Chapter 13 - Databases and Info. Management
Data and Information
What is data?
° A collection of raw unprocessed facts, figures, and
symbols
What is information?
° Data that is organized, meaningful, and useful
How are data and information
related?
° Computers process data into information
What is a database?
° Includes a collection of data
organized so you can access,
retrieve, and use the data
° Database software allows
you to
Create a computerized database
Add, change, and delete data
Sort and retrieve data from the database
Create forms and reports for the data in the database
° Database software also called a database management
system (DBMS)
What is data integrity?
° The degree to which data is correct
° When a database contains errors, it loses integrity
° Very important because computers and people use information
to make decisions and take actions
The Hierarchy of Data
What is a field?
° A
combination of one or more
characters
° The smallest unit of data a user accesses
° A field name uniquely identifies each field
What are characteristics of a
field?
° Data type
Specifies the kind of data a field can contain
Specifies how the field is used
° Field size
Defines the maximum number of characters a field can
contain
What is a record?
° A group of related fields
What is a data file?
° Also called a file
° A collection of related records stored on a disk
° Each record in the file contains the same fields
° Each field contains different data
Maintaining Data
What is file maintenance?
° Also called data maintenance
° The procedures that keep data current
How are records added?
° A clerk uses a Customer Maintenance program to add a
new record
° The clerk enters the data for each field of the record
° The clerk takes a photograph with a digital camera and
confirms the data is correct
° The clerk then adds the record to the database file
How are records changed?
° The clerk starts the Customer Maintenance program
° The clerk displays the customer record on the screen
° The clerk makes the corrections
° The clerk verifies the data and then clicks the Save
button to change the record in the Customer file
How is data deleted?
° The clerk starts the Customer Maintenance program
° The clerk displays the customer record on the screen
° The clerk confirms the correct customer record
displays
° The clerk clicks the Delete Record button
What is validation?
° The process of comparing data to a set of rules or
values to find out if the data is correct
° A validity check analyzes entered data to help ensure
that it is correct
° Validity
checks
are also
called
validation
rules
What are the types of validity
checks?
What
is an example of a completeness check?
° If you do not fill in a required field, an error
message usually displays stating which required fields you left blank
What is a check digit?
° A number(s) or character(s) that is appended to or
inserted into a primary key value
° Used to confirm the accuracy of a primary key value
° When the primary key is entered, the program applies
the check digit formula to determine if the primary key is valid
File Processing Versus Databases
What is a file processing system?
° Each department or area within an organization has its
own set of files
° Records in
one file often
do not relate
to the
records in
any other file
What are the weaknesses of a file
processing system?
What is the database approach?
° Many programs and users can share the data in the
database
° Secures the data so only authorized users can access
certain data items
What
are the strengths of the database approach?
How
do a database application and a file processing application differ in the way
they might store data?
Database Management Systems
What
is a database management system (DBMS)?
° Software that allows you to create, access, and manage
a database
° Available for many sizes and types of computers
What is a data dictionary?
° Also called a repository
° Contains data about each file in the database and each
field within those files
° Sometimes called metadata because it contains data
about data
What is a default value for a
field?
° A value that the DBMS initially displays in a field
° Data dictionary allows you to specify a default value
for a field
What is a query?
° A request for specific data from the database
° Four commonly used methods to access data
What is a query language?
° Consists of simple, English-like statements that allow
you to specify the data to display, print, or store
What is a query by example (QBE)?
° The program retrieves records that match criteria you
enter in the form fields
° Uses a graphical user interface
What is a form?
° Sometimes called a data entry form
° A window on the screen that provides areas for
entering or changing data in a database
What is an electronic form?
° Also called an
e-form
° A form that sends entered data across a network or the
Internet
° Typically uses a means to secure the data while it is
transported
What is a report generator?
° Also called a report writer
° Allows you to design a report on the screen, retrieve
data into the report design, and then display or print the report
° Usually allows you to format page numbers and dates;
titles and column headings; subtotals and totals; and fonts, font sizes, color,
and shading
What is data security?
° A DBMS
provides means
to make certain
only authorized users can access data at permitted times
° Most DBMSs allow you to
identify different levels of access privileges for each field in the database
How should you protect data stored
in a database?
° A DBMS provides a variety of techniques to restore a
database to a usable form in case it is damaged or destroyed
What is a log?
° A listing of activities that change the contents of
the database
° For every change the DBMS places three items in the
log
What is a recovery utility?
° Uses the logs and/or backups to restore a database
when it is damaged or destroyed
° Restores the database
using
rollback and
rollforward techniques
Relational,
Object-Oriented and Multidimensional Databases
What is a data model?
° Every database and DBMS is based on a specific data
model
° Consists of rules and standards that define how the
database organizes data
° Defines how users view the organization of the data
° Three popular data models in use today
Object-relational databases combine features of the
relational and object-oriented data models
Company on the Cutting Edge
° Oracle products are
used by 96 percent
of the Fortune 500
companies
° In 1977, Larry
Ellison co-founded
Oracle
° Now the worlds
leading supplier of
software for
e-business
° Its database product, also named Oracle, is the
worlds leading database software
Technology Trailblazer
E. F. Codd
° In 1970, he created the relational approach to
database management
° Codds model continues to serve as the de facto standard on
which large and small databases are structured
Relational,
Object-Oriented, and Multidimensional Databases
What is a relational database?
° Stores data in tables that consist of rows and columns
° Each row has a primary key and each column has a
unique name
° A relational database uses terms different from a file
processing environment
What is a relationship?
° A connection within the data
° Relationships stored as part of a relational database
° Normalization is a process designed to make sure the
data within the relations (tables) contains the least amount of duplication
What is relational algebra?
° Uses variables and operations to build new relations
° Used to manipulate and retrieve data
° Variables are the tables, rows, and columns of the
database
What is an example of a projection
operation?
° The operation extracts data from a column (field)
What is an example of a selection
operation?
° The operation extracts data from a row (record)
What is an example of a combined
projection and selection operation?
° The operation extracts data from a column (field)
What is an example of a join
operation?
° Combines the data from two or more tables using a
common column
What is Structured Query Language
(SQL)?
° A query language that allows you to manage, update,
and retrieve data
° Uses relational algebra
° Has special keywords and rules that you include in SQL
statements
What is an object-oriented database
(OODB)?
° Stores data in objects
° Advantages
Can store more types of data
Can access the data faster
What
are examples of applications appropriate for an OODB?
What is an example of a hypermedia
database?
° To display information about a particular artifact,
you enter its description in the Keywords text box
What is a multidimensional database
(MDDB)?
° Stores data in dimensions
° Can store more than two dimensions of data
° Sometimes known as a hypercube
Web Databases
What is a Web database?
° A database of information that can be accessed through
the Web
° A vast amount of information available through the Web
Company
on the Cutting Edge
° A free, national directory of U.S. residential
information
° Among the 50 most popular Internet sites
° Contains telephone number and
address
directories for
nearly 100-
million people,
12-million
businesses,
and 4-million
U.S. e-mail
addresses
Web Databases
How can you access a Web database?
Database Administration
What
is the role of the database analyst and administrator?
° Responsible for managing and coordinating all database
activities
° In small companies, one person often is both the
database analyst and administrator
What is the role of the employee as
a user?
° Employee should learn how to utilize the data in the
database
° Must take an active role in identifying new data for
the database
° Take part in designing
the database that will
help achieve
companys overall
goals
What are guidelines for developing
a database?
Qualities of Valuable Information
What
are the qualities of valuable information?
° Characteristics of information make it valuable
How do managers use information?
° Managers are responsible for coordinating the use of
resources
Resources include people, money, materials, and
information
° Perform four activities
What are the levels of users?
° The types of information you need often depend on your
employee level in the company
Technology Trailblazer
Larry Ellison
° Oracle chairman and
co-founder
° Uncanny ability to motivate his employees and partners
toward a common vision
° Co-founded Oracle in 1977
° Goal is to grow Oracle into the largest software
company in the world
Types of Information Systems
What is an information system?
° A set of hardware, software, data, people, and
procedures that work together to produce information
What are the five categories of
information systems?
What is an office information
system (OIS)?
° Increases employee productivity and assists with
communications among employees
° Often described as office automation
What
is a transaction processing system (TPS)?
° Captures and processes data from day-to-day business
activities
° Includes several business activities
Recording a business activity
Confirming an action or causing a response
Maintaining data, which involves adding new data,
changing existing data, or removing unwanted data
What are forms of transaction
processing systems?
° Initially referred to as data processing
° Intent of earliest TPSs was
to process faster, reduce clerical costs, and improve customer service
What
is a management information system (MIS)?
° Generates accurate, timely, and organized information
° Managers and other users can
Make decisions
Solve problems
Supervise activities
Track progress
° Often integrated with transaction processing systems
What are the three basic types of
information created by an MIS?
° Detailed report
Usually just lists transactions
What are the three basic types of
information created by an MIS?
° Summary report
Consolidates data, so you can review it quickly and
easily
Usually has totals, tables, or graphs
What are the three basic types of
information created by an MIS?
° Exception report
Identifies data outside of a normal condition
Conditions, called exception criteria, define the
normal activity or status range
What is a decision support system
(DSS)?
° Helps you analyze data
and make decisions
° A variety of DSSs exist
Some are company specific
Others are available to everyone on the Web
° Uses data from internal sources
From within a company
° Uses data from external sources
From outside a company
What is an executive information
system (EIS)?
° A special type of DSS
° Supports the strategic
information needs of executive management
° Presents information as charts and tables that show
trends, ratios, and
statistics
What is a data warehouse?
° A huge database system that stores and manages the
data required to analyze historical and current transactions
° The data
can come
from internal
or external
sources
What are terms associated with a
data warehouse?
What is an expert system?
° Captures and stores the knowledge of human experts
° Imitates human reasoning and decision making
° Two main components
° One part of a branch of computer science called
artificial intelligence (AI)
The application of human intelligence to computes
How does an expert system work?
What is an integrated information
system?
° It is often difficult to classify an information
system as belonging to only one of the five types of information systems
Summary of Databases and
Information Management
° Data and information
° The hierarchy of data
° Maintaining data
° File processing versus databases
° Database management systems
° Relational, object-oriented, and multidimensional
databases
° Web databases
° Database administration
° Qualities of valuable information
° Types of information systems
Chapter 13 Complete