IS 312 Midterm - Tao Hu

The Entity Relationship Model

Graphical representation of entities and their relationships in a database structure Entity relationship diagram (ERD): uses graphic representations to model database components Entity instance or entity occurrence: rows in the relational table Attributes: describe particular characteristics Connectivity: term used to label the relationship types

Many-to-many (M:N)

Implemented by creating a new entity in 1:M relationships with the original entities Composite entity (i.e., bridge or associative entity): helps avoid problems inherent to M:N relationships Includes the primary keys of tables to be linked

Layer 2 -Data Link Layer & Layer 1 -Physical Layer

Layers 2 and 1 are responsible for interfacing with physical hardware on the local network. Type of networking hardware or technology used on a network determine the Link Layer protocol used. Ethernet and Wi-Fi are examples. MAC (Media Access Control) address—Hardware address of the source and destination NICs. Also called a physical address, hardware address, or Data Link layer address. Physical layer—Simplest layer and is responsible for sending bits via a wired or wireless transmission.

NOS is responsible for the following activities:

Manages client data, resources, and services Ensures authorized user access Controls user file access Restricts user network access Dictates computer communication rules Supplies applications to clients

Servers that have a NOS installed require:

More memory, processing, and storage capacity Equipped with special hardware Providing network management functions

Layer 3: Network Layer

Network layer: Responsible for moving messages from one node to another until they reach the destination host. IP adds its own Network layer header to the segment or datagram. IP address—Assigned to each node on a network. Network layer uses it to uniquely identify each host. IP relies on several routing protocols to find the best route for a packet to take to reach destination. Network layer protocol will divide large packets into smaller packets: Fragmentation.

Entities

Objects of interest to the end user Refers to the entity set and not to a single entity occurrence In ERM, an entity corresponds to a table in the relational environment A table row as an entity record, instance, or occurrence An entity is represented by a rectangle that contains the entity's name The entity name, a noun, is usually written in all capital letters

Layer 6: Presentation Layer

Presentation layer: Responsible for reformatting, compressing, and/or encrypting data in a way that the receiving application can read. Example: An email message can be encrypted at the Presentation layer by the email client or by the OS.

Layer 4: Transport Layer

Protocols add their own control information in an area at the beginning of the payload (called a header). Encapsulation: Process of adding a header to the data inherited from the layer above. The Transport layer header addresses the receiving application by a number called a port number. If message is too large, TCP divides it into smaller messages called segments.

Difference between router and switch:

Router is like a gateway between networks and belongs to two or more local networks Switch belongs only to its local network

Layer 5: Session Layer

Session layer: Describes how data between applications is synched and recovered if messages don't arrive at the receiving application The Application, Presentation, and Session layers are intertwined. Often difficult to distinguish between them.

Two primary protocols:

TCP (Transmission Control Protocol) IP (Internet Protocol)

Layer 4: Transport Layer

Transport layer: Responsible for transporting Application layer payloads from one application to another Two main Transport layer protocols are: TCP (Transmission Control Protocol)—Makes a connection with the end host, checks whether data was received; called a connection-oriented protocol UDP (User Datagram Protocol): Check whether data is received.

NOS Advantages

User credential assigned from one place Multiple shared resource access centrally controlled Central problem monitoring, diagnostics, and correction capabilities More scalable

IaaS (Infrastructure as a Service)

- Hardware services and network infrastructure devices are provided virtually - Including end user interfaces such as hosted virtual desktops

Sources of business rules

- Company managers - Policy makers - Department managers - Written documentation - Direct interviews with end users

The importance of data modeling

- Facilitates communication Gives various views of the database - Organizes data for users - Provides an abstraction for the creation of a database

Porter Competitive Forces Model

1. The risk of entry by potential competitors 2. The intensity of rivalry among established companies within an industry 3. The bargaining power of buyers 4. The bargaining power of suppliers 5. The closeness of substitutes to an industry's products 6. The power of complement providers (Porter did not recognize this 6th force)

Backbone

A central conduit that connects the segments (pieces) of a network Might use higher transmission speeds and different cabling than network cables connected to computers

Field

A column of data containing a logical grouping of characters, e.g., name, SSN, address, etc.

Client

A computer making a request for data/service from another Clients don't share their resources directly with each other Access is controlled by entries in the centralized domain database Client computers access resources on another computer by way of the servers controlling the domain database

Data warehouse

A database that stores large amounts of historical data in a form that readily supports analysis and management decision making

Router

A device that manages traffic between two or more networks Can help find the best path for traffic to get from one network to another Routers can be used in small home networks to connect the home LAN to the Internet Called a SOHO (small office-home office) network

Relational Database Model (Entity Relationship Diagram -ERD)

A diagram that represents entities in the database and their relationships.

Foreign Key

A field (or group of fields) in one table that uniquely identifies a row of another table. - Used to establish and enforce a link between two tables.

Primary Key

A field in one table that uniquely identify each record - Used to retrieve, update, and sort data in a database.

Operational Effectiveness Strategy

A firm performs business activities more effectively than its rivals.

WAN (wide area network)

A group of LANs that spread over a wide geographical area Internet is the largest and most varied WAN

Metropolitan area network (MAN)

A group of connected LANs in the same geographical area

Windows domain

A logical group of computers that a Windows Server can control: Clients

Database

A logical grouping of related data files (aka database tables)

Record

A logical grouping of related fields in a row.

Data File (Table)

A logical grouping of related records.

Data Marts

A low-cost, scaled-down version of a data warehouse that is designed for the end-user needs in a strategic business unit or an individual department.

Modeling

A model abstracts most of the complexity of the world, focusing on a particular set of objects, events, or entities that are related in some way.

Extranet

A network based on Web technologies that allows selected outsiders to access authorized resources of a company's intranet.

Internet of Things (IoT)

A network of physical objects embedded with sensors, processors, software, and network connectivity capability to enable them to exchange data with the manufacturer of the device, device operators, and other connected devices

Entity

A person, place, thing, or event (e.g., customer, an employee, or a product).

Virtual Private Network(VPN)

A private network that uses the Internet to connect users. VPNs essentially integrate the global connectivity of the Internet with the security of a private network and thereby extend the reach of the organization's networks. Sometimes referred to as a tunnel

Data Warehouses

A repository of historical data that are organized by subject to support decision making.

Value Chain

A sequence of activities through which the organization's inputs are transformed into more valuable outputs.

Cloud computing

A service provider organization owns and manages the hardware, software, networking, and storage devices in order to provide shared resources to users via the Internet

Enterprise resource planning (ERP)

A set of integrated programs - Manages the vital business operations for an entire multisite, global organization

OSI (Open Systems Interconnection) reference model

A seven-layer model developed to categorize the layers of communication. The layers are numbered in order, starting with Layer 1, the Physical layer at the bottom. Physical, Data Link, Network, Transport, Session, Presentation, Application.

Database Management Systems (DBMS)

A software system to create, maintain, and provide controlled access to data and database. Minimize: Data redundancy, data isolation, data inconsistency Maximize: data security, data integrity, data independence

Big Data

A term used to describe data collections that are so enormous that traditional data management software, hardware, and analysis processes are incapable of dealing with them. - The amount of data increases exponentially over time

Digital divide

A term used to describe the gulf between those who do and those who don't have access to modern information and communications technology

Hybrid topology

A topology that combines topologies

Virtualization

A virtual, or logical, version of something rather than the actual, or physical, version

Star topology

All devices connect to one central device (usually a switch)

Traditional cloud services

All hardware, software, and everything else is located and managed at the organization's location

Database

An organized collection of facts and information, typically consisting of two or more related data files - Can contain facts and information on customers, employees, inventory, sales, online purchases, etc...

Transaction processing system (TPS)

An organized collection of people, procedures, software, databases, and devices - Used to perform and record completed business transactions

Transaction

Any business-related exchange, such as payments to employees and suppliers and sales to customers

Layer 7: Application Layer

Application layer—Describes the interface between two applications, on separate computers. Application layer protocols are used by programs that fall into two categories: Provide services to a user, such as a browser and Web server Utility programs that provide services to the system that monitor and gather information about network traffic. Payload—Data that is passed between applications or utility programs and the OS.

SaaS (Software as a Service)

Applications

Relational Database Model

Based on the concept of two-dimensional tables - Designed with a number of related tables - Each table contains records in rows and attributes in columns.

Entity name requirements

Be descriptive of the objects in the business environment Use terminology that is familiar to the users

Business Understanding

Brief precise description of a policy, procedure, or principle of a business - Create and enforce actions within that organization's environment - Establish entities, relationships and constraints

Technology Pressures

Business pressures caused by - Technological innovation and obsolescence: Legacy vs. Cutting Edge - Information overload: End users must be able to access, navigate, and utilize vast stores of data, information, and knowledge.

Market Pressures

Business pressures generated by: - Global economy (Globalization) - Intense competition - Changing nature of the workforce: Diversified workforce - Powerful customers: Customers (informed users) become more knowledgeable about the products and services

Societal/Political/Legal Pressures

Business pressures related to: - Social responsibility: physical environment, philanthropy, education, and other social problems - Government regulation/deregulation regarding health, safety, environmental protection, equal opportunity... - Spending for social programs - Spending to protect against terrorism - Ethics: e.g., standards of right and wrong in information processing practices

Business application software

Can be categorized by whether it is intended to be used by an individual, a small business, or a large multinational enterprise

Senior IS Managers

Central role of all of the above is to communicate with other areas of the organization to determine changing business needs

Attributes

Characteristics of entities Domain: set of possible values for a given attribute Identifier: one or more attributes that uniquely identify each entity instance Composite identifier: primary key composed of more than one attribute

Key pair

Combination of public and private keys

Hybrid cloud

Combination of the other service models into a single deployment

Nodes or hosts

Computers form a logical group of computers and users, may share resources, may prevent access to resources

Networks

Connect computers and equipment in a room, building, campus, city, or globally to enable electronic communication

Hardware

Consists of computer equipment used to perform input, processing, storage, and output activities - A trend in the industry is to produce smaller, faster, and more mobile hardware

Software

Consists of the computer programs that govern the operation of a particular computing device

Network operating system (NOS)

Controls access to the entire network

Public key encryption

Data encrypted using two keys • Private key: user knows • Public key: anyone may request

Clickstream Data

Data that visitors produce when they visit a Web site and click on hyperlinks: User behavior and browsing patterns.

Data dictionary

Description of all tables in the database created by the user and designer

Guest

Each virtual machine

Intranet

Enable communication, collaboration, search functions, and information sharing between member of an organization using a Web browser.

Internet of Everything

Encompasses not only machine-to-machine but also people-to-people and people-to-machine connections

SQL (Structured Query Language)-based relational database application

End-user interface Allows end user to interact with the data Collection of tables stored in the database Each table is independent from another Rows in different tables are related based on common values in common attributes

Cloud computing

Flexible provision of data storage, applications, and services to multiple clients over a network

Logical topology

Has to do with software and describes how access to the network is controlled How users and programs initially gain access to the network

Strategic Information Systems

Help an organization implement its strategic goals and improve its performance and productivity.

Digital certificate

Holds identification information and the user's public key

Topology

How parts of a whole work together

Business intelligence (BI)

Includes a wide range of applications, practices, and technologies for the extraction, transformation, integration, visualization, analysis, interpretation, and presentation of data to support improved decision making

Value System

Includes the suppliers that provide the inputs necessary to the firm along with their value chains. After the firm creates products, these products pass through the value chains of distributors (which also have their own value chains), all the way to the customers.

Relationship Degree

Indicates the number of entities or participants associated with a relationship

Innovation Strategy

Introduce new products and services, add new features to existing products and services, or develop new ways to produce them .

Certificate authority

Issues, maintains digital certificates

Protocols

Methods and rules for communication between networked devices

Physical topology

Mostly applies to hardware and describes how computers, devices, and cables fit together to form the network

Cybercriminals

Motivated by the potential for monetary gain - Hack into computers systems to steal

One-to-many (1:M)

Norm for relational databases

Business rules for the proper identification of entities, attributes, relationships, and constraints

Nouns translate into entities Verbs translate into relationships among entities

PaaS (Platform as a Service)

OS, runtime libraries or modules the OS provides to applications, and the hardware on which the OS runs

Differentiation Strategy

Offering different products, services, or product features than competitors.

Cloud computing features

On-demand service • Support for multiple platforms • Resource pooling and consolidation • Metered service • Elastic services and storage - Storage capacity can quickly or automatically be scaled up or down

One-to-one (1:1)

One entity can be related to only one other entity and vice versa

Optional participation

One entity occurrence does not require a corresponding entity occurrence in a particular relationship

Mandatory participation

One entity occurrence requires a corresponding entity occurrence in a particular relationship

Data Integration

Organizations need to ETL data from data sources into a data warehouse.

Management information system (MIS)

Organized collection of people, procedures, software, databases, and devices - Provides routine information to managers and decision makers - Focuses on operational efficiency - Provides standard reports generated with data and information from the TPS or ERP

Host

Physical computer "hosting" a virtual machine

Data Rot

Physical problems with storage media that make it difficult to access data.

System acquisition

Process used to obtain the information system resources needed to provide the services necessary to meet a specific set of needs

Cost leadership strategy:

Produce products and/or services at the lowest cost in the industry.

Mass Customization

Producing a large quantity of items, but it customizes them to match the needs and preferences of individual customers.

Make-to-Order

Producing customized (made to individual specifications) products and services.

ERP system benefits

Provide a global view of operational/planning data Lower the cost of doing business Ensure compliance Automate core business operations Improve customer service Reduce time to market by sharing evolving product data

Public key server:

Publicly accessible host • Freely provides users' public keys

Relationships are bidirectional

Questions to identify the relationship type How many instances of B are related to one instance of A? How many instances of A are related to one instance of B?

Extract-transform-lead (ETL) process

Raw data is extracted from various sources, transformed into a format that will support analysis, and then loaded into the data warehouse

Switch

Receives incoming data from one of its ports and redirects it to another port or multiple ports Will send the data to its intended destination

Attribute name

Required to be descriptive of the data represented by the attribute

The use of information about people

Requires balancing the needs of those who want to use the information against the rights and desires of the people whose information may be used

Asymmetric encryption

Requires two different keys

A server computer

Resources are managed by the network operating system (NOS) via a centralized directory database

Symmetric encryption

Same key used during both encryption and decryption

Private cloud

Service established on an organization's own servers in its own data center

Public cloud

Service provided over public transmission lines

Community cloud

Service shared between multiple organizations

Remote access

Service that allows a client to connect with and log on to a server, LAN, or WAN in a different geographical location • Requires a type of remote access server

Data model

Simple representation of complex real-world data structures - Useful for supporting a specific problem domain

PAN (personal area network)

Smallest network A network of personal devices such as your smartphone and your computer

Reasons for identifying and documenting business rules

Standardize company's view of data Facilitate communications tool between users and designers Assist designers Understand the nature, role, scope of data, and business processes Develop appropriate relationship rules and constraints Create an accurate data model

Data

Stored representations of meaningful objects and events in an organizational setting.

Support activities

Support the primary activities, but do not add value directly to the firm's products or services. - The firm's infrastructure (accounting, finance, management) •Human resources management •Product and technology development •Procurement

System catalog

System data dictionary that describes all objects within the database

System development

The activity of building information systems to meet users' needs - IS Projects can range from small to very large

Difficulties of Managing Data

The amount of data increases exponentially over time

knowledge

The awareness and understanding of a set of information and the ways that information can be made useful to support a specific task or reach a decision.

Active Directory (AD)

The centralized directory database that contains user account information and security for the entire group of client computers A user can sign on to the network from any computer on the network and gain access to the resources This process is managed by Active Directory Domain Services (ADDS)

Business Environment

The combination of social, legal, economic, physical, and political factors in which businesses operate. - Significant changes in any of these factors are likely to create Business Pressures on organizations.

Internet censorship

The control or suppression of the publishing or accessing of information on the Internet

Business analytics

The extensive use of data and quantitative analysis to support fact-based decision making within organizations

Cyberterrorism

The intimidation of a government or a civilian population by using information technology to disable critical national infrastructure - To achieve political, religious, or ideological goals

Net neutrality

The principle that Internet service providers (ISPs) should be required to treat all Internet traffic running over their networks the same

Network services

The resources and computing services a network makes available to its users Includes applications, data, and computing services provided by these applications

Bus topology

Three switches daisy-chained together in a single line However, each switch is connected to computers via a star topology, making it a star-bus topology

Volume

To put these volumes into perspective using the classic grains of sand analogy: A megabyte is a tablespoon of sand; A terabyte is a sandbox twofeet wide and one-inch deep; A petabyte is a mile-long beach; An exabyte is a beach extending from Maine to North Carolina.

Public key Infrastructure

Use of certificate authorities to associate public keys with certain users

Strategic planning

Used to improve alignment between the needs of the business and the activities of the information systems organization

Associative (Composite) Entities

Used to represent an M:N relationship between two entities Has a 1:M relationship with the parent entities Composed of the primary key attributes of each parent entity May also contain additional necessary attributes

Local area network (LAN):

Usually contained in a small space such as a office or building

Internet

World's largest computer network

Electronic business

a broader concept servicing customers, collaborating with business partners, and performing electronic transactions within an organization.

process

a set of logically related tasks performed to achieve a defined outcome - Turning data into information is a process

Application software

allows you to accomplish specific tasks, including editing text documents, creating graphs, and playing games

Competitive Advantage

any assets that provide an organization with an edge against its competitors. For example: •Cost •Quality •Speed •Market control •Larger-than-average profits

Relationship

association among entities - one to many (1:M) - many to many (M:N) - one to one (1:1)

Unary relationship

association is maintained within a single entity

Primary key

attribute or combination of attributes that uniquely identifies a row

Relationship

between entities that always operate in both directions

Attribute

characteristic of an entity

information

collection of data organized in such a way that they have value beyond the facts themselves - One of an organization's most valuable resources - Often confused with the term data

External Data Sources

commercial databases, government reports, and corporate Web sites.

Keys

consist of one or more attributes that determine other attributes Ensure that each row in a table is uniquely identifiable Establish relationships among tables and to ensure the integrity of the data

Internal Data Sources

corporate databases and company documents

Data modeling

creating a specific data model for a determined problem domain

procedure

defines the steps to follow to achieve a specific end result - Such as enter a customer order, pay a supplier invoice, or request a current inventory report - Using a CBIS involves setting and following many procedures, including those for the operation, maintenance, and security of the system

Connectivity

describes the relationship classification - Include 1:1, 1:M, and M:N

Peer-to-peer (P2P) network model

each computer on the network is responsible for controlling access to its resources

Chief information officer (CIO)

employs the IS department's equipment and personnel to help the organization attain its goals

Participants

entities that participate in a relationship

Cardinality

expresses the minimum and maximum number of entity occurrences associated with one occurrence of related entity

technology infrastructure

includes all hardware, software, databases, networks, people, and procedures - Configured to collect, manipulate, store, and process data into information

Group IS

includes information systems that improve communications and support collaboration among members of a workgroup

Personal IS

includes information systems that improve the productivity of individual users

Enterprise IS

includes information systems that organizations use to define structured interactions among their own employees and/or external customers, suppliers, government agencies

E-commerce

involves the exchange of money for goods and services over electronic networks

Data degradation

is the gradual corruption of computer data due to an accumulation of non-critical failures over time.

TCP/IP suite of protocols

is used by OS for communication on a network

Alignment

means that the IS organization and its resources are focused on efforts that support the key objectives defined in the strategic plan of business

Network interface card (NIC)

network port used to attach a device to a network

System software

oversee basic computer operations such as start-up, controls access to system resources, and manages memory and files

Entity

person, place, thing, or event about which data will be collected and stored

Customer Personal Data Sources

personal thoughts, opinions, and experiences.

Strategic Systems

provide organizations with advantages to: - Increase market share and/or profits - Better negotiate with suppliers - Prevent competitors from entering markets

Customer Focus

provide superb customer service that can make the difference between attracting and retaining customers.

data

raw facts

Primary Activities

relate to the production and distribution of the firm's products and services. These activities create value for which customers are willing to pay. 1.Inbound logistics (inputs) 2.Operations (manufacturing and testing) 3.Outbound logistics (storage and distribution) 4.Marketing and sales 5.Services

Constraint

restriction placed on data, e.g., update, delete, edit, add, etc. - Ensures data integrity

Information System (IS)

set of interrelated elements that collect (input), process, store, disseminate data and information, provides a feedback mechanism to monitor and control is operation to make sure it continues to meet its goals and objectives

computer-based Information System

single set of hardware, software, databases, networks, people, and procedures - Configured to collect, manipulate, store, and process data into information

Electronic commerce

the process of buying, selling, transferring, or exchanging products, services, or information via computer networks, e.g., the Internet.

Mobile commerce (m-commerce)

the use of mobile, wireless devices to place orders and conduct business - Used to support all forms of e-commerce: - Business-to-business (B2B) - Business-to-consumer (B2C) - Consumer-to-consumer (C2C) - Government-to-citizen (G2C)

Ternary relationship

three entities are associated

Binary relationship

two entities are associated

E-business

use of information systems and the Internet to perform business-related tasks and functions

XaaS (Anything as a Serviceor Everything as a Service):

• A broader model • Cloud can provide any combination of functions

VPN concentrator

• Authenticates VPN clients • Establishes tunnels for VPN connections • Manages encryption for VPN transmissions

Disadvantages of virtualization:

• Compromised performance • Increased complexity • Increased licensing costs • Single point of failure

Hypervisor

• Creates and manages a VM • Manages resource allocation and sharing between a host and any of its guest VMs

Private key encryption

• Data encrypted using single key - Known only by sender and receiver

Two types of remote access servers:

• Dedicated devices • Software running on a server

Remote Access Policies

• Devices used for remote access must be kept up to date with patches, anti-malware software, and a firewall • Device access must be controlled by a strong password or biometric measures • Passwords must be strong and must be changed periodically • The device's internal and external storage devices must be encrypted • Company and customer data that is accessed, transferred, stored, or printed must be kept secure • The loss or theft of any devices used for remote access must be reported to the company immediately

Advantages of virtualization:

• Efficient use of resources • Cost and energy savings • Fault and threat isolation • Simple backups, recovery, and replication

Types of remote access:

• Point-to-point over a dedicated line • Remote virtual computing • Virtual private network (VPN)

Key:

• Random string of characters • Woven into original data's bits • Generates unique data block called ciphertext • Created according to a specific set of rules (algorithms)

Data is often encrypted before it is transmitted over the remote connection:

• Some remote access protocols natively include encryption functionality • Others must be paired with a specific encryption protocol

Way to reduce risks of cloud computing:

• Use encryption • Carefully choose the method by which your network connects to cloud resources: - Internet - Remote access connections - Leased line - Dedicated connection

Encryption

• Use of mathematical code, called a cipher, to scramble data into a format that can be read only by reversing the cipher • Used to keep information private • Primarily evaluated by three benchmarks: - Confidentiality - Integrity - Availability

In client-server applications:

A client computer requests data or a service from a server computer

Activities involved in building ERD

Create a detailed narrative of the organization's description of operations Identify business rules based on the descriptions Identify main entities and relationships from the business rules Develop the initial ERD Identify the attributes and primary keys that adequately describe entities Revise and review ERD

Database designers must often make design compromises that are triggered by conflicting goals

Database design must conform to design standards and procedures High processing speed may limit the number and complexity of logically desirable relationships Maximum information generation may lead to loss of clean design structures and high transaction speed

Entity Relationship Model

Forms the basis of an entity relationship diagram (ERD) Conceptual database as viewed by end user Include a database's main components Entities Attributes Relationships