, interrogated, maintained, and how DB
  apps are develop

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Database Management Approach

• Updating Maintaining shared data for an
  organization.
• Providing this data as needed by end users by
  using apps that share this data.
• Provide an inquiry/response report capability
  through DBMS software so end users can get the
  info they need, when they need it, and in a way
  that is useful.

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Objectives of . . . Database Management Systems
(DBMS)

• Integrating databases
• Reducing redundancy
• Sharing information
• Maintaining integrity
• Enabling database evolution

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Database development

• Development done by DBAs Database
  Administrators
• Data Dictionary data about data in DB called
  metadata --- active vs. passive
• Process
• Planning
• Analysis/Requirements
• Conceptual Design
• Logical Design
• Physical Design

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Querying a Database

• Database Interrogation via a query language or
  report generator
• SQL (Structured Query Language) Select .. From
  .. Where ..
• Graphical Natural Language queries e.g. What
  customers didnt have any orders last month?

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Types of Databases

• Operational include subject area dbs,
  transaction dbs, production dbs
• Distributed improves performance security
  updating is big challenge
• External WWW, hypermedia, etc.
• Data Warehouses central storage
• Data Marts centralized logically
• Data Mining looking for data trends to gain
  strategic advantage -- (OLAP) Online Analytical
  Processing
• Hypermedia database multimedia files

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Database Structures

• Hierarchical one to many
• Network many to many
• Relational most popular -- all data in tables
  ties to any related data in db
• Multidimensional relational plus logical
  subdivisions
• Object-oriented key new concept in multi-media
  web-based technolgies (entity attributes
  encapsulation of operations properties
  inheritance)

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Accessing Databases

• Key fields primary key (id field) for relating
  data -- old way was pointers
• Sequential Access records ordered logically
  can be fast but slow too
• Direct Access no order
• Key transformation -- index
• Indexed sequenetial access method

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Database administration

• Planning
• Design
• Creation
• Maintenance
• Analysis of usage
• Security
• Backups contingency planning

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Demonstration

• We will use Microsoft Access to construct a
  simple database.
• Add sample data to the database
• Display database data
• Construct and run simple queries
• Compare and contrast the use of Access and Excel.

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