Good morning! APR2101 Business Information and Communication - - PowerPoint PPT Presentation

Good morning! APR2101 Business Information and Communication

Database Systems, Data Centers, and Business Intelligence

Chapter 5

Principles of Information Systems, Eleventh Edition 2

Why Learn About Database Systems and Business Intelligence?

• Database:

– Organized collection of data

• Database management system (DBMS):

– Group of programs that manipulate the database – Provide an interface between the database and its users and other application programs

• Database administrator (DBA):

– Skilled IS professional who directs all activities related to an organization’s database

Data Management

• Without data and the ability to process it:

– An organization could not successfully complete most business activities

• Data consists of raw facts
• To transform data into useful information:

– It must first be organized in a meaningful way

The Hierarchy of Data

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Data Entities, Attributes, and Keys

• Entity:

– A person, place, or thing for which data is collected, stored, and maintained

• Attribute:

– Characteristic of an entity

• Data item:

– Specific value of an attribute

Data Entities, Attributes, and Keys (continued)

The Database Approach

• Traditional approach to data management:

– Each distinct operational system uses data files dedicated to that system

• Database approach to data management:

– Pool of related data is shared by multiple application programs

The Database Approach (continued)

Data Centers, Data Modeling and Database Characteristics

• When building a database, an organization must

consider:

– Content: What data should be collected and at what cost? – Access: What data should be provided to which users and when? – Logical structure: How should data be arranged so that it makes sense to a given user? – Physical organization: Where should data be physically located?

Data Center

• Climate‐controlled building or set of buildings that

house database servers and the systems that deliver mission‐critical information and services

• Traditional data centers:

– Consist of warehouses filled with row upon row of server racks and powerful cooling systems

Data Center (continued)

• Many organizations now use large shipping

containers packed with racks of servers and cooled to easily connect and set up

• Businesses and technology vendors working to

develop green data centers that run more efficiently and require less energy for processing and cooling

• Backup and security procedures for data

centers can be a concern

Data Modeling

• Data model:

– Diagram of data entities and their relationships

• Enterprise data modeling:

– Starts by investigating the general data and information needs of the organization at the strategic level

• Entity‐relationship (ER) diagrams:

– Data models that use basic graphical symbols to show the

• rganization of and relationships between data

Simplified ER Diagram for a library

Customer Nr. Customer-Nr. Name Address Author-Nr. Name Author written Customer Book Book-Nr. Title borrowed Date

The Relational Database Model

• Relational model:

– Describes data using a standard tabular format – Each row of a table represents a data entity (record) – Columns of the table represent attributes (fields) – The domain is the range of allowable values for data attributes

The Relational Database Model (continued)

• Manipulating data:

– Selecting:

• Eliminates rows according to certain criteria

– Projecting:

• Eliminates columns in a table

– Joining:

• Combines two or more tables

– Linking:

• Manipulating two or more tables that share

at least one common data attribute

The Relational Database Model (continued)

• Data cleanup

– Process of looking for and fixing inconsistencies to ensure that data is accurate and complete – Database normalization is often used to clean up problems with data

Database Management Systems

• Creating and implementing the right database

system ensures that the database will support both business activities and goals

• Capabilities and types of database systems vary

considerably

Overview of Database Types

• Flat file

– Simple database program whose records have no relationship to one another

• Single user

– Only one person can use the database at a time – Examples: Access, FileMaker Pro, and InfoPath

• Multiple users

– Allow dozens or hundreds of people to access the same database system at the same time – Examples: Oracle, Microsoft, Sybase, and IBM

Providing a User View

• Schema:

– Used to describe the entire database – Can be part of the database or a separate schema file

• DBMS:

– Can reference a schema to find where to access the requested data in relation to another piece of data

Providing a User View: Schema

Creating and Modifying the Database

• Data definition language (DDL):

– Collection of instructions and commands used to define and describe data and relationships in a specific database – Allows database’s creator to describe data and relationships that are to be contained in the schema

• Data dictionary:

– Detailed description of all the data used in the database

Creating and Modifying the Database (continued)

Storing and Retrieving Data

• One function of a DBMS is:

– To be an interface between an application program and the database

• Concurrency control

– Method of dealing with a situation in which two or more people need to access the same record in a database at the same time

Storing and Retrieving Data

Selecting a Database Management System

Important database characteristics to consider:

– Database size – Database cost – Concurrent users – Performance – Integration – Vendor

Popular Database Management Systems (continued)

• Database as a Service (DaaS):

– Emerging database system – Database administration is provided by the service provider – The database is stored on a service provider’s servers and accessed by the client over a network

Using Databases with Other Software

• DBMSs can act as front‐end or back‐end

applications:

– Front‐end applications interact directly with people – Back‐end applications interact with other programs or applications

Databases and Application Servers

Internet Application Server End-user Access Application servers manage the process of connecting users to data

• set up an application session
• check each user’s identification and password
• fetch requested information from the appropriate database

Databases

• build the data into a Web page for display to the users

Big Data Applications

• Deals with large amounts of unstructured data from

the Internet, photos, video, audio, social networks, and sensors

• Special big data hardware and software can be more

effective than traditional relational DBMSs

• Some people have concerns that organizations are

harvesting huge amounts of personal data

Data Warehouses, Data Marts, Data Mining

Data Warehouses, Data Marts, and Data Mining (continued)

• Predictive analysis:

– Form of data mining that combines historical data with assumptions about future conditions to predict outcomes

• f events

– Used by retailers to upgrade occasional customers into frequent purchasers – Used to predict future sales up to a year in the future

Distributed Databases

• Distributed database:

– Database in which the data may be spread across several smaller databases connected via telecommunications devices – Gives corporations more flexibility in how databases are

• rganized and used
• Replicated database:

– Holds a duplicate set of frequently used data

Distributed Databases

Enjoy your break!

Welcome back! Telecommunications and Networks

An Overview of Telecommunications

• Telecommunications is the electronic transmission of

signals for communications

• Telecommunications medium is any material

substance that carries an electronic signal to support communications between a sending and receiving device

• Networking protocol is a set of rules, algorithms,

messages, and other mechanisms that enable software and hardware in networked devices to communicate effectively

An Overview Of Telecommunications

Telecommunications devices relay signals between computer systems and transmission media

Communication vs. Communications

Receiver

Message Channel Feedback

Sender

An Overview of Telecommunications

• Communications can be synchronous or

asynchronous

– Synchronous communications: receiver gets message instantaneously – Asynchronous communications: receiver gets message after some delay

Basic Telecommunications Channel Characteristics

• Simplex channel:

– Transmits data in only one direction

• Half‐duplex channel:

– Transmits data in either direction, but not simultaneously

• Full‐duplex channel:

– Permits data transmission in both directions at the same time

Basic Telecommunications Channel Characteristics (continued)

• Channel bandwidth:

– Rate at which data is exchanged, measured in bits/sec

• Circuit switching network:

– Sets up a circuit between the sender and receiver before any communications can occur

• Packet switching network:

– No fixed path is created between the communicating devices

• Telecommunications media

– Categories: guided transmission media and wireless

Basic Telecommunications Channel Characteristics (continued)

• Guided transmission media types:

– Available in many types

• Twisted‐pair wire:

– Shielded or unshielded

• Coaxial cable:

– Offers cleaner and crisper data transmission (less noise) than twisted‐pair wire

• Fiber‐optic cable:

– Transmits signals with light beams

Basic Telecommunications Channel Characteristics (continued)

• Wireless communications options:

– Wireless transmission involves the broadcast of communications in one of three frequency ranges

• Radio, microwave, or infrared frequencies

– In some cases, use of wireless communications is regulated and the signal must be broadcast within a specific frequency range to avoid interference with other wireless transmissions

Short Range Wireless Options

• Near field communication (NFC)

– Short‐range wireless connectivity technology designed for cell phones and credit cards / smart cards

• Bluetooth

– Wireless communications specification that describes how cell phones, computers, personal digital assistants, etc., can be interconnected

Medium‐Range Wireless Options

• Wi‐Fi:

– Wireless telecommunications technology brand owned by the Wi‐Fi Alliance – Employs wireless access point that consists of a transmitter with an antenna that receives the signal and decodes it – Wi‐Fi access points have maximum range of about 100 m

• utdoors and 30 m within a dry‐walled building

Wide Area Wireless Network Types

• Microwave transmission:

– High‐frequency (300 MHz–300 GHz) signal sent through the air – Common forms of satellite communications:

• Geostationary satellite
• Low‐earth orbit (LEO) satellite
• Very small aperture terminal (VSAT)
• Wireless mesh:

– Uses multiple Wi‐Fi access points to link a series of interconnected local area networks

Wide Area Wireless Network Types (continued)

Wide Area Wireless Network Types (continued)

Wide Area Wireless Network Options (continued)

• 3G wireless communications:

– Support wireless voice and broadband speed data communications in a mobile environment

• 4G wireless communications:

– Provides increased data transmission rates in the 5–40 Mbps range

• 5G wireless communications:

– Download a feature length movie in less than2 minutes

Networks and Distributed Processing

• Computer network:

– Consists of communications media, devices, and software needed to connect two or more computer systems or devices – Can transmit and receive information to improve

• rganizational effectiveness and efficiency

Network Types

• Personal area networks (PAN)

– Support interconnection of information technology within a range of about 33 feet

• Local area networks (LAN)

– Connect computer systems and devices within a small area (e.g., office or home)

• Metropolitan area networks (MAN)

– Connect users and their devices in a geographical area that spans a campus or city

• Wide area networks (WAN)

– Connect large geographic regions

Basic Processing Alternatives

• Centralized processing:

– All processing occurs in a single location or facility

• Decentralized processing:

– Processing devices are placed at various remote locations

• Distributed processing:

– Processing devices are placed at remote locations but are connected to each other via a network

Client/Server Systems

• Client/server architecture:

– Multiple computer platforms are dedicated to special functions

• Client:

– Any computer that sends messages requesting services from the servers on the network

• Database server:

– Sends only the data that satisfies a specific query, not the entire file

Client/Server Systems

Telecommunications Hardware

• Smartphones

– Combine the functionality of a mobile phone, camera, Web browser, e‐mail tool, MP3 player, and other devices – Have their own software operating systems

• Modems

– Modulation/demodulation devices

• Multiplexers

– Combine data from multiple data sources into a single

• utput signal that carries multiple channels

Telecommunications Hardware (continued)

Telecommunications Hardware (continued)

• Private branch exchange (PBX)

– Telephone switching exchange that serves a single

• rganization

– Enables users to share outside lines to make calls to people

• utside the organization

– Provides other services such as routing of calls, voice mail, Voice over IP calls, voice paging, three‐way calling, call transfer, and call waiting

Telecommunications Hardware (continued)

• Switches, bridges, routers, and gateways

– Switch: uses the physical device address in each incoming message on the network – Bridge: connects two LANs together using the same telecommunications protocol – Router: forwards data packets across two or more distinct networks toward their destinations – Gateway: serves as an entrance to another network

Telecommunications Software

• Network operating system (NOS):

– Systems software that controls the computer systems and devices on a network

• Network management software:

– Protects software from being copied, modified, or downloaded illegally – Locates telecommunications errors and potential network problems

Securing Data Transmission

• Encryption:

– Converting an original message into a form that can only be understood by the intended receiver

• Encryption key:

– Variable value that is applied (using an algorithm) to a set

• f unencrypted text to produce encrypted text or to

decrypt encrypted text

Securing Data Transmission

Virtual Private Network (VPN)

• Private network that uses a public network (usually

the Internet) to connect multiple remote locations

• Provides network connectivity over a potentially long

physical distance

• Supports relatively secure, encrypted connections

between a company’s private network and remote users

DSL

• Digital subscriber line (DSL) service:

– Telecommunications service that delivers high‐speed Internet access – Asymmetric DSL (ADSL):

• Designed to provide download speed that is three to

four times faster than upload speed – Symmetric DSL (SDSL):

• Used mainly by small businesses
• Does not allow you to use the phone simultaneously
• The speed of receiving and sending data is the same

Call Centers

• Location where an organization handles customer

and other telephone calls

• Used by:

– Customer service organizations – Telemarketing companies – Computer product help desks – Charitable and political campaign organizations

Telecommuting and Virtual Workers and Workgroups

• Telecommuting:

– Use of computing devices and networks so that employees can work effectively away from office

• Telecommuters:

– Need to be strongly self‐motivated, organized, focused on their tasks with minimal supervision

• Jobs unsuitable for telecommuting:

– Those that require frequent face‐to‐face interaction, need much supervision, and have many short‐term deadlines

Electronic Meetings

• Videoconferencing:

– Enables people at multiple locations to communicate using simultaneous two‐way video and audio transmissions – Reduces travel expenses and time – Increases managerial effectiveness through:

• Faster response to problems, access to more people,

and less duplication of effort

Electronic Data Interchange

• Idea behind EDI:

– Connecting corporate computers among organizations

• EDI:

– Can link the computers of customers, manufacturers, and suppliers – Eliminates the need for paper documents and substantially cuts down on costly errors

Electronic Data Interchange

Electronic Data Interchange (continued)

• Electronic funds transfer

– System of transferring money from one bank account directly to another without any paper money changing hands – Used for:

• Credit transfers, such as payroll payments
• Debit transfers, such as mortgage payments

– Benefits:

• Reduced administrative costs
• Increased efficiency
• Simplified bookkeeping and greater security

Quick Response Codes (QR Codes)

• Two dimensional barcode that can be scanned by

users with a smartphone camera with appropriate software to display text or connect to a wireless network and open a Web page in the smartphone’s browser

Global Positioning System Applications

• Global navigation satellite system that uses two

dozen satellites roughly 11,000 miles above the earth

• GPS receivers:

– Have become as small as a cell phone and are relatively inexpensive – Are commonly found in automobiles, boats, planes, laptop computers, and cell phones

Global Positioning System Applications (continued)

• GPS tracking technology:

– Has become the standard by which fleet managers monitor the movement of their cars – Computer‐based navigation systems also based on GPS technology

Please find your Review Questions on the course Web page. Thank you!