LIS 557 Database Design and Management

1
LIS 557Database Design and Management

• William Voon
• Michael Cole
• Spring '04

2
Conceptual Foundations

• 29 January 2004

3

• Measure twice, cut once.

4
What is a database?

• Database an organized body of related
  information
• A database has a purpose, so one must think
• How will it be used?
• Who will use it?

5
DB Characteristics

• Static
• Dynamic
• The data in the system is variable
• Evolving
• A growing database can be either static or dynamic

6
Domains

• Domain
• a collection of groups of data elements that
  relate to the class we want the database to
  represent.
• Taken together, the domain elements allow one to
  express every possible situation of interest
  within the database

7
A Recipe

• RU Red Ale
• All Grain Red Ale
• 6.5 Pale Malt
• 1.5 Pilsen Malt
• 6 oz Crystal Malt (800 Lovibond)
• 6 oz Crystal Malt (200 Lovibond)
• 4 oz Chocolate Malt
• 4 oz Wheat Malt
• Hops
• Northdown 4.7 HBU Bittering
• Cascade 30 minutes 6 HBU Flavor
• Mt. Hood 15 minutes 6 HBU Flavor/Aroma
• Irish Moss 15 minutes
• Wyeast 1084
• Mash grains with 1 qt. water/LB. of grains at 156
  F for 90 minutes or until conversion complete.
  Sparge with 170 F water for 60 minutes. Boil for
  15 minutes and then add the bittering hops
  (Northdown) boil for 30 minutes and add flavor
  hops (Cascade), boil for 15 minutes and add
  flavor/aroma hops (Mt. Hood) and Irish Moss, boil
  for 15 minutes chill to pitching temperature (70
  F) and pitch yeast.

8
Exercise

• Take a personal interest or hobby and identify
  the groups of elements that make up a domain, or
• Think of a special collection, what elements make
  up the domain for the collection?

9
What is a Database Management System (DBMS)?

• DataBase Management System (DBMS) a software
  system supporting the creation, use and
  maintenance of a database

10
DB vs. DBMS

• DBMS manages and exposes the database to its
  users
• The database fixes what is possible, while the
  DBMS determines what is actually available

11
What are the essential goals of a DBMS?

• What must a DBMS accomplish?
• Keep data around (persistent)
• Keep it safe
• Answer queries about data
• Ensure data integrity
• Allow modification of data
• Control access to data

12
Data and Information

• Complex question
• For our purposes
• Data an elemental unit (a number, a word) that
  requires interpretation to be meaningful
• Information stands on its own, that is one would
  say it is meaningful even without interpretation
• Notice that the context of use matters!
• - Imagine a database of historical documents

13
Why a database?

• Consider some of the things a DBMS is supposed to
  do
• Persistence
• Answers to queries
• Modification
• Why can't we do it all with information?
• Well we can, sort of .....

14
The Bank of Springfield

• Computerized, but everybody's account information
  is stored in a word processing document.
• e.g. 'Account 123 owned by Homer Simpson
  has a balance of 321.17
• Account 124 owned by Montgomery Burns has a
  balance of 1211943.07'
• Suppose it meets all of the basic criteria of a
  DBMS, so what's not so great about the BoS system?

15
Databases Pros and Cons

• Taking a data perspective has huge advantages
• Economy
• Speed
• Scalability
• But, there are also some disadvantages
• Interpretation must be supplied
• Getting answers to real questions is not so easy

16
Database Systems

• Evolution driven by the structure of the data
  relationships
• Hierarchical (tree structure)
• Network
• Relational (table structure)
• Most modern databases are relational because it
  provides good balance between data abstraction
  and performance

17
DBMS Life Cycle

• Planning What is the goal? What constraints
  exist?
• Analysis Audit user requirements
• Systems Design
• Implementation
• Maintenance