CORRECT BADM

Primary key

A field that uniquely identifies a record so it can be retrieved, updated, and sorted.

Foreign key

A field (or group of fields) in one table that uniquely identifies a row of another table; links and enforces the relationship between two tables.

Relational database

Based on two-dimensional tables; usually designed as a number of linked tables.

Structured data

Information highly organized in fixed fields in a repository, such as a system of linked tables.

Unstructured data

Information that does not reside in a traditional system of linked tables (email, videos, images, audio files, tweets, web pages).

Binary relationship

An association between two entities.

Ternary relationship

An association among three entities.

Connectivity

The classification of how entities are associated (one-to-one, one-to-many, many-to-many).

One-to-one (1:1)

A single instance of an entity is paired with a single instance of the other entity.

One-to-many

A single instance of an entity is associated with multiple instances of the other entity.

Many-to-many

Multiple instances of each entity can be associated with multiple instances of the other.

Cardinality

The maximum number of times an instance of one entity can be associated with an instance of a related entity; set by business rules.

Four cardinality symbols

Mandatory single, optional single, mandatory many, optional many.

Entity

A category of thing the database tracks, such as STUDENT, PARKING PERMIT, CLASS, or PROFESSOR.

Instance

A specific occurrence of an entity, such as student James Smythe or class 76890; identified by a primary key.

Attribute

A characteristic that describes an entity, such as Student Name or Class Time.

Data warehouse

A repository of historical information organized by subject to support decision makers; read-only, expensive, mostly used by large companies.

Data mart

A cheaper, scaled-down version built for a single department or strategic business unit; often implemented in under 90 days and gives the group local control.

Six characteristics of warehouses and marts

Organized by subject, OLAP, integrated, time variant, nonvolatile, multidimensional.

Organized by subject

Information is grouped by customer, vendor, product, region, etc., rather than by business process (order entry, inventory, accounts receivable).

OLTP

Processes transactions as they happen, with speed and efficiency as the goal; used by transactional databases.

OLAP

Analysis of accumulated information by end users; used by warehouses.

Integrated

Information comes from multiple systems and is unified around subjects (e.g., customer details from many sources tied together by a customer identifier).

Time variant

Keeps years of historical information (transactional systems hold only recent) so organizations can spot trends, deviations, and long-term relationships.

Nonvolatile

Users cannot change the contents; updated only through IT-controlled load processes, so it accurately reflects history.

Multidimensional

Stored in a cube structure with more than two axes, unlike the flat tables of relational systems.

Data cube

The structure in which warehouses hold information along more than two dimensions.

Five parts of a generic warehouse

Source systems; integration technology and processes; storage architectures; tools and applications for users; metadata, quality, and governance processes.

Source systems

Supply the information; often use different software and formats.

Organizational pain point

A business need that drives the requirements for a warehouse.

Metadata

Data about the data.

Transactional databases are optimized for...

Fast, current, one-record-at-a-time operations.

Warehouses and marts are optimized for...

Read-only, historical, subject-organized, multidimensional information that makes trend analysis and decision support fast and easy.

Primary storage

Temporarily holds data and instructions during processing: data for the CPU, CPU instructions, and operating system programs; chips on the motherboard.

Four types of primary storage

Registers, cache memory, RAM, ROM.

Secondary storage

Holds data and programs for future use; very large amounts, extended periods; nonvolatile; slower to retrieve than RAM; cheaper than main memory.

RAM

Part of main memory that holds software and small amounts of data for processing; temporary and usually volatile (loses contents when power is lost); farther from the CPU than registers.

ROM

Chip where critical instructions are safeguarded; nonvolatile, keeps instructions when power is off; the computer can read them but the user cannot change them.

Registers

Part of the CPU with the least capacity; hold extremely limited instructions and data only immediately before and after processing.

Cache memory

High-speed storage that temporarily holds frequently used blocks of data; located closer to the CPU than RAM, so faster.

Human data entry devices

Keyboard, mouse, pointing stick, trackball, joystick, touchscreen, stylus, voice recognition; all require a certain amount of effort by a person.

Source data automation devices

Such as barcode readers; need minimal human intervention, speed up collection, and reduce errors.

Output technologies

Monitors, printers, plotters, and voice.

Bit

A binary digit: either a 0 or a 1.

Byte

A group of 8 bits that represents a single character.

Kilobyte (KB)

Approximately 1,000 bytes.

Megabyte (MB)

Approximately 1 million bytes.

Gigabyte (GB)

Approximately 1 billion bytes.

Terabyte (TB)

Approximately 1 trillion bytes.

Petabyte (PB)

Approximately 1,000 terabytes.

Exabyte (EB)

Approximately 1,000 petabytes.

Zettabyte (ZB)

Approximately 1,000 exabytes.

Internet backbone

Primary connections and telecommunications lines linking the nodes; a fiber-optic system operated mainly by large telecom companies.

Intranet

A private system that uses Internet protocols so users get familiar applications and work habits; supports discovery, communication, and collaboration inside an organization.

Extranet

Connects parts of the intranets of different organizations.

Computer network

A system linking machines and other devices (like printers) via communications media so information can be transmitted among them.

LAN

Connects two or more devices in a limited geographical region, usually within the same building, so every device can communicate with every other.

WAN

Covers a large geographical area; typically connects multiple LANs; provided by common carriers; wide capacity; the Internet is an example.

Router

A communications processor that directs messages from a LAN to the Internet, across several LANs, or across a WAN.

Bandwidth

Transmission capacity of a network, stated in bits per second.

Twisted-pair wire

Inexpensive, widely available, easy to work with; but slow, subject to interference, and easily tapped.

Coaxial cable

Higher bandwidth and less interference than twisted-pair; but more expensive, less flexible, and easily tapped.

Fiber-optic cable

Glass filaments carrying light pulses; very high bandwidth and difficult to tap, but hard to splice.

Dial-up

Still used where broadband is not available.

DSL

Broadband access through telephone companies.

Cable modem

Access over the television company's coaxial line; performance can degrade when many neighbors are online.

Satellite

Internet access used where cable and DSL are not available.

Fiber to the home (FTTH)

Expensive; usually placed only in new housing developments.

Modem

Device that converts digital signals to analog and analog back to digital; the name is short for modulator-demodulator.

Modulation

Converting digital signals to analog signals.

Demodulation

Converting analog signals back to digital signals.

Three basic functions of TCP

Establish a connection between machines to manage packet movement; sequence the transfer of packets; acknowledge packets that have been transmitted.

IP

Responsible for disassembling, delivering, and reassembling data during transmission.

Packet

A small, fixed bundle into which data is divided before it is transmitted over the Internet.

Packet switching

The technology that breaks data into small bundles; each travels independently, possibly by different paths, and they are reassembled at the destination.

Four layers of the TCP/IP model

Application, Transport, Internet, Network Interface.

Application layer

Lets client programs access the other tiers and defines the protocols software uses to exchange data.

Transport layer

Provides the topmost tier with communication and packet services.

Internet layer

Responsible for addressing, routing, and packaging data packets.

Network Interface layer

Places packets on, and receives them from, the transmission medium, which can be any technology.

IPv4

Uses 32 bits; example address 135.62.128.91.

IPv6

Uses 128 bits.

Supercomputer

The most powerful machines, designed for intensive computational demands.

Microcomputer

A small, complete, general-purpose machine, e.g., a laptop.

Microprocessor

Millions of transistors embedded in a circuit on a silicon wafer or chip.

Software

A set of programs that enable the hardware to process data.

System software

Class of instructions that serve as an intermediary between hardware and application programs; provides self-regulatory functions; examples: Windows, Mac OS X, Android, iOS.

Application software

Class of instructions that direct a computer to perform specific processing activities and provide user functionality; examples: MS Office, Chrome, Zoom, Python.

Moore's Law

A 1965 prediction by Intel's cofounder that microprocessor complexity would double about every 18 months, making computers faster, cheaper, and smaller.

Two changes that drive the doubling of microprocessor complexity

Increasingly miniaturized transistors; multiple processors on a single chip (multicore chips).

Information security

All the processes and policies that protect an organization's data and computer-based systems from unauthorized access, use, disclosure, disruption, modification, or destruction.

Threat

Any danger to which a system may be exposed.

Exposure

The harm, loss, or damage that can result if a threat compromises an information resource.

Vulnerability

The possibility that the system will be harmed by a threat.

Risk

The probability that a threat will affect an information resource.

Risk management

Process that identifies, controls, and minimizes the impact of threats, bringing exposure down to acceptable levels.

Three processes of risk management

Analysis, mitigation, and controls evaluation.

Risk analysis

Ensures IS security programs are cost effective.

First step of risk analysis

Assess the value of each asset being protected.

Second step of risk analysis

Estimate the probability that each asset will be compromised.