Chapter 3 Databases and Data Warehouses With data everywhere this leads to a greater risk of theft Test 2 Study Guide o How do companies keep their data safe o Do companies keep their data safe Not always How do people steal the information War driving o driving around looking for unsecured wireless networks being used by retailers Sniffer programs o captured credit and debit card numbers as they moved through a retailer s processing computers then tried to sell the data overseas Database o a collection of information organized in a logical structure the logical structure is determined by the type of information Examples o Product information stored by item number o Customer information stored by customer id o Sales information stored by sales id o Relational Database Most popular type of database Consists of 2 or more tables These tables have a relationship with each other A Column are also known as Fields Column Field The Rows are also known as Records Row Record So you want to create a relational database huh well first you got to define it dictionary The structure of a relational database is defined by the data What does the Data Dictionary look like you might ask o How many tables o How many different types of data are in table name o What is the data type for field name in table name So what is it that ties these tables together KEYS KEEYYYYYSS Primary Key o Uniquely describes a row of data in a table Ex Customer Order Employee ID o The FIRST column field of every relational database will be the primary key of that table o If the column is your primary key then NONE of the cells in that column will be the same o A field can be a primary key without having to be a foreign key Foreign Key o This is a field that is a primary key in another table that links two tables o A Foreign Key MUST be a primary key of another table o A column that is a Foreign Field can have cells that hold the same value information they can repeat DBMS o Data Base Management System see bottom image on prior page o Structured Query Language SQL How the database manages it information o Concurrency How the database manages changes to a record if multiple users attempt The Data Warehouse to make changes at the same time o So how is a data warehouse different from a database Data Warehouses are used for decision making rather than just decision processing Warehouses bring in other data form the outside Warehouses are huge collections of data ANNDD because its multidimensional That makes sense A baseball BASE is flat 2 demisional and warehouses are these huge cube like buildings 3 dimensional o Multidimensional o Data Mart Rows and columns AND layers These are subsets of the data warehouse Remember them as departments within the warehouse EX Marketing sales advertising production o So How do we get the information out of the Data Warehouse With a fork lift No Data Mining The process of querying a data warehouse to o Extract meaningful information o Get information to use in business decision making o Get insights form data that are otherwise obvious So why should we keep and analyze all of this data It seems like a lot of work o It s a piece of the organization s overall business intelligence o It s the collective information about customers competitors business partners competitive environment your internal operations o It s used to make strategic business decisions o Helps in understanding the market customers and the competitive environment competitors The key to setting strategy is to have a competitive advantage Therefore treat the organization s information as a resource and make sure to keep it of good quality accurate and secure Network Basis appendix B material Where is the greatest number of Internet users China US Data Consumption in One Day is equal to 3 6 Zeta bytes which is 5 1 Trillion Hard o Two or more computers connected together o they can communicate with each drives What is a network other to Share data and information Share software Share hardware peripheral devices Share computing power o Why are the networks important There is a lot of traffic and data being passed around over the internet therefore having a network that can handle it all is very important o Sizes Well they can be small or large such as Within an organization Connect multiple organizations Simply within your home Or the INTERNET Here s a tip KNOW THIS o Confidentiality Only those authorized to access data can access it Stop someone capturing data as it is transmitted remember sniffing Beware of easily guessed passwords o Authenticity Knowing that information comes from the source it claims to come from Spoofing Email supposed to be o Integrity Knowing that information has not been altered Prevent hacking and network transmission errors o Availability Network services and resources are available when they are Insure that denial of service attacks and network errors or overloads do not occur Malware o A major threat to networks Viruses Trojans Spyware o How do you protect the network Firewalls Intrusion Detection Systems Intrusion Prevention Systems What is the most common type of Network Client Server Network Encryption Virtual Private Networks Networks Characterized by Distance o Local Area Network LAN Covers a small geographic location Usually within a building or between closely located buildings o Wide Area Network WAN Covers a broader geographic location May connect multiple LANs together o Metropolitan Area Network MAN Covers a distance such as a city or large campus May connect multiple LANs together o The Internet How do parts of a network or the Internet connect o Hub Least intelligent least expensive Forwards every packet it receives to every other computer Easy way to connect computers in a small network Like a hub but more intelligent Reads the packet header and forwards it to the correct computer More efficient especially in networks with lots of traffic o Switch o Router Manages traffic on the entire network May connect multiple smaller networks Determines the most efficient least congested route for packets to travel o Bridge Packets Connects two networks together o Everything on the Internet moves in packets EX a web page comes to your computer as a series of packets EX an email travels as a series of packets So why use packets This breaks the transmission into smaller more manageable parts Its like mailing a postcard but ripped into a bunch of pieced with pieces on different trucks and then put back