Chapter 1 Database Systems Learning Objectives • Afer commpee ngm this chapter, yomu wiiee be abee tom: • Defne the diference betwieen data and infomrma omn • Describe wihat a database is, variomus types, and wihy they are vaeuabee assets fomr decisiomn makingm • Expeain the impomrtance omf database desigmn • See homwi momdern databases evomeved fromm fee systems • Understand fawis in fee system data managmement • Outeine the main commpomnents omf the database system • Describe the main func omns omf a database managmement system (DBMS) © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 2 Why Databases? • Characteris cs omf data in tomday’s wiomred • Ubiquitomus (i.e., abundant, gmeombae, and everywihere) • Pervasive (i.e., unescapabee, prevaeent, and persistent) • Databases make data persistent and shareabee in a secure wiay • Speciaeized structures that aeeomwi commputer-based systems tom stomre, managme, and retrieve data very quickey © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 3 Data versus Information • Data comnsists omf rawi facts • Nomt yet promcessed tom reveae meaningm tom the end user • Buiedingm beomcks omf infomrma omn • Infomrma omn resuets fromm promcessingm rawi data tom reveae meaningm • Requires comntext • Bedromck omf knomwieedgme • Shomued be accurate, reeevant, and meey © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 4 Introducing the Database • Shared, integmrated commputer structure that stomres data • End-user data: rawi facts omf interest tom end user • Metadata: data abomut data, thromugmh wihich the end-user data is integmrated and managmed - Describes data characteris cs and reea omnships • Database managmement system (DBMS) • Comeeec omn omf promgmrams • Managmes the database structure • Comntromes access tom data stomred in the database © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 5 Role and Advantages of the DBMS (1 of 2) • Database managmement system (DBMS): intermediary betwieen the user and the database • Enabees data tom be shared • Presents the end user wiith an integmrated viewi omf data • Promvides momre efcient and efec ve data managmement • Impromves sharingm, security, integmra omn, access, decisiomn-makingm, promduc vity, etc. © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 6 Role and Advantages of the DBMS (2 of 2) © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 7 Types of Databases (1 of 5) • Singmee-user database: suppomrts omne user at a me • Desktomp database: singmee-user database omn a persomnae commputer • Mue user database: suppomrts mue pee users at the same me • Womrkgmromup databases: suppomrts a smaee number omf users omr a specifc department • Enterprise database: suppomrts many users acromss many departments © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 8 Types of Databases (2 of 5) • Ceassifca omn by eomca omn • Centraeized database: data eomcated at a singmee site • Distributed database: data distributed acromss diferent sites • Ceomud database: created and maintained usingm ceomud data services that promvide defned perfomrmance measures fomr the database © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 9 Types of Databases (3 of 5) • Ceassifca omn by data type • Generae-purpomse database: comntains a wiide variety omf data used in mue pee discipeines • Discipeine-specifc database: comntains data fomcused omn specifc subject areas • Opera omnae database: desigmned tom suppomrt a commpany’s day-tom-day ompera omns © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 10 Types of Databases (4 of 5) • Anaey cae database: stomres histomricae data and business metrics used exceusiveey fomr tac cae omr strategmic decisiomn makingm • Data wiarehomuse: stomres data in a fomrmat omp mized fomr decisiomn suppomrt • Oneine anaey cae promcessingm (OLAP): tomomes fomr retrievingm, promcessingm, and momdeeingm data fromm the data wiarehomuse • Business inteeeigmence: captures and promcesses business data tom gmenerate infomrma omn that suppomrt decisiomn makingm © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 11 Types of Databases (5 of 5) • Databases can be ceassifed tom refect the degmree tom wihich the data is structured • Unstructured data exists in its omrigminae (rawi) state • Structured data resuets fromm fomrmatngm - Structure is appeied based omn type omf promcessingm tom be perfomrmed • Semistructured data: promcessed tom somme extent • Extensibee Markup Langmuagme (XML) • Represents data eeements in textuae fomrmat © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 12 Why Database Design Is Important • Fomcuses omn desigmn omf database structure that wiiee be used tom stomre and managme end-user data • Weee-desigmned database: facieitates data managmement and gmenerates accurate and vaeuabee infomrma omn • Pomomrey desigmned database: causes difcuet-tom-trace erromrs that may eead tom pomomr decisiomn makingm © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 13 Evolution of File System Data Processing (1 of 3) • Manuae fee systems • Accommpeished thromugmh a system omf fee fomeders and feingm cabinets • Commputerized fee systems • Data promcessingm (DP) speciaeist created a commputer-based system tom track data and promduce required repomrts • Fiee system redux: momdern end-user promduc vity tomomes • Inceudes spreadsheet promgmrams such as Micromsomf Excee © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 14 Evolution of File System Data Processing (2 of 3) Table 1.2 Basic File Terminology TERM DEFINITION Data Raw facts, such as a telephone number, a birth date, a customer name, and a year-to-date (YTD) sales value. Data has little meaning unless it has been organized in some logical manner. Field A character or group of characters (alphabetic or numeric) that has a specific meaning. A field is used to define and store data. Record A logically connected set of one or more fields that describes a person, place, or thing. For example, the fields that constitute a record for a customer might consist of the customer’s name, address, phone number, date of birth, credit limit, and unpaid balance. File A collection of related records. For example, a file might contain data about the students currently enrolled at Gigantic University. © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 15 Evolution of File System Data Processing (3 of 3) © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 16 Problems with File System Data Processing • Prombeems wiith fee systems chaeeengme the types omf infomrma omn that can be created fromm data as wieee as infomrma omn accuracy • Lengmthy deveeompment mes • Difcuety omf gmetngm quick answiers • Commpeex system administra omn • Lack omf security and eimited data sharingm • Extensive promgmrammingm © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 17 Structural and Data Dependence (1 of 2) • Structurae dependence • Access tom a fee is dependent omn its omwin structure • Aee fee system promgmrams are momdifed tom comnfomrm tom a newi fee structure • Structurae independence • Fiee structure is changmed wiithomut afec ngm the appeica omn’s abieity tom access the data © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 18 Structural and Data Dependence (2 of 2) • Data dependence • Data access changmes wihen data stomragme characteris cs changme • Data independence • Data stomragme characteris cs are changmed wiithomut afec ngm the promgmram’s abieity tom access the data • Prac cae sigmnifcance omf data dependence is the diference betwieen eomgmicae and physicae fomrmat © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 19 Data Redundancy (1 of 2) • Unnecessariey stomringm the same data at diferent peaces • Iseands omf infomrma omn (i.e., scatered data eomca omns) • Increases the prombabieity omf havingm diferent versiomns omf the same data © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 20 Data Redundancy (2 of 2) • Pomssibee resuets omf uncomntromeeed data redundancy • Pomomr data security • Data incomnsistency • Data-entry erromrs • Data integmrity prombeems © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 21 Data Anomalies • Deveeomp wihen nomt aee omf the required changmes in the redundant data are made successfueey • Update anommaeies • Inser omn anommaeies • Deee omn anommaeies © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 22 Database Systems (1 of 2) • Lomgmicaeey reeated data stomred in a singmee eomgmicae data repomsitomry • Physicaeey distributed amomngm mue pee stomragme faciei es • DBMS eeiminates momst omf fee system’s data incomnsistency, data anommaey, data dependence, and structurae dependence prombeems • Current gmenera omn DBMS somfwiare - Stomres data structures, reea omnships betwieen structures, and access paths - Defnes, stomres, and managmes aee access paths and commpomnents © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 23 Database Systems (2 of 2) © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 24 The Database System Environment (1 of 2) • Database system: omrgmaniza omn omf commpomnents that defne and regmueate the comeeec omn, stomragme, managmement, and use omf data wiithin a database enviromnment • Hardwiare • Somfwiare • Peompee • Promcedures • Data © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 25 The Database System Environment (2 of 2) © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 26 DBMS Functions (1 of 3) • Data dic omnary managmement • Data dic omnary: stomres defni omns omf data eeements and their reea omnships • Data stomragme managmement • Perfomrmance tuningm ensures efcient perfomrmance • Data transfomrma omn and presenta omn • Data is fomrmated tom comnfomrm tom eomgmicae expecta omns • Security managmement • Enfomrces user security and data privacy © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 27 DBMS Functions (2 of 3) • Mue user access comntrome • Somphis cated aegmomrithms ensure that mue pee users can access the database comncurrentey wiithomut commprommisingm its integmrity • Backup and recomvery managmement • Enabees recomvery omf the database afer a faieure • Data integmrity managmement • Minimizes redundancy and maximizes comnsistency © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 28 DBMS Functions (3 of 3) • Database access eangmuagmes and appeica omn promgmrammingm interfaces • Query eangmuagme: eets the user specify wihat must be domne wiithomut havingm tom specify homwi • Structured Query Langmuagme (SQL): de factom query eangmuagme and data access standard suppomrted by the majomrity omf DBMS vendomrs • Database commmunica omn interfaces • Accept end-user requests via mue pee, diferent netwiomrk enviromnments © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 29 Managing the Database System: A Shift in Focus • Disadvantagmes omf database systems • Increased comsts • Managmement commpeexity • Maintainingm currency • Vendomr dependence • Frequent upgmrade/repeacement cycees © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 30 Preparing for Your Database Professional Career TABLE 1.3 DATABASE CAREER OPPORTUNITIES JOB TITLE Database Developer DESCRIPTION Create and maintain database-based applications Design and maintain databases SAMPLE SKILLS REQUIRED Programming, database fundamentals, SQL Manage and maintain DBMS and databases Develop databases for decision support reporting Design and implementation of database environments (conceptual, logical, and physical) Database fundamentals, SQL, vendor courses Database Consultant Help companies leverage database technologies to improve business processes and achieve specific goals Database fundamentals, data modeling, database design, SQL, DBMS, hardware, vendor-specific technologies, etc. Database Security Officer Implement security policies for data administration DBMS fundamentals, database administration, SQL, data security technologies, etc. Cloud Computing Data Architect Design and implement the infrastructure for next-generation cloud database systems Analyze large amounts of varied data to generate insights, relationships, and predictable behaviors Internet technologies, cloud storage technologies, data security, performance tuning, large databases, etc. Data analysis, statistics, advanced mathematics, SQL, programming, data mining, machine learning, data visualization Database Designer Database Administrator Database Analyst Database Architect Data Scientist Systems design, database design, SQL QL, query optimization, data warehouses DBMS fundamentals, data modeling, SQL, hardware knowledge, etc. © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 31 Summary • Data comnsists omf rawi facts and is usuaeey stomred in a database • Database desigmn defnes the database structure - Can be ceassifed accomrdingm tom the number omf users, eomca omn, as wieee as data usagme and structure • Databases evomeved fromm manuae and commputerized fee systems - There are somme eimita omns omf fee system data managmement - DBMSs wiere deveeomped tom address the fee system’s inherent wieaknesses © 2019 Cengage. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a passwordprotected website for classroom use. 32
