1. Chapter 1
Database Concepts

2. Introduction
Good decisions require good information derived from raw facts
Data is managed most efficiently when stored in a database
Databases evolved from computer file systems
Understanding file system characteristics is important

3. Why Databases?
Databases solve many of the problems encountered in data management
– Used in almost all modern settings involving data management:
• Business
• Research
• Administration
• Important to understand how databases work and interact with other applications

4. Why Study Databases? Databases have incredible value to businesses.
Very important technology for supporting operations.
Vastly superior to file processing systems
Businesses cannot survive without quality data about their
internal operations and
external environment.

5. Data vs. Information Data are raw facts
Information is the result of processing raw data to reveal meaning
Information requires context to reveal meaning
Raw data must be formatted for storage, processing, and presentation
Data are the foundation of information, which is the bedrock of knowledge

6. Data vs. Information Data: building blocks of information
Information produced by processing data
Information used to reveal meaning in data
Accurate, relevant, timely information is the key to good decision making • Good decision making is the key to organizational survival 

7. Foundation Data Concepts
Abstract Concepts
Entity – person, place, object or event – stored as a record or a table row
Attribute – characteristic of an entity – stored as field or table column

8. Foundation Data Concepts
Large
Database Concepts
Database – a collection of related tables
Tables – a collection of related records – collection of related entities
Record – collection of fields (table row) –represents an entity
Field – collection of characters (table column) – represents an attribute
Character – single alphabetic, numeric or other symbol
Small

9. Fields Characters “B R E I M E R” form a field
A field is an attribute of an entity
Last Name
Breimer

10. Records A bunch of fields form a record A record is an entity
First Name
Eric
Last Name
Breimer
Sex
Yes
Weight
263

11. Tables A bunch of records forms a table
A table is a group of related entities
First Name
Last Name
Sex
Age
Eric
Breimer M 30
Jeff
Albert 22
Jackie
Pizzo F 21

12. Databases A bunch of tables form a database
Databases
A bunch of tables form a database
A database can represent a single business or an entire market
Order Table
Customer Table
Product Table

13. Databases But, databases are not just a bunch of tables
But, databases are not just a bunch of tables
A database also includes relationships between the different tables
Orders
OID
CID
PID
Quantity
001
508
199
500,000
002
201 2
003
510 1
Customers
CID
FName
LName
Address
508
Eric
Breimer
...
509
Andrew
Zych
510
Greg
Smith
Products
PID
Description
Cost
199
Viagra
$45.99
200
Tooth Paste
$2.58
201
Hair Gel
$5.99

14. Relationships & Queries in Databases
Chapter 1
Relationships & Queries in Databases

15. Types of Relationships
One to One
Examples?
Analysis Technique
Consider ThingA and ThingB
Can ThingA be related to more than one ThingB?
Can ThingB be related to more than one ThingA?
If the two answers are NO, then it is a one to one relationship.
ThingA
ThingB
Relationship
Man
Woman
Married

16. Types of Relationships
Faculty
Student
One to Many
Examples?
Analysis Technique
Consider ThingA and ThingB
Can ThingA be related to more than one ThingB?
Can ThingB be related to more than one ThingA?
If only one answer is yes, then you have a one to many relationship
Advises
Get Advisement

17. Types of Relationships
student takes course
Course
Student
Many to Many
Examples?
Analysis Technique
Consider ThingA and ThingB
Can ThingA be related to more than one ThingB?
Can ThingB be related to more than one ThingA?
If the answers are yes and yes, then the relationship is many to many.
course has a student

18. How to Model Relationships
Orders
OID
CID
PID
Quantity
001
508
199
500,000
002
201 2
003
510 1
Customers
CID
FName
LName
Address
508
Eric
Breimer
...
509
Andrew
Zych
510
Greg
Smith
Products
PID
Description
Cost
199
Viagra
$45.99
200
Tooth Paste
$2.58
201
Hair Gel
$5.99

19. Find the name and hire date of the manager working on the sales manual project

20. Traditional File Processing Sucks
Data is organized, stored, and processed in independent files of data records

21. Problems of File Processing
Data Redundancy –
duplicate data requires update to many files
Lack of Integration –
data stored in separate files hard to combine data
Data Dependence –
changing the file format requires changing the program…

22. Database Management Approach
Consolidates data records into one CENTRAL database that can be accessed by many different application programs.

25. Database Management Software (DBMS)
Definition:
Software that controls the creation, maintenance, and use of databases

26. DBMS Software Components
Database Definition
Language and graphical tools to define entities, relationships, integrity constraints, and authorization rights
Application Development
Graphical tools to develop menus, data entry forms, and reports

27. DBMS Software Components
Transaction Processing
Controls to prevent interference from simultaneous users and
Controls to recover lost data after a failure
Database Tuning
Tools to monitor and improve database performance

28. Database Interrogation
Definition:
Capability of a DBMS to report information from the database in response to end users’ requests
Query Language – allows easy, immediate access to ad hoc data requests
Report Generator - allows quick, easy specification of a report format for information users have requested

29. Natural Language vs. SQL Queries

30. Schemas Schema - A description of the database
Subschema – describes a subset of the database and which users have access to this subset

31. Data Definition Language
Language Used to describe Schemas and Subschemas
Describes relationships between different data
Provides a Logical view of the data

32. Data Dictionary Entry
A more detailed description of the data in a database
Specifies data types and ranges
Assists programmers in understanding the data

33. Physical vs. Logical
DBMS concentrate on Physical access to the underlying tables
Concurrency control
Query’s
Creating/deleting tables

34. Physical vs. Logical MIS systems are (Logically) interface with a DBMS
monthly reports
charts
automated inquiries

35. Application Development
Today, even non-technical staff can use tools to build little programs that use a database.
Database Management Systems have all kinds of tools to develop custom application programs and interfaces.
Example: The College’s MIS (Banner) is actually an application built on top of a Oracle Database.