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Information Resources Management. January 16, 2001. Agenda. Administrivia Course Overview Database Management Systems (DBMSs) Homework #1. Administrivia. Syllabus Book Homework Web Page. Course Calendar. Eleven Homeworks Approximately one per week Exams Midterm 1 - 2/20
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Information Resources Management January 16, 2001
Agenda • Administrivia • Course Overview • Database Management Systems (DBMSs) • Homework #1
Administrivia • Syllabus • Book • Homework • Web Page
Course Calendar • Eleven Homeworks • Approximately one per week • Exams • Midterm 1 - 2/20 • Midterm 2 - 3/20 • Final - TBA • Quizzes • Up to five
Overview – Perspective • Database Design and Implementation • “Business” Perspective • IT professional in an organization
Database Design • Relational Model • Database Modeling • Evaluation Tools • Normalization
Database Implementation • SQL (Structured Query Language) • Dependability, Reliability • Architecture • Distributed Databases
Database Management Systems • Traditional File Processing Systems • Database • Comparison • Database Lifecycles • Database Management System Functions
Traditional File Processing System • Separate Files • Department • Business Function • Independent of Each Other • High Level of Program Dependence • Program contains file structure and location
Example Time Cards Sorted by Employee # Trans Master Data Entry Sort by Employee # Update Master Trans New Master Report Checks
Physical/Internal Logical/Conceptual View/External How data is stored What is stored What is used (subset) Data Abstraction (Views) Traditional file processing prevents this abstraction. Why?
Three Views of Data External (View) Client Customer Programmer Conceptual (Logical) Designer Database Administrator (DBA) Internal (Physical) Database Administrator (DBA) Tech Support
What is Needed • Physical Independence • Logical Independence
Physical Independence • Physical layout and organization of data can be changed without changing either the overall logical structure of the data or the application programs • Examples • Move data location • Move data to faster storage • Change indexing • Add a secondary key
Physical Independence External (View) Conceptual (Logical) Internal (Physical) No Resulting Change Here Change Here
Logical Independence • Non-loss changes to the logical structure can be made without changing application programs or end-user views • Examples • Change format of a field (zip from 5 to 9) • Add a new data field • Add a new table • Divide a table into two
Logical Independence External (View) Conceptual (Logical) Internal (Physical) No Resulting Change Here Change Here Coordinating Change Here
Database • organized collection of logically related data • shared collection of interrelated data designed to meet the informational needs of multiple users • data is independent of program and user views • data is stored with physical and logical independence
Database Management System (DBMS) • Software that facilitates the implementation of the database concept
Comparison(Traditional vs. Database) • Database Advantages/Traditional Disadvantages • program-data dependence • duplication • data sharing • development times • program maintenance – ripple effects • flexibility
Comparison(Traditional vs. Database) • Database Advantages/Traditional Disadvantages • security • data integrity • data as corporate resource
Comparison(Traditional vs. Database) • Traditional Advantages/Database Disadvantages • size • complexity • cost • special hardware • impact of failure • recovery
Comparison(Traditional vs. Database) • Traditional Advantages/Database Disadvantages • additional personnel • conversion costs • organizational conflict
Database Lifecycle 1. Enterprise Modeling 2. Conceptual Data Modeling 3. Logical Database Design 4. Physical Database Design and Creation 5. Database Implementation 6. Database Maintenance
People Involved • Systems analysts & designers • Database analysts & designers • Users • Programmers • Database Administrators (DBAs) • Networking experts • Other technical experts
Database Management System Functions • data storage, retrieval and update • user-accessible catalog • transaction support • concurrency control • recovery services • authorization services • support for data communication
Database Management System Functions • integrity services • types - character, number, etc. • internal validity • services to promote data independence (logical and physical) • utility services
Database Applications • Personal • one user • Workgroup • small team - LAN connected • Department/Division • multiple teams and functions • Enterprise • entire organization
In-Class Exercise • Groups of 4 • Introduce yourself • Identify a possible database of each type • Pick a speaker
In-Class Exercise • Introduce yourself and group members • Give group’s example databases • personal • workgroup • department/division • enterprise
Benefits individualized meet specific needs purchased package Drawbacks limited to no data sharing replicated data consolidation - standardization support Personal Databases
Benefits meet specific needs data shared (across group) customized “views” Drawbacks data sharing across groups replicated data security not optimal for individual DBMS cost & support Workgroup Databases
Benefits meet (specific) needs data shared Drawbacks data sharing replicated data security not optimal for individual/group performance DBMS cost & development Department Databases
Benefits meet needs data shared “mineable” consistent view to customers Drawbacks size & complexity security cost & support development standards & bureaucracy distribution & ownership Enterprise Databases
Best Database? • Personal? • Workgroup? • Department? • Enterprise?
Best Database? • Personal? • Workgroup? • Department? • Enterprise? Combination of databases that meets the needs of individuals, teams, departments, and the company
Best Database? • To the individual, it’s a personal database • To the team, it’s a workgroup database • To the department, it’s a department database • To the CEO, it’s an enterprise database • (To the DBA, it’s a headache)
Homework #1 • Data management recommendation • High-level, experience based • “glossy” vendor material • Show • alternatives • strengths/weaknesses of each • well-reasoned explanation