2 - 3 page comprehensive assessment of the chapter-4
luckyzratanl
IST5500Chapter411.pptxInformation Systems For Business and Beyond
Chapter 4
Data and Databases
IST
5500
1
Objectives
Describe differences between data, info & knowledge
Define database & identify steps to create one
Describe role of a database management system
Describe characteristics of a data warehouse; and
Define data mining & describe its role in an organization
2
Data, Information & Knowledge
Data: raw bits & pieces of info
Quantitative or qualitative
Data alone not useful
Needs context to be information
Aggregate & analyze: knowledge
Knowledge used for decisions
Wisdom includes experience!
NOTE: We will not be discussing older, hierarchical databases during this class
Databases
Relational database most popular
Limit our discussion to them
Examples: MS Access, MySQL & Oracle
Data organized into one or more tables
Each table contains set of fields
A record is one instance of a set of fields
Tables related by one or more fields: primary key
Database Design
Needs, requirements & goals?
Define data requiring tracking
Determine tables needed
Specifically which fields
Data to which they will relate
Establish primary key (unique)
Normalize: avoid duplicates & achieve flexibility
Designing a Database
Example: a university wants to create an information system to track participation in student clubs
Goal to give insight into how university funds clubs
Track number of club members & club activeness
Must keep track of the clubs, members & events
Following tables needed:
Clubs: club name, club president, short description of club
Students: student name, e-mail, year of birth
Memberships: correlates students with clubs, any given student can join multiple clubs
Events: when clubs meet & attendance
Designing a Database continued
Primary key must be selected for each table to create a relationship
unique identifier for each record in a table
Designing a Database Table Details
Designing a Database Table Details cont.
Designing a Database continued
Normalization
Design database in a way that:
reduces duplication of data between tables
gives table as much flexibility as possible
Purpose of creating Memberships table separate from Students & Clubs tables
Makes it simple to change design without major modifications to existing structure
Data Types
Each field in a database table needs a data type
Text, Number, Yes/No, Date/Time, Currency, Object, etc.
Importance of properly defined data types
tells database what functions can be performed
proper amount of storage space is allocated for data
Data Types: Assigned by Fields
Text – generally under 256 characters
Numbers* – usually different types
Yes/No – decisions (*special type)
Date/Time – formats (*special type)
Currency – types (*special type)
Paragraphs - allows text over 256
Objects – images, music, etc.
Database Tables 1NF (1st normal form)
Database Demonstration
Time permitting: Microsoft Access
Structured Query Language (SQL)
Work with relational databases
Simple requests or complex tasks
Example creates list of number students in each club, listing club name & number of members:
SQL: What can it do?
Execute queries against a database
Retrieve data from a database
Insert, update & delete records
Create
new databases
new tables in a database
stored procedures (transactions)
views in a database
Set permissions on tables, procedures, and views
Other Types of Databases
Relational database model is most used today
Hierarchical database model
popular in the 1960s & 1970s
connected data together in hierarchy, allowing for parent/child relationships
Document-centric model
allowed for a more unstructured data storage by placing data into “documents” that could then be manipulated
NoSQL (“not only SQL”)
Arose from need to solve problem of large-scale databases spread over several servers or even across world
Can work with data in a looser way (no need for locks), allowing for a more unstructured environment, communicating changes to the data over time to all the servers that are part of the database
Database Management Systems
Software packages providing for:
Database creation
Reading/querying
Changing/updating
Add to or removing
Single user: MS Access & OpenOffice
Enterprise Databases
Multi-user
Networked
Metadata: Data about Data> Example
Enterprise Databases
Databases must be accessible to more than one person at a time
Relational enterprise database packages built to support two, ten, or even a million people
Relational databases have a scaling issue
Big Data
such massively large data sets that conventional database tools do not have the processing power to analyze them
understanding best tools & techniques to manage & analyze these large data sets is a problem that governments & businesses alike are trying to solve
Data Warehouse
Typically a separate database
Used analyze large amounts of data
Should be designed such that:
uses non-operational data
data is time-variant (time stamped)
data is standardized
data is standardized
Data Warehouse continued:
Data mining
Online Analytical processing (OLAP)
Purpose: building business intelligence
Data Warehouse continued:
Top-down DW
Data Warehouse Benefits
Process of developing data warehouse forces organization to better understand data it is currently collecting and, equally important, what data is not being collected
Provides centralized view of all data being collected across enterprise; provides means for determining data consistency
Once all data identified as consistent, an organization can generate one version of the truth. IMPORTANT when company wants to report consistent statistics about itself, such as revenue or number of employees
Snapshots of data can be taken over time, creating historical record of data, allowing for trend analysis
Provides tools to combine data, which can provide new information & analysis
Data Mining
Process of analyzing data to find previously unknown trends, patterns & associations to make better decisions
Accomplished thru automated means against extremely large data sets, e.i., data warehouse market basket analysis
Beer and diapers
Target pregnancy prediction
Privacy Concerns
Becoming easier than ever to take data from disparate sources and combine them to do new forms of analysis
Business Intelligence & Business Analytics
Business intelligence process that organizations use to take collected data & analyze hoping to obtain competitive advantage
Business analytics is use of internal company data to improve business processes & practices
Knowledge Management (KM)
All companies accumulate knowledge over course of their existence
Much knowledge is not written down; instead, stored inside heads of employees
KM, process of formalizing capture, indexing & storing of company’s knowledge to benefit from experiences & insights that company has captured during its existence
Maplewood Test Lab
Customer Data
Procedures
Privacy Concerns
Regarding databases:
Security controlled access
Access limited by login
We’ll discuss further in Chapter 12
Software QA: Data Owners
Evaluate SQA classification (i.e. criticality)
Develops controls to assure data integrity
Evaluates and dispositions data error notices
Assures appropriate disaster prevention & recovery
SQA: Disaster Recovery
Software/data owners include disaster recovery in requirements specs or SQA Plan
At a minimum, considers prioritization & recovery of important/critical software systems & data
Plans/procedures documented
Periodically tested
Evaluated when there are changes to the software, the data or the operating environment
Normally, software & data owners are the same person or organization, but they do not have to be
Group Discussion 1:
Your group has been asked to determine the requirements for designing a database for your Junior Baseball League. List the pieces of information that you need to acquire from stakeholders in order to minimize shortcomings and iterations during the preliminary design phase.
Form into groups of 4 or 5
Elect a spokesperson
Be prepared to present to class
Group Discussion 2:
You are going to develop a new database. Your group will be assigned one of the following topics:
Collection of music files
Collection of digital photographs
Coin collection or Stamp collection
Large book collection
Develop a list of fields that should be included in your database; indicate the type of field; and determine which would be a good primary key
Form into groups of 4 or 5
Elect a spokesperson
Be prepared to present to class
Group Discussion 3: Handout
Chapter 4 Analyzing the Current Database
Groups should work together following the instructions listed on the handout.
Form into groups of 4 or 5
Elect a spokesperson
Be prepared to present to class
Summary
Described differences between data, info & knowledge
Defined database & identify steps to create one
Described role of a database management system
Described characteristics of a data warehouse &
Defined data mining & describe its role in an organization
Questions
