Lec11chap10f04

Lecture 11 / Chapter 10 COSC1300/ITSC 1401/BCIS 1405 11/8/2004
F.Farahmand 1 / 12 File: lec11chap10f04.doc
General Items:
• Lab? Ok?
• Web page updated
• Need to come to class
• Have a quiz / no books / use notes -> What is the big idea
•
Reading Materials:
•
Miscellaneous:

Data and Information
- Data is a collection of unprocessed facts, figures, sound, images, video,
and symbols
o => So what is “unprocessed” about all these?
o When data is “processed” we have information
o Processing depends on what you want to do with it!
emailing an image
taking the “red eye” out
looking at a picture
- Everyday we receive hundreds of different data types and we process
them (hopefully!)
o How do we receive the data?
o How do we process the data?
o What do we do with the processed data?
Processor
Data
Information
Database

- We actually do much more than just processing the data:
o Check its accuracy
Keep it Korekt!
o Organize it
Don’t get confused! %$#$@&@^*$I@&@
o Keep it current
Update what you know! WHAT IS IT TODAY?
o Keep it reliable and accessible
Don’t forget! HUH???
o What else?
o
- Other examples of database?
o Driver license
o Social security office
Database Software
-Also called database management system (DBMS)
-Used to create, change, retrieve, delete, data and information
-Organizes and manages the data
-Examples: Access
-A computer must also check for data accuracy and correctness
o Checking the data integrity
Wrong price in the cash register!
o TITO or GIGO (Garbage-in-garbage-out)
-How do database software work?
o Organize the data in layers
So how is your “database” working today?

o The smallest unit of data is called a field (made of
characters and numbers, etc.)
Each field has a size
Each data has a type
-Text, number, date, memo, object, etc.
o A group of fields is called a record
o Each record is uniquely identified by the key field (primary
key)
-What is our primary key in this class?
Database Software and maintaining the data
- Procedures that keep the data current
o Adding, Changing, Deleting records
o Data validation
Setting some rules for data values (My son was born before
he was admitted in the hospital!)
• Alphabetic and numeric check (My Phone # is WER32
• Range check (I was born on Sep. 34, 1287)
• Consistency check (I live in Dallas; zip code = 600023)
Social Sec
Phone
Address
Name
Number Character
Student RECORD
FIELD
TYPE

So how is the data processed?
Two ways: File processing and database processing
File processing:
- A dedicated file for each application/department/group
o Each teacher has her/his own student record!
- Disadvantages: Isolated data, lots of redundancies, difficult to update,
unable to share information
- Advantages: Shorter and less complex databases
Database processing:
- Data can be shared between different users
o Your social security number
- Disadvantages: Complex and large, more vulnerable
- Advantage: Higher integrity, Less redundancy
So which is better? Which one works for you?
Should the instructors have access to all your grades
in other classes?

Managing the data
How to keep and access what we want, when we want it: creating, deleting,
retrieving, etc.
- Database systems differ in many ways:
o Capacity, platform, flexibility
- Yet, database systems have many common tools
o Query: request for a specific data from the database
o There are 4 ways we can perform a query
Query-by-language: Need to know the field and proper
vocabularies – know the query language!
Query-by-example: Match a criteria
Forms: Allows electronic data entry
Report generators: Use it to retrieve and display data
o Security
Securing data from unauthorized personnel
Using access privileges (read-only)
o Backup and Recovery
Administrating the database
Managing and coordinating all database activities (analysts and
administrators)
Providing database design guidelines
o Make sure the data and information are valuable, including
Accurate: Correctness and integrity
Verifiable
Organized
How do you do you Query?

Data based management system (DBMS)
A software that allows you to create, manage, access a database
Performs many functionalities including:
o Data dictionary (Repository) – keeps track of who is accessing the
data, validation check, setting default values, etc.
o File retrieval and maintenance – performing a Query using
different methods
Voice, programming language, etc.
o Data security – ensuring that only authorized personnel can access
the right data
Access privilege: actions that a specific user can perform
Read-only privilege: only reading is allowed!
o Backup and recovery – protecting the database in case of any HW /
SW failure
Copy the entire database
Maintain a log
• Record all activities performed on the DB
Maintaining after image, before-image

Database model
- Rules and standards that define how the database is organized
- Popular data models: Relational, object-oriented, multidimensional
- Relational Databases:
o Using tables consisting of rows and columns to store the data
o A relationship is a connection within the data between tables
o Example: Access software
- Object-oriented Databases:
o Storing data in objects
o An object contains both data and activities that read or process the
data (data + printing instructions, different formulas, etc.)
o Provide faster access and can store more types of data
o Examples:
Multimedia database: Storing audio, video, images
(unstructured data)
A groupware database: Storing memos, documents, reports
Web database: Containing links to e-forms
- Object-relational Databases: Mixing different features of object-oriented
and relational databases
- Multidimensional Databases:
o Storing data in dimensions
How many dimensions do relational database have?
A retailing business may have four dimensions: customers,
regions, products, and time
What about Brookhaven College?
o Provides a much faster data consolidation

WEB Database
- One of the largest databases
- Have you done a search lately?! How can it be so fast?
- Web database resides on a database
- There are many searching techniques – the goal is fast access
o Web crawling
o Common Gateway Interface
-
Browser:
Sending
the search
text The
server
performs
the searchBrowser:
Receiving
the search
results

- Information system types
- A set of HW and SW, data, people, and procedures to produce
information
- Categories (5)
o Office information systems: communication among employees
o Transaction processing systems: used for money transactions
between users and companies (ATM machine)
o Management information systems: organized information which
can help users to solve problems, track activities, etc.
o Decision support systems: provide information which help in
decision making process
o Expert systems: imitating human reasoning and decision making
One aspect of artificial intelligence: application of human
intelligence to computers
- Data warehouse: large database that stores, archives, and manages
different types of data
o It can consist of many different types of data
o Web framing: process of collecting data from the Internet
o Data mining: process of finding patters and relationships among
data

QUIZ
What is a Query?
Name two different data types.
Name two processing approaches.
What is a primary key?
What is data validation? Give an example.

Basic issues:
• Security?
• Privileges?
• Privacy?
National ID
School
Bank
Social Security
Airports
Classes
Library
Major
Address
Traffic violations
Library
Driver license
Trips
Exit/entry times
Accounts
Credit cards
Income
Job
Place of work
City/Police

Lec11chap10f04

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