Chapter 6 Information Technology Systems Flashcards
Programming
-the technique by which we tell computers what we expect of them
-from physical (electronic) standpoint, all information in the computer must be represented by a series circuits which are either “on” or “off”; by convention we far to these values as 1’s and 0’s
Hexadecimal notation
Base 16 to express numbers (versus base 10 - decimal), it’s more compact
Bit, byte, kilobyte, megabyte
Bit = binary digit
Byte=eight bits
Kilobyte=string of 1024 bytes
Megabyte=1024 kilobytes
Assembly language
-Type of computer language
-Machine code is hard to understand
-Uses words and abbreviation in place of long strings and numbers to make programming easier
-Needs another program called an assembler to translate it into machine code
Compiled language
-Type of computer language
-Evolved after assembly language
-Higher-order language
-Needs another program called a compiler to convert the source code into machine code
-Con: needs entire program to be complete before compiler can begin
-Example of compiled language is FORTRAN (Formula Translator), developed by IBM in 1950s
Interpreted language
-Type of computer language
-Evolved after compiled language
-Each line of program is passed through an interpreter for execution and only the part of the program that is immediately needed will be translated
-Con: cost of flexibility is speed
-Example of interpreted language: BASIC (Beginner’s All-purpose Symbolic Instruction Code), appeared on most home computers in the 1980s
Control structures (and example)
linguistic mechanisms that programmers use to tell a computer what to do in a given circumstance
-if/then/else
-for/next: loop
-while loop
Waterfall
-Type of software development
-Origins in manufacturing
-Sequential method where each phase has to be complete before proceeding to next level
-50% of project is spend on Requirements and Design phase
-And then proceed to Implementation (write code), Verification (debugging), and Maintenance
-Type of top-down method
-Critique: project requirement rare remains stationary
Rapid prototyping
-Type of software development
-Start with user interface and then work backwards
-Type of bottom-up approach
Spiral model
-Type of software development
-Developed by Barry Boehm
-Combines waterfall and rapid prototyping
-4 parts: 1) analysis of objectives, alternatives and constraints; 2) evaluation of alternatives and identification of risks, 3) development and verification, 4) planning for the next cycle
Rapid application development (RAD)
-Type of software development
-Like spiral, attempts to break project into smaller chunks
-Adhere to strict timelines or timeboxes
-Involves building completely function models rather than prototypes
-If changes are needed, reduce requirement rather than postpone deadline
Agile software
-Type of software development
-Another iterative method that advocates for a more lightweight and people=centric approach
-Stresses short cycles of continuously improving software
Scrum
-Type of software development
-Variation of agile theme
Extreme Programming (XP)
-Type of software development
-Variation of agile theme
Test-driven Development (TDD)
-Type of software development
-Before any feature is added to project, programmer writes an automated test
-Has library of internal tests
-Critique: not uncommon for the testing code to be much larger than application code
System integration
-process of enabling disparate systems to communicate
-software used to bind two systems is called interface
Vertical integration
-process of integrating systems based on similar functionality
-Tightly integrated systems are called silos
Star integration (or spaghetti integration)
type of system integration where every system talks to everyone else
-expensive but provides best inter-system communication
Horizontal integration (or bus or enterprise service bus)
-when there is a new system created that provides dedicated communication between other systems
-high cost
What standard dictates quality in computer systems
International organization for Standards document (25010)
8 categories:
-functional suitability, performance efficiency, compatibility, usability, reliability, security, maintainability, portability
Schema
rules that enforces what sort of data a database will accept
-The rules or constraints ensure greater data integrity
Normalization
-process of organizing database to reduce data redundancy and improve data integrity
-database is normalized when each row refers to a single indivisible idea “atomic”
-no duplicate information, takes up less storage space, generally easier to modify
Denormalized
-when table is intentionally designed to keep redundant data for performance purposes
-faster to query
Update anomaly
-type of data anomaly
-when an incomplete update causes anomalous data
Insertion anomaly
-type of data anomaly
-inability to add new data to a table because of absence of other data
Deletion anomaly
-type of data anomaly
-deletion of one piece of data causes unintentional loss of other data
Relational DataBase Management System (RDBMS)
-when tables relate to each other
-usually maintain a single, centralized data store and can provide ACID guarantees
NoSQL or object-oriented database
-No schema
-contains document store, each section of the database (often called a collection) contains numerous arbitrary objects called documents
-Often represented in XML or JSON
-No predefined format of documents, designed to easily scale horizontally
-usually distributed over commodity machines in order to provide high availability while sacrificing consistency but not always
ACID (used to describe reliability of database)
-Atomicity: used to describe database transactions that must be done completely or fail completely
-Consistency: any transaction will bring the database from one valid state to another
-Isolation: provides that if the database allows transactions to run concurrently, the database must ensure that the same state would be achieved if they had run sequentially
-Durability: once the transaction is complete, the change has to be permanent, even if there is power loss or computer crashes
Data warehouse
intentional abstraction of a database designed for analytics
Data mart
smaller size of the original data, usually restricted to a particular line of business
OLAP cube
a multidimensional array used for gathering business intelligence
-each axis is called a dimension
-no limit to number of dimensions in an OLAP cube
-the data in each cell is referred to as facts or measures
Types of OLAP operations
-Drill down: break one category into smaller chunks
-Roll up: combining categories into larger chunks
-Slice: holding one dimension constant
-Dice: limiting data based on more than on dimension
-Pivot: rotating data by changing axes
Computer network
-set of protocols and transmission media which allow two or more computers to interact with one another
Node
Any device in a computer network that can send or receive data
Link
The path in a computer network along which data travels
Hub
Is a node in a computer network that allows many other nodes to connect to it
Switch
Similar to a hub in a computer network but more selective
Router
Network device that functions similar to a switch, but sits at junction of two networks and devices which signals should be allowed to pass through
Network Address Translation
Provided by some routers that allows computers to high their actual identity
Layers of computer network
-Lowest levels deal with physical aspects of the network, and higher levels relate to interactions between programs
Open System Interconnect (OSI) model
One of the models to describe networks
-1: physical layer: transmission media, common ones include radio frequency, copper wire, fiber optic
-2: data link: correcting errors in the physical layer and provides synchronization of data transport
(work access layer in TCP/IP model)
-3: network layer: provides routing and switching capabilities
(internet layer in TCP/IP model)
-4: transport layer: employs error-checking algorithms to ensure that data is transported completely and correctly
(transport layer in TCP/IP model)
-5 session layer: responsible for opening and closing communications between software applications
-6 presentation layer: transforms data into usable formats
-7 application layer: higher order interactions (for example authentication, user interaction, quality of service), all application specific
(application layer in TCP/IP model)
Transmission Control Protocol/Internet Protocol (TCP/IP) model
One of the models to describe networks
-Network access: incorporates physical layer, data link in OSI model
-Internet: incorporates network layer in OSI model
-Transport: same as transport layer in OSI model
-Application: incorporates session, presentation, application in OSI model
Network topologies
-Refers to map of connections between different nodes (there’s physical topology that represents physical locations of nodes and interconnects, and logical topology that refers to the way that signals pass from one node to another)
Types of network topologies
-point-to-point: example telephone
-bus: all nodes connected to single wire
-star: all nodes connected to single central node called hub
-ring: every node functions as repeater
-mesh network: each node connected to multiple other nodes, example internet
-tree: star networks linked by a bus, example of hybrid network
-star-ring: series of star connected by a ring, example of hybrid network
-star-star: aka snowflake, example of hybrid network
Public Switched Telephone Network (Plain Old Telephone Service)
global network of telephones and switching
circuit switching
process of sharing finite number of circuits
Cellular phones and Voice-over-IP (VOIP) networks
uses packet switching
Rules of HIPAA
Privacy Rule: defines characteristics of PHI (Protected Health Information): any individually identifiable information
Security Rule: protects e-PHI which includes all health information that a covered entity creates, receives, maintains or transmits in electronic form
Business Associates Agreement
Agreement between Business Associate and a covered entity
Security Rule
-Part of HIPAA
-Has 3 categories:
-Administrative: policies and procedures within an organization to protect PHI
-Physical: limit physical access to data or workstations
-Technical: hardware, software, and other technology that limits access to PHI, categories include
=Aduti controls, access controls, integrity controls, transmission security
Firewall
-device that sits at the junction between 2 networks and devices what kinds of information is allowed to pass through
-packet filter: firewall inspects each packeg
-Stateful inspection: packets are temporarily reassembled on the firewall and examined for prohibited information
Data integrity
-reflects degree to which we can trust our data
-Physical integrity: refers to the way information is stored on various media
-Logical integrity: means that the data makes sense and is appropriate to our needs
Database integrity
-includes 3 requirements
-Entity integrity: requires that every table in the database to have a unique primary key
-Referential integrity: whenever a database column refers to a row in another table, that row exists
-Domain integrity: specifies a specific list of values that are acceptable for a particular column
Data mapping
process by which data is compared or transferred between 2 different data models
4 basic functions for manipulating data
CRUD: Create, Read, Update, Delete
Data mining
Process meant to explore large columns of data
-Includes 3 stages: exploration, model building, and deployment
2 Methods for sharing data between software applications
-Integration: 2 applications share the same data store
-Interfacing: able to communicate with one another and can synchronize data when needed
Methods to meet HIPAA Privacy rule
-de-identification via expert determination method
-de-identification via Safe Harbor Method (remove many identifiers including names, geographic subdivisions smaller than state, dates expect for years, ages over 89, etc.)
