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Database Processing
David Kroenke
Using MIS 3e
Chapter 5
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Copyright 2011 Pearson Education, Inc. Publishing as Prentice Hall 5-2
Businesses of every size organize data records into collections called databases. At oneextreme, small businesses use databases to keep track of customers; at the other extreme,
huge corporations such as Dell and Amazon.com use databases to support complex sales,
marketing, and operations activities. In between, we have businesses like FlexTime that use
databases as a crucial part of their operations, but they dont have a trained and experienced
staff to manage and support the databases. To obtain answers to the one-of-a-kind queries he
needs, Neil needs to be creative and adaptable in the way that he accesses and uses his
database.
This chapter discusses the why, what, and how of database processing. We begin by
describing the purpose of databases and then explain the important components of database
systems. We then overview the process of creating a database system and summarize your
role as a future user of such systems.
Users have a crucial role in the development of database applications. Specifically, the
structure and content of the database depends entirely on how users view their business
activity. To build the database, the developers will create a model of that view using a tool
called the entity-relationship model. You need to understand how to interpret such models,because the development team might ask you to validate the correctness of such a model
when building a system for your use. Finally, we describe the various database administration
tasks.
This chapter focuses on database technology. Here we consider the basic components of a
database and their functions. You will learn about the use of database reporting and data
mining in Chapter 9.
Chapter Preview
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Q1 What is the purpose of a database?Q2 What is a database?
Q3 What are the components of a database application system?
Q4 How do database applications make databases more useful?
Q5 How are data models used for database development?
Q6 How is a data model transformed into a database design?
Q7 What is the users role in the development of databases?
Q8 2020?
Study Questions
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Copyright 2011 Pearson Education, Inc. Publishing as Prentice Hall 5-4
Purpose: to keep track of things
If structure of a list is simple, i.e., one theme,
no need to use database technology (video)
What Is the Purpose of a
Database?
http://media.pearsoncmg.com/ph/bp/bp_akamai/kroenke/videos.php?title=Chapter%205-%20What%20is%20the%20purpose%20of%20a%20database?&clip=pandc/kroenke/Ch_05_1.flvhttp://media.pearsoncmg.com/ph/bp/bp_akamai/kroenke/videos.php?title=Chapter%205-%20What%20is%20the%20purpose%20of%20a%20database?&clip=pandc/kroenke/Ch_05_1.flv7/28/2019 DB Processing Ch05
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Form for Recording Multiple
Themes
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Lists of data involving a single theme can bestored in a spreadsheet.
Lists that involve data with multiple themesrequire a database.
General Rule
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Q1 What is the purpose of a database?
Q2 What is a database?
Q3 What are the components of a database application system?
Q4 How do database applications make databases more useful?
Q5 How are data models used for database development?
Q6 How is a data model transformed into a database design?
Q7 What is the users role in the development of databases?
Q8 2020?
Study Questions
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Copyright 2011 Pearson Education, Inc. Publishing as Prentice Hall 5-8
Database:A self-describing collection of integrated
records
In databases, bytes are grouped intocolumns, such as Student Numberand
Student Name. Columns are also called
fields. Columns or fields, in turn, are
grouped into rows, which are also calledrecords.
Database
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Characters, Fields, and Records
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Hierarchy of Data Elements
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Metadata Describes Structure of
Database
Components of a Database
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What Are Relationships Among
Rows?
First row of the Email Table is
related to Andrea Baker in
Student Table
Last row in Office_Visit Tablerelated to Adam Verberra in
Student Table
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Key A column or group of columns that identifies a unique row in
a table.
Student Numberis the key of the Studenttable. Given a
value ofStudent Number, you can determine one and only
one row in Student. Only one student has the number 1325.
Every table must have a key.
Sometimes more than one column is needed to form a
unique identifier. In a table called City, for example, the key
would consist of combination of columns (City, State).
Email_Num is the key of Email Table.
VisitID is the key of Office_Visit Table.
Relationship Special Terms
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Foreign keys These are keys of a different (foreign) table
than the table in which they reside.
Relational databases Relationships among tables are created by
using foreign keys.
Relation
Formal name for a table
Relationship Special Terms
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Database: A database is a
self-describing
collection of
integrated
records.
Metadata
Data that
describe data
Metadata
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Q1 What is the purpose of a database?
Q2 What is a database?
Q3 What are the components of a database
application system?Q4 How do database applications make databases more useful?
Q5 How are data models used for database development?
Q6 How is a data model transformed into a database design?
Q7 What is the users role in the development of databases?
Q8 2020?
Study Questions
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Copyright 2011 Pearson Education, Inc. Publishing as Prentice Hall 5-17
Applications make database data more accessible and useful.
Users employ a database application that consists offorms,
formatted reports, queries, and application programs.
Database management system (DBMS) processes database
tables for applications.
Components of a Database
Application System
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What Is a Database Management
System (DBMS)?
DBMS A program (software) used to create, process, and administer
a database
Companies license DBMS products from vendors:
IBM, Microsoft, Oracle, and others
Popular DBMS products are:
DB2 from IBM
Access and SQL Server from Microsoft
Oracle from the Oracle Corporation
MySQLan open-source DBMS product that is license-freefor most applications
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Database developers use the DBMS to create and modify tables,relationships, and other structures in the database.
Below, the developer has added a new column called
Response?. This new column has data type Yes/No.
Creating the Database and Its
Structures
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DBMS operations Read, insert, modify, delete data
Applications call DBMS in different ways
From a form, when the user enters new orchanged data, a computer program behind the
form calls the DBMS to make the necessary
database changes.
From an application program, the program calls
the DBMS directly to make the change.
Processing the Database
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SQLsee-quell International standard language for creating
databases and database structures, and processing
databases
All five of the most popular DBMS products acceptand process SQL.
Following SQL statement inserts a new row into the
Student table:
INSERT INTO Student([Student Number], [Student Name], HW1, HW2, MidTerm)
VALUES
(1000, Franklin, Benjamin, 90, 95, 100);
Structured Query Language (SQL)
http://en.wikipedia.org/wiki/SQLhttp://en.wikipedia.org/wiki/SQL7/28/2019 DB Processing Ch05
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DBMS provides tools to assist in administration of thedatabase.
Used to set up a security system involving user
accounts, passwords, permissions, and limits for
processing the database Backing up database data, adding structures to
improve performance of database applications,
removing data no longer wanted or needed, and
similar tasks
Most organizations dedicate one or more employees
to the role of database administration.
Administering the Database
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Major Responsibilities of
Database Administration
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Q1 What is the purpose of a database?
Q2 What is a database?
Q3 What are the components of a database application system?
Q4 How do database applications makedatabases more useful?
Q5 How are data models used for database development?
Q6 How is a data model transformed into a database design?
Q7 What is the users role in the development of databases?
Q8 2020?
Study Questions
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Database Applications at
FlexTime
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What Are Forms, Reports, and
Queries?
Reports show data in a
structured context.
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What Are Forms, Reports, and
Queries?
Sample queryform used
to enter
phrase for
search
Sample query results of query operation
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Forms, reports, and queries work well for standardfunctions. However, most applications have unique
requirements that a simple form, report, or query
cannot meet.
Application programs process logic that is specific toa given business need.
Application programs serve as an intermediary
between the Web server and database.
Responds to events, such as when a user pressesa submit button; also reads, inserts, modifies, and
deletes database data
Why Are Database Application
Programs Needed?
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Four Database Application
Programs Running on a Web
Server Computer
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Lost-update problem Process A reads a customer record from a file containing account
information, including the customers account balance and phone
number.
Process B now reads the same record from the same file so it has
its own copy. Process A changes the account balance in its copy of the customer
record and writes the record back to the file.
Process Bwhich still has the original stale value for the account
balance in its copy of the customer recordupdates the customers
phone number and writes the customer record back to the file.
Process B has now written its stale account balance value to the file,
causing the changes made by process A to be lost.(Source: http://en.wikipedia.org/wiki/File_locking)
Multi-User Processing Problem
http://dba.fyicenter.com/Interview-Questions/RDBMS-FUNDAMENTALS/RDBMS_FUNDAMENTALS_Lost_Update_Problem.htmlhttp://dba.fyicenter.com/Interview-Questions/RDBMS-FUNDAMENTALS/RDBMS_FUNDAMENTALS_Lost_Update_Problem.htmlhttp://dba.fyicenter.com/Interview-Questions/RDBMS-FUNDAMENTALS/RDBMS_FUNDAMENTALS_Lost_Update_Problem.htmlhttp://dba.fyicenter.com/Interview-Questions/RDBMS-FUNDAMENTALS/RDBMS_FUNDAMENTALS_Lost_Update_Problem.html7/28/2019 DB Processing Ch05
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Enterprise DBMS Process large organizational and workgroup databases
Support many, possibly thousands, of users and many different
database applications
Support 24/7 operations and can manage databases that span
dozens of different magnetic disks with hundreds of gigabytes or
more of data
IBMs DB2, Microsofts SQL Server, and Oracles Oracle are
examples of enterprise DBMS products.
Personal DBMS
Designed for smaller, simpler database applications
Used for personal or small workgroup applications that
involve fewer than 100 users (normally fewer than 15), single
user
Enterprise DBMS vs. Personal
DBMS
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Access: A DBMS and an
Application Development Product
Before building a database, developers construct a logicalrepresentation of database data called a data model to describe the
data and relationships to be stored in database.
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Q1 What is the purpose of a database?
Q2 What is a database?
Q3 What are the components of a database application system?
Q4 How do database applications make databases more useful?
Q5 How are data models used for database
development?
Q6 How is a data model transformed into a database design?
Q7 What is the users role in the development of databases?
Q8 2020?
Study Questions
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Database Development Process
(video link needed)
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Entity-relationship (E-R) data model A tool for constructing data models
Developers use it to describe the content of a data
model by defining entities that will be stored in
database and relationships among those entities
Unified Modeling Language (UML), less popular,
tool for data modeling
What Is the Entity-Relationship
Data Model?
http://en.wikipedia.org/wiki/Entity-relationship_modelhttp://en.wikipedia.org/wiki/Unified_Modeling_Languagehttp://en.wikipedia.org/wiki/Unified_Modeling_Languagehttp://en.wikipedia.org/wiki/Unified_Modeling_Languagehttp://en.wikipedia.org/wiki/Entity-relationship_modelhttp://en.wikipedia.org/wiki/Entity-relationship_modelhttp://en.wikipedia.org/wiki/Entity-relationship_modelhttp://en.wikipedia.org/wiki/Entity-relationship_modelhttp://en.wikipedia.org/wiki/Entity-relationship_model7/28/2019 DB Processing Ch05
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Some thing that the users want to track Examples of entities:
Order, Customer, Salesperson, and Item. Some entities represent a
physical object, such as Item orSalesperson; others represent a
logical construct or transaction, such as OrderorContract.
Entity names are always singular. Attributes
Describe characteristics of an entity.
Examples: order attributes are OrderNumber, OrderDate, SubTotal,
Tax, Total, and so forth.
Identifier An attribute (or group of attributes) whose value is associated with
one and only one entity instance.
Entities
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Student Data Model Entities
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Entities with Relationships
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Sample Relationship (Version 1)
Crows
Feet
1:N N:M
N:M = many-to-many
relationships
One adviser can have manystudents and one student can
have many advisers.
1:N = many-to-many
relationships
One department can havemany advisers, but an adviser
has at most one department.
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Sample Relationships (Version 2)
Advisers may advise in more than one department, but a
student may have only one adviser, representing a policy that
students may not have multiple majors.
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Crows-Foot Diagram Version
Maximum cardinalitymaximum number of entities that can beinvolved in a relationship. Vertical bar on a line means that at least one
entity of that type is required.
Minimum cardinalityminimum number of entities that can be involved
in a relationship. Small oval means that the entity is optional; therelationship need not have an entity of that type.
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Q1 What is the purpose of a database?
Q2 What is a database?
Q3 What are the components of a database application system?
Q4 How do database applications make databases more useful?
Q5 How are data models used for database development?
Q6 How is a data model transformed into a
database design?
Q7 What is the users role in the development of databases?
Q8 2020?
Study Questions
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Database design is the process of converting a datamodel into tables, relationships, and data
constraints.
Database design team transforms entities into tables
and expresses relationships by defining foreign keys. Two important database design concepts:
normalization and the representation of two kinds
of relationships.
Normalization is a foundation of database design. Representation of relationships will help you
understand important design considerations.
Database Design
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Normalization
Normalization is the process of converting a poorly structured table intotwo or more well-structured tables. Problem with these tables, have two
independent themes: employees and departments.
http://dba.fyicenter.com/Interview-Questions/Data-Warehousing/What_is_Normalization_First_Normal_Form_Second.htmlhttp://dba.fyicenter.com/Interview-Questions/Data-Warehousing/What_is_Normalization_First_Normal_Form_Second.html7/28/2019 DB Processing Ch05
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In previous figure, some rows show Dept. 100 is Accounting andFinance and others show Dept. 100 is Accounting. Which one
is correct?
A table with data integrity problems will produce incorrect results
and inconsistent information.
Data integrity problems happen when data are duplicated.
Users will lose confidence in the information, and system will
develop a poor reputation. Information systems with poor
reputations become serious burdens to the organizations that
use them.
Data Integrity Problems
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Normalizing for Data Integrity
Normalized tables eliminate data duplication,but they can be slower to process.
General goal ofnormalization is to construct
tables such that every table has a single topic
or theme.
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The way to correct the problem is to split the table into twotables, each with its own theme.
Normalizing for Data Integrity
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Database practitioners classify tables into variousnormal forms according to the kinds of problems they
have.
Transforming a table into a normal form to remove
duplicated data and other problems is callednormalizing the table.
Normalization is just one criterion for evaluating
database designs. Normalized designs can be slower
to process, database designers sometimes choose to
accept nonnormalized tables. The best design
depends on the users processing requirements.
Summary of Normalization
http://en.wikipedia.org/wiki/Normal_formshttp://en.wikipedia.org/wiki/Database_normalizationhttp://en.wikipedia.org/wiki/Database_normalizationhttp://en.wikipedia.org/wiki/Normal_forms7/28/2019 DB Processing Ch05
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Representing Relationships
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Representing
a 1:N
Relationship
R ti N M
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Representing an N:M
Relationship
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Q1 What is the purpose of a database?
Q2 What is a database?
Q3 What are the components of a database application system?
Q4 How do database applications make databases more useful?
Q5 How are data models used for database development?
Q6 How is a data model transformed into a database design?
Q7 What is the users role in the
development of databases?Q8 2020?
Study Questions
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Users are the final judges of: What data the database should contain,
How tables should be related.
Users review data model to be sure it accurately
reflects users view of the business.
Mistakes will come back to haunt you.
Easiest time to change database structure is during
data modeling stage. Changing a relationship from
one-to-many to many-to-many in a data model issimply a matter of changing the 1:N notation to N:M.
User review o f the data model is crucial .
Users Role
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Q1 What is the purpose of a database?
Q2 What is a database?
Q3 What are the components of a database application system?
Q4 How do database applications make databases more useful?
Q5 How are data models used for database development?
Q6 How is a data model transformed into a database design?
Q7 What is the users role in the development of databases?
Q8 2020?
Study Questions
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Acxiom obtain data from public and private sources and storeand process it in sophisticated ways.
Use your grocery store club card, that data is sold to a data
aggregator. Credit card data, credit data, public tax records,
insurance records, product warrantee card data, voter
registration data, and hundreds of other types of data are sold toaggregators.
Using a combination of phone number, address, email address,
name, and other partially identifying data, such companies can
integrate that disparate data into an integrated, coherent whole
to form detailed descriptions about companies, communities, zipcodes, households, and individuals.
Data Aggregators
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Laws that limit the data that federal and othergovernmental agencies can acquire and store.
Some legal safeguards on data maintained by credit
bureaus and medical facilities.
No such laws that limit data storage by mostcompanies (nor are there laws that prohibit
governmental agencies from buying results from
companies like Acxiom.
Data Aggregators
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Absent any public outcry for legislation to limit suchactivity, aggregator data storage will continue to grow
exponentially and companies will have even more
data about you, the state of your health, your wealth,
your purchase habits, your family, your travel, your
driving record, and, well, anything you do.
Query, reporting, and data mining technology will
improve and Moores law will make computer
operations that are too slow to be practical today,
feasible tomorrow.
The picture of you will become more and more
detailed.
How Will this Change by 2020?
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Data could be stolen and used for criminalactivity against you.
Data might not be accurate.
No organization is required by law to tell you
the data that it stores about you and what it
does with it.
Why Do You Care?
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You enroll in a healthy eaters medicalinsurance program, similar to safe drivers
auto insurance. Your premiums are lower
because you eat well, except that the
insurance company notes from last monthsdata that you bought four large packages of
Cheetos, and your health insurance premium
is increased, automatically. You have no idea
why.
What If
Ethics G ide Nobod Said I
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Kelly was employed maintaining servers andbacking up database.
Made copy of database to practice with Queried SQL server metadata Discovered tables with order data, customers,
salespeople Uncovered anomaliesone entry clerk gave
discounts to a buyer that no other clerks gavediscounts to
Mentioned it to a clerk Was terminated for accessing database
Ethics Guide: Nobody Said I
Shouldnt
Ethics Guide: Nobody Said I
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Where did Kelly go wrong? Was it illegal, unethical, or okay for Kelly to
copy the database and take it home?
How should Kelly have handled his discovery
of the anomaly better?
Does Kelly have any legal recourse over
being fired?
How can a business protect its databasesfrom unauthorized use?
Ethics Guide: Nobody Said I
Shouldnt
Guide: No Thanks Ill Use a
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Databases take time to build. Complicated to operate
May require use of multiple applications
Need IS people to create it and keep itrunning
Will share data that you may not want to
expose
Spreadsheets may be a better option in somecases.
Guide: No, Thanks, Ill Use a
Spreadsheet
Guide: Immanuel Kant Data
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What we perceive as reality is based on ourperceptive apparatus. That which we perceive
he called phenomena.
Our perceptions, such as of light and sound,
are processed by our brains and mademeaningful.
But we do not and cannot know whether the
images we create from the perceptions haveanything to do with what might or might not
really be.
Guide: Immanuel Kant, Data
Modeler
Guide: Immanuel Kant Data
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Noumenal worldrefers to the essence of things inthemselvesto whatever it is out there that gives rise
to our perceptions and images.
Phenomenal world refers to what we humans
perceive and construct.
Easy to confuse the noumenal world with the
phenomenal world, because we share the
phenomenal world with other humans.
Shared mutual view does not mean that the mutual
view describes the real world.
Guide: Immanuel Kant, Data
Modeler
Guide: Immanuel Kant Data
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Nothing that humans can do represents the real, noumenalworld. A data model, therefore, is a model of a humans
model of what appears to be out there.
Data models do not model the real world. A data model is
simply a model of what the data modeler perceives.
Must ask the question, How well does the data model fitthe mental models of the people who are going to use the
system.
Only valid point is whether it reflects how users view their
world. Will it enable the users to do their jobs?
Guide: Immanuel Kant, Data
Modeler
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Q1 What is the purpose of a database?
Q2 What is a database?
Q3 What are the components of a database application system?
Q4 How do database applications make databases more useful?
Q5 How are data models used for database development?
Q6 How is a data model transformed into a database design?
Q7 What is the users role in the development of databases?
Q8 2020?
Active Review
C St d 5 B h ki
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PC-Magazine test compared five DBMS products:
DB2 (from IBM)
MySQL (a free, open source DBMS)
Oracle (from Oracle Corporation)
SQL Server (from Microsoft)
ASE (from Sybase Corporation)
SQL Servers performance was worst performer.
Microsoft complained, so PC-Magazine reran the test using Microsoft-
supporting software. SQL server performed best this time. However, the second test compares apples and oranges.
Do benchmarks really mean anything? How should customers use
benchmarks?
Case Study 5: Benchmarking,
Bench Marketing, or Bench
Baloney
7/28/2019 DB Processing Ch05
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permission of the publisher. Printed in the United States of America.
Copyright 2011 Pearson Education, Inc.Publishing as Prentice Hall
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