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LIS 557
Database Design and
Management
William Voon
Michael Cole
Spring '04
Conceptual Foundations
29 January 2004
“Measure twice, cut once.”
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?
DB Characteristics
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Static
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Dynamic
–
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The data in the system is variable
Evolving
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A growing database can be either static or
dynamic
Domains
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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
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.
Prime with 2/3 cup corn sugar dissolved in 1 pint of boiling water.
What are the groups of elements in the domain of beer
ingredients?
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?
What is a Database Management System
(DBMS)?
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DataBase Management System (DBMS): a
software system supporting the creation, use
and maintenance of a database
DB vs. DBMS
●
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DBMS manages and exposes the database
to its users
The database fixes what is possible, while
the DBMS determines what is actually
available
What are the essential goals of a DBMS?
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What must a DBMS accomplish?
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Keep data around (persistent)
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Keep it safe
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Answer queries about data
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Ensure data integrity
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Allow modification of data
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Control access to data
Data and Information
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Complex question
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For our purposes:
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Data: an elemental unit (a number, a word) that
requires interpretation to be meaningful
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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
Why a database?
●
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Consider some of the things a DBMS is
supposed to do
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Persistence
–
Answers to queries
–
Modification
Why can't we do it all with information?
–
Well we can, sort of .....
The Bank of Springfield
●
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Computerized, but everybody's account
information is stored in a word processing
document.
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e.g. '
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Account 124 # owned by # Montgomery Burns # has a balance of #$1211943.07'
Account 123 # owned by # Homer Simpson # has a balance of #$321.17
Suppose it meets all of the basic criteria of a
DBMS, so what's not so great about the BoS
system?
Databases Pros and Cons
●
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Taking a data perspective has huge advantages:
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Economy
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Speed
–
Scalability
But, there are also some disadvantages:
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Interpretation must be supplied
–
Getting answers to real questions is not so easy
Database Systems
●
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Evolution driven by the structure of the data
relationships:
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Hierarchical (tree structure)
–
Network
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Relational (table structure)
Most modern databases are relational because it
provides good balance between data abstraction
and performance
DBMS Life Cycle
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Planning – What is the goal? What
constraints exist?
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Analysis – Audit user requirements
●
Systems Design
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Implementation
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Maintenance