JMU COB 204 Test #2

Database

a self describing collection of integrated records

Byte

a character of data

Columns

in databases bytes are grouped into this (also called fields)

Rows

in databases columns or fields are grouped into this (also called records)

Table

a group of similar rows or records (also called files)

Primary Key (Key)

a column or group of columns that identifies a unique row in a table

Foreign Key

Key of a different (foreign) table than the one they are in

Relational Databases

Databases that carry their data in the form of tables and represent relationships using foreign keys

Metadata

data that describes data (design view in access)

Database Management System (DMS)

a program used to create, process, and administer a database

Popular DMS's

-DB2 (IBM)

-Access and SQL Server (Microsoft)

-Oracle Database (Oracle Corp.)

-MySQL (OSS)

Structured Query Language (SQL)

an international standard language for processing a database

Database Administration

helps provide tools to assist in the administration of the databases (setting up a security system)

Database Application

a collection of forms, reports, queries, and application programs that serves as an intermediary between users and database data

Form

View data; insert new, update & delete existing data

Reports

Structured presentation of data using sorting, grouping, filtering, and other operations

Queries

Search based on data values provided by the user

Application Programs

provide security, data consistency, and special purpose processing (i.e. handle out-of-stock situations)

Graphical Queries

query criteria are created when the user clicks on a graphic

Multi-User Processing

multiple users processing the same database

Lost-Update Problem

Example of two people attempting to purchase the last 2 tickets because the database didn't recognize one had already added them to their cart

Entity-Relationship Data Model

a tool for constructing data models; used to describe the content of a data model by defining the entities that will be stored in the database and the relationships between them

Entity

something the user want to track (i.e. Order, Customer, Salesperson)

Attributes

describe the characteristics of an entity (i.e. OrderNumber, OrderDate, SubTotal)

Identifier

an attribute or group of attributes whose value is associated with only one entity. (I.e SalespersonName for Salesperson or OrderNumber for Order)

Relationships

Entities have relationships with each other

Entity-Relationship Diagrams

A type of diagram used by database designers to document entities and their relationships to each other

One-To-Many Relationships (1:N)

Relationships involving two entity types in which an instance of one type can relate to many instances of the second type, but the second type can only relate to one instance of the first type

Crow's Foot Notation

shows the maximum # of entities that can be involved in a relationship

Many-To-Many Relationships (N:M)

Relationships involving two entity types in which an instance of one type can relate to many instances of the second and vice-versa

Maximum Cardinality

Max # of entities that can be involved in a relationship

Minimum Cardinality

Min # of entities that can be involved on one side of a relationship

Normalization

the process of converting poorly structured table into two or more well structured tables

Data Integrity Problem

when an organization has inconsistent duplicated data

Normal Forms

A table that does not include any discrepancies that could cause a data integrity problem

ACID Transaction

Atomic- all of a transaction is processed or none of it is

Consistent- transactions are processed in the same manner

Isolated- whether processed alone or in the presence of millions of other transactions

Durable- once a transaction is stored it never goes away, even in the presence of failure

NoSQL DBMS

refers to new DBMS products that support very high transaction rates processing relatively simple data structures, replicated on many servers in the cloud, w/o ACID transaction support

NewSQL DBMS

DBMS products that process very high levels of transactions but provide ACID support

In-memory DBMS

DBMS products that process databases in main memory

The Cloud

the elastic leasing of pooled computer resources over the internet

Mainframes

large-scale high-speed centralized computers

Mainframe Architecture

supports connections between a central mainframe and numerous thin clients

Thin-Client

a computing device that consists of a screen, keyboard, and a network connection

Client-Server Architecture

allows clients (users) to send requests across the Internet to servers. servers respond to clients requests by sending data back to clients

Scalable

easily able to respond to incremental growth in demand

Cloud Computing Architecture

allows employees and customers to access organizational data and applications located in the cloud

Elastic

means that leased computing resources can be increased or decreased dynamically, programmatically, in a short spinoff time and that orgs pay for only the resources used

Pooled

situation in which many different orgs use the same physical hardware

Infrastructure as a Service (IaaS)

cloud hosting of a bare server computer, data storage, network, and virtualization

Platform as a Service (PaaS)

vendors provide hosted computers with an operating system, runtime environment, and middleware like a web server or DBMS

Software as a Service (SaaS)

provides not only hardware infrastructure and an operating system but application programs and databases as well

Content Delivery Network (CDN)

a system of hardware and software that stores user data in many different geographical locations and make those data available on demand

internet

a network of networks

the Internet

collection of networks you use when sending an email or accessing a website

intranet

a private internet used exclusively within an organization

Protocol

a set of rules and data structures for organizing communication

Computer Network

a collection of computers that communicate with one another over transmission lines or wirelessly

Personal Area Network (PAN)

connects devices located around a single person (w/in ~10 meters)

Local Area Network (LAN)

connects computers that reside in a single geographic location on the premises of the company that operates the LAN

Wide Area Network (WAN)

connects computers at different geographic locations

Small Office or Home Office (SOHO)

a business office usually with 10 or fewer employees located in the business professionals home

The Institute for Electrical and Electronics Engineers (IEEE)

sponsors committees that create and publish protocol and other standards

IEEE 802.3 protocol

is used for wired LAN connections; also called ethernet, specifies hardware characteristics (such as which wire carries which signals)

10/100/1000 Ethernet

a type of ethernet that conforms to the IEEE 802.3 protocol and allows for transmission at a rate of 10, 100, or 1,000 Mbps (megabits per second)

IEEE 802.11 protocol

allows speeds of up to 1.3Gbps

Bluetooth

common wireless protocol used to make PAN connections; designed for transmitting data over short distances

Internet Service Provider (ISP)

1. provides a legitimate Internet address

2. serves as gateway to the Internet (back and forth communication)

3. ISP's pay for the internet by collecting money from customers and paying access fees and other charges on your behalf

Digital Subscriber Line (DSL)

A communications line that operates on the same lines as voice telephones but does so as to not interfere with the telephone service signal

Cable Line

provides high speed data transmission using cable lines

WAN wireless

A communications system that provides wireless connectivity to a wide area network

Packet

a formatted message that passes through networks

Domain Name

a worldwide-unique name affiliated with a public IP address

IP Address

# that identifies a particular device

IPv4

four decimal dotted notation (137.190.8.10)

IPv6

six semicolon notation (0:0:0:0:0:ffff:89be:80a)

ICANN (Internet Corporation for Assigned Names and Numbers)

administers a directory naming system, like a phone book, called domain name system

Domain Name System

a directory naming system that assigns domain names to IP addresses

URL (Uniform Resource Locator)

an address on the internet; consists of a protocol (such as http:// or ftp://) followed by a domain name or public IP address

Transmission Control Protocol (TCP)

a core internet protocol that guarantees the reliable delivery of packets

Hop

the movement from one network to another

Routers

devices that connect networks together

Carriers

large telecommunication providers (Verizon, Sprint, AT&T)

Internet Exchange Points (IXP)

Physical location where large carriers exchange traffic

Peering

Exchanging information b/ween telecommunication providers without charging an access fee

Web Page

a document code in (usually) html

Three-Tier Architecture

a design of user computers and servers that consist of three categories or tiers (user, server,database)

User Tier (3tier)

consists of computers, phones, and other mobile devices that have browsers that request and process Web pages

Server Tier (3tier)

consists of computers that run Web servers and process application programs

Database Tier (3tier)

consists of computers that run a DBMS that processes requests to retrieve and store data

Web Server

programs that are run on a server-tier computer and manage traffic by sending and receiving Web pages to and from clients

Commerce Server

an application program that runs on a server-tier computer

Service-Oriented Architecture (SOA)

all interaction among computing devices are defined as services in a formal, standardized way.

TCP/IP Protocol Architecture

protocols that govern the Internet; 5 layers where one or more protocols is defined at each layer

Hypertext Transfer Protocol (http)

the protocol used between browsers and Web servers

Simple Mail Transfer Protocol (smtp)

used for email transmissions

File Transfer Protocol (ftp)

used to move files over the internet

Virtual Private Network (VPN)

uses the internet to create the appearance of private, secure connections

Tunnel

secure connection between the VPN client and VPN server

Private Cloud

a cloud owned and operated by an organization for its own benefit

Virtual Private Cloud (VPC)

a subset of a public cloud that has high restricted, secure access