MIS 2403: Introduction to Database Management

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MIS 2403 Introduction to Database Management
INSTRUCTORS NOTES

• Chapter 1 The Database
• Environment A Basic Overview
• Fall 2001
• Dr. Richard S. Segall

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Welcome to MIS 2403!

• Learning Objectives
• Database skills
• Understanding Designing databases
• Intro to SQL (Oracle)
• Modeling Analysis of databases
• Business skills
• Communication
• Teamwork skills
• Writing and presentation skills

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MIS 2403 - Topical Outline

• Part One - Transaction Focus
• Introduction and Database environment
• Data Modeling, normalization, set of relations
• Database implementation
• Part Two - Analytical Focus
• Entity-Relationship Diagrams (ERD)
• Structured Query Language (SQL)
• ORACLE creation of tables and queries

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Basic Concepts and Definitions

• Database
• An organized collection of logically related
  data.
• DATA
• Facts that can be recorded and stored using
  computer media
• But, now we also store objects
• documents, photographic images, video clips
• they possess state, behavior and identity

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Data versus Information

• INFORMATION
• Data that has been placed in a context
• Data that has been PROCESSED/summarized
• Typically presented in report form
• Definition of Information
• Data that has been processed in such a way that
  it can increase the knowledge of the person who
  uses it.

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Which is more useful?
OR
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MetaData

• Data that describe the properties or
  characteristics of other data
• Examples of metadata in databases
• Data name
• Data type
• Data length
• Data minimum maximum values
• MetaData allow database designers and users to
  understand what data exist, means, and what the
  distinctions are between similar data types

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Traditional File Processing

• Used before we had databases
• Still widely used today, including backup of
  database systems
• Disadvantages to file processing
• program-data dependence
• duplication of data
• limited data sharing
• lengthy development times
• excessive program maintenance

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The Database Approach

• Enterprise Data Model
• Relational Databases
• Implementing Relational Databases
• Database Applications (p.14)will use notation in
  Chap 2 HW of PE5(c),p.73
• Create (C)
• Read (R)
• Update (U)
• Delete (D)

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Types Of Database Applications

• 1. Personal Computer Databases
• 2. Workgroup Databases
• 3. Department Databases
• 4. Enterprise Databases

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Types of DB Applications

• 1. Personal Computer Databases
• support one user, stand alone computer
• salesperson with a laptop
• keeps own customer contact information
• data not easily shared

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2. Workgroup Databases

• usually fewer than 25 people
• working on similar projects or applications
• need to share data - use a LAN

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3. Departmental Databases

• department - functional unit
• within organization
• personnel, marketing, accounting, etc.
• databases support departments activities
• architecture similar to workgroup, but may have
  applications on a separate server (three-tiered
  architecture)

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4. Enterprise Databases

• scope is the entire organization
• intended to support organization-wide operations
  and decision making
• Data warehouses
• integrated decision support database
• content derived from various operational dbs.
• Data marts

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An Enterprise Data Warehouse
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Advantages of Database Approach

• 1. Program-data independence
• 2. Minimal data redundancy
• 3. Improved data consistency
• 4. Improved data sharing
• 5. Increased productivity in application
  development

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Advantages of Database Approach - (Continued)

• 6. Enforcement of standards
• 7. Improved data quality
• 8. Improved data accessibility/responsiveness
• 9. Reduced program maintenance

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Costs and Risks of Databases

• 1. New, specialized personnel
• 2. Installation cost and complexity
• 3. Implementation cost and complexity
• 4. Conversion costs
• 5. Need for explicit backup
• 6. Organizational conflict

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Components of the Database Environment

• 1. CASE
• 2. Repository
• 3. DBMS
• 4. Database
• 5. Application programs

• 6. User interface
• 7. Data administrators
• 8. System developers
• 9. End users

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Database Management Systems (DBMS)

• DBMS
• general-purpose software system that facilitates
  the processes of defining, creating, and using
  databases.
• stores one or more databases.
• includes data and metadata that describes the
  database
• metadata - data that describe the properties or
  characteristics of other data

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DBMS Components

• Interface components
• data definition language (DDL)
• means for users to define databases
• data manipulation language (DML)
• means to develop applications and query databases
• query languages, report and form generators,
  application programming interfaces
• Data access components
• store and retrieve data from database

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Database System Environment
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DBMS Users

• (i) Access through applications
• high-volume, on-line transaction processing
• customer order entry
• airline reservations
• financial trading
• (ii) Access through software interface component
• low-volume, decision support applications
• marketing, management, financial analysis

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Some Rules for the ERD (will come back to in Chap
3)

• Create a new entity
• Whenever you have a many-to-many relationship
• Whenever you have a multivalued attribute
• Create a foreign key
• On the many side of the one-to-many relationship
• With the entity created because of MN

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More ERD Rules

• All attributes of an entity MUST be dependent on
  the key value of the attribute
• When creating entities, ask yourself
• Why is this important to the organization?
• What are its characteristics?
• What other entities is it related with?
• How is this data used (who and where)?

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The Database Design Process

• Conceptual Database Design
• Entity-Relationship Diagrams (ERDs)
• Logical Database Design
• Files, tables, or objects
• Physical Database Design
• Actual DBMS architecture

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Human Resource Needs

• 1. Data Administrators
• 2. Database Administrators
• 3. Database Analysts/Designers
• 4. Systems Analysts
• 5. Programmers

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Data Administrators

• Responsibilities
• Data Planning
• Define standards
• Determine requirements
• Conceptual Design
• Manage repository

• Qualifications
• Business knowledge
• Communication skills
• Management skills
• Technical knowledge

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2. Database Administrators

• Responsibilities
• Physical Design
• Data integrity
• Data security
• Database performance
• Backup/recovery

• Qualifications
• Technical knowledge
• Analytical skills
• DBMS skills
• Security procedures

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3. Database Analysts/Designers

• Responsibilities
• Data modeling
• Logical Design
• Business rules

• Qualifications
• Data modeling skills
• Communication skills

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4. Systems Analysts

• Responsibilities
• Determine user requirements
• Design database applications

• Qualifications
• Business knowledge
• Communication skills
• Process modeling

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5. Programmers

• Responsibilities
• Code schemas
• Program business rules
• Program database applications

• Qualifications
• Programming languages
• Analytical skills

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Chapter 1 The Database Environment

• THE END!!!