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Chapter 5
Database Processing
“No, Drew, You Don’t Know Anything About Creating
Queries."
• AllRoad Parts operational database used to determine which parts to
consider for 3D printing.
• If Addison and Drew depend on Lucas (or IT dept) to produce reports,
they will (a) wait a long time and (b) probably not get what they want.
• Once they get data, Addison create queries and reports without help
from Lucas.
• Relying on own skills gives more freedom and better results.
• Relational database technology not appropriate for 3D parts files or
graphics used for query-by-graphics. MongoDB a better choice.
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Study Questions
Q1: What is the purpose of a database?
Q2: What is a database?
Q3: What is a database management 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: 2024?
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Q1: What Is the Purpose of a Database?
• Organize and keep track of things
• Keep track of multiple themes
• General rule:
 Single theme - store in a spreadsheet
 Multiple themes - use a database
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A List of Student Grades Presented in a Spreadsheet
– Single Theme
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Student Data Form With Multiple Themes
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Q2: What Is a Database?
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Hierarchy of Data Elements
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Components of a Database
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Example of
Relationships
Among Rows
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Sample Metadata (in Access)
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Ethics Guide: Querying Inequality?
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MaryAnn has a data mart.
Business professional majored in HR, now "expert" in SQL.
Uses SQL to do her job faster and better.
What are your personal, professional, social responsibilities?
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Ethics Guide: Querying Inequality? (cont’d)
• You can query databases to learn all sorts of patterns and trends.
– Be sure what answers you want before starting query.
• How strongly do you feel about social and personal responsibility,
considering your needs and those of your family?
• How important is social responsibility posture of an employer to
you? Is that something you want to add to your criteria for finding
a job?
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Q3: What Is a Database Management System
(DBMS)?
• Program used to create, process, and administer a
database.
• Licensed from vendors such as IBM, Microsoft, Oracle, and
others.
• DB2 from IBM, Access and SQL Server from Microsoft,
Oracle Database from Oracle Corporation.
• MySQL - open source, license-free for most applications.
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Processing the Database
Four DBMS operations
1. Read
2. Insert
3. Modify
4. Delete data
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Processing the Database
• Structured Query Language - SQL (see-quell)
– International standard
– Used by most popular DBMS
INSERT INTO Student
([Student Number], [Student Name], HW1, HW2, MidTerm)
VALUES (1000, ‘Franklin, Benjamin’, 90, 95, 100)
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Administering the Database
• Used to set up a security system involving user accounts,
passwords, permissions, and limits for processing.
• Permissions can be limited in very specific ways.
• Backing up database data, adding structures to improve
performance of database applications, removing unwanted
data.
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Summary of Database Administration Tasks
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Summary of Database Administration Tasks (cont'd)
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Elements of Database Applications
Forms
View data;, insert new, update existing, and delete
existing data
Reports
Structured presentation of data using sorting,
grouping, filtering, and other operations
Queries
Search based upon data values provided by the user
Application Programs
Provide security, data consistency, and special
purpose processing, e.g., handle out-of-stock
situations
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Using MIS InClass 5: How Much Is a Database Worth?
• Data has resale value.
• Data on everything customers do.
• Use to target customers for offerings they care about, and
avoid those they don’t.
• Costly and difficult to replace data collected over many
years.
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Q4: How Do Database Applications Make Databases
More Useful?
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Example of a Student Report
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Query Example
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Browser Forms, Reports, Queries, and Applications
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Account Creation Browser Form
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Browser
Report
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Multi-User Processing Problem
1. Process A reads
customer record
from file containing
customer’s account
balance.
1
5. Process B writes
stale account
balance value to file,
causing changes
made by Process A
to be lost.
3. Process A updates
account balance in
its copy of customer
record and writes
record to file.
2
3
2. Process B reads
same record from
same file now has
its own copy.
4
5
4. Process B has original
stale value for account
balance. Updates
customer’s phone number
and writes customer
record to file.
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Q5: How Are Data Models Used for Database
Development?
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Components of the Entity-Relationship Data Model
Entities
• Something users want to track
• Order, customer, salesperson, item,
volunteer, donation
Attributes
• Describe characteristics of an entity
• OrderNumber, CustomerNumber,
VolunteerName, PhoneNumber
Identifier
• Uniquely identifies one entity instance
from other instances
• Student_ID_Number
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Student Data Model Entities
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Example of Department, Adviser, and Student Entities
and Relationships (cont'd)
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Sample of Relationships―Version 1
Crow’s
Feet
1:N
One department can have
many advisers, but an
adviser may be in only one
department
N:M
An Adviser ma have many
students, and one student
may many advisers
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Sample of Relationships─Version 2
“Crow’s
Foot”
N:M
A department has many
advisors, and an advisor
may advise for more
than one department
1:N
A student has only one
advisor, but an adviser
may advise many
students
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Crow’s-Foot Diagram Version
Maximum cardinality─maximum number of entities involved in a
relationship. Vertical bar on a line means that at least one entity
is required.
Minimum cardinality—minimum number of entities in a
relationship. Small oval means entity is optional; relationship
need not have an entity of that type.
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Q6: How Is a Data Model Transformed into a
Database Design?
• Normalization
– Converting poorly structured tables into two or more wellstructured tables.
• Goal
– Construct tables with data about a single theme or entity.
• Purpose
– To minimize data integrity problems.
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Data Integrity Problems
• Data integrity problems produce incorrect and inconsistent
information, users lose confidence in information, and the
system gets a poor reputation.
• Can only occur if data are duplicated.
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Poorly Designed Employee Table Causes Data
Integrity Problem
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Two Normalized Tables
Single
Themes
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Summary of Normalization
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Representing 1:N Relationships
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Representing an N:M Relationship: Strategy for
Foreign Keys
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Q7: What Is the Users’ Role in the Development of
Databases?
• Users are the final judges of:
– What data database should contain.
– How tables should be related.
• Users review data model to ensure it accurately reflects
users’ view of the business.
 Mistakes will come back to haunt them.
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Q8: 2024?
• Volume of database data will continue to grow, probably
exponentially.
• Cheap, unlimited storage space and greater processing
speeds do in relational databases.
• Relational model is not needed, not natural fit with business
documents.
• Store new types of data such as images, audios, and videos.
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Q8: 2024? (cont'd)
• More reliance on open source community.
• Many NoSQL databases will exist.
• New opportunities and career paths will develop around
NoSQL databases.
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Q8: 2024? (cont'd)
NoSQL DBMS (Not Relational DBMS)
Supports very high transaction rates.
Relatively simple data structures.
Replicated on many servers in the cloud.
• Examples
Dynamo (Amazon)
Bigtable (Google)
Cassandra (Facebook)
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Q8: 2024? (cont'd)
• Will NoSQL Replace Relational DBMS Products?
– Conversion very expensive and disruptive.
– Very technical, limited to those with a deep background in
computer science.
– Requires years of training to use.
– Organization may choose NoSQL products for specialized
applications.
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Guide: No, Thanks, I’ll Use a Spreadsheet
Construct a data model and have users validate it.
• Design database.
• Implement database, and fill it with data.
• Design, build, and test database applications.
• Write procedures.
• Train users.
• Maintain system.
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Guide: No, Thanks, I’ll Use a Spreadsheet (cont'd)
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Databases take time to build.
Complicated to operate.
Need IS people to create and keep them running.
Salesman doesn’t want to share data.
Spreadsheets sometimes better option, especially if data
needs are simple.
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Guide: Immanuel Kant, Data Modeler
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Perception of reality is based on our perceptive apparatus.
Brain processes perceptions into something meaningful.
Human’s model what appears to be.
Users must determine if a data model fits their perception of
reality.
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Active Review
Q1: What is the purpose of a database?
Q2: What is a database?
Q3: What is a database management 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: 2024?
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Case Study 5: Fail Away with Dynamo, Bigtable, and
Cassandra
• Current relational DBMS products not designed for large,
multi-server systems.
• NoSQL databases – Dynamo, Bigtable, Cassandra.
• Amazon: Dynamo.
• Google: Bigtable processes petabytes of data on hundreds
of thousands of servers.
• Both created to be elastic.
• Cassandra used by Facebook, Twitter, Digg, Reddit.
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