6.6.11

CHAPTER 6. MANAGING CHAPTER 6. MANAGING DATA RESOURCESDATA RESOURCES

6.6.22

LEARNING OBJECTIVESLEARNING OBJECTIVES

• COMPARE TRADITIONAL FILE COMPARE TRADITIONAL FILE ORGANIZATION & MANAGEMENT ORGANIZATION & MANAGEMENT TECHNIQUESTECHNIQUES

• EXPLAIN PROBLEMS OF TRADITIONAL EXPLAIN PROBLEMS OF TRADITIONAL FILE ENVIRONMENTFILE ENVIRONMENT

• DESCRIBE HOW DATABASE DESCRIBE HOW DATABASE MANAGEMENT SYSTEM MANAGEMENT SYSTEM ORGANIZES ORGANIZES INFORMATIONINFORMATION

**

6.6.33

LEARNING OBJECTIVESLEARNING OBJECTIVES

• IDENTIFY TYPES OF DATABASE, IDENTIFY TYPES OF DATABASE, PRINCIPLES OF DATABASE DESIGNPRINCIPLES OF DATABASE DESIGN

• DISCUSS DATABASE TRENDSDISCUSS DATABASE TRENDS• ANALYZE MANAGERIAL, ANALYZE MANAGERIAL,

ORGANIZATIONAL REQUIREMENTS FOR ORGANIZATIONAL REQUIREMENTS FOR CREATING DATABASE CREATING DATABASE ENVIRONMENTENVIRONMENT

**

6.6.44

MANAGEMENT CHALLENGESMANAGEMENT CHALLENGES

• TRADITIONAL DATA FILE TRADITIONAL DATA FILE ENVIRONMENTENVIRONMENT

• DATABASE ENVIRONMENTDATABASE ENVIRONMENT

• DESIGNING DATABASESDESIGNING DATABASES

• DATABASE TRENDSDATABASE TRENDS

• MANAGEMENT REQUIREMENTS FOR MANAGEMENT REQUIREMENTS FOR DATABASE SYSTEMSDATABASE SYSTEMS

**

6.6.55

FILE ORGANIZATIONFILE ORGANIZATION

• BIT:BIT: Binary Digit (0,1; Y,N; On,Off)Binary Digit (0,1; Y,N; On,Off)

• BYTE:BYTE: Combination of BITS which Combination of BITS which represent a CHARACTERrepresent a CHARACTER

• FIELD:FIELD: Collection of BYTES which Collection of BYTES which represent a DATUM or Factrepresent a DATUM or Fact

• RECORD:RECORD: Collection of FIELDS which Collection of FIELDS which reflect a TRANSACTIONreflect a TRANSACTION

**

6.6.66

FILE ORGANIZATIONFILE ORGANIZATION

• FILE:FILE: A Collection of Similar A Collection of Similar RECORDSRECORDS

• DATABASE:DATABASE: An Organization’s An Organization’s Electronic Library of FILESElectronic Library of FILES

**

6.6.77

FILE ORGANIZATIONFILE ORGANIZATION

• ENTITY:ENTITY: Person, Place, Thing, Event Person, Place, Thing, Event about Which Data Must be Keptabout Which Data Must be Kept

• ATTRIBUTE:ATTRIBUTE: Description of a Description of a Particular ENTITYParticular ENTITY

• KEY FIELD:KEY FIELD: Field Used to Retrieve, Field Used to Retrieve, Update, Sort RECORDUpdate, Sort RECORD

**

6.6.88

KEY FIELDKEY FIELD

Field in Each RecordField in Each Record

Uniquely Identifies THIS RecordUniquely Identifies THIS Record

For For RETRIEVALRETRIEVAL

UPDATINGUPDATING

SORTINGSORTING

**

6.6.99

SEQUENTIAL VS. DIRECTSEQUENTIAL VS. DIRECTFILE ORGANIZATIONFILE ORGANIZATION

• SEQUENTIAL:SEQUENTIAL: Tape Oriented; One Tape Oriented; One File Follows Another; Follows File Follows Another; Follows Physical SequencePhysical Sequence

• DIRECT:DIRECT: Disk Oriented; Can be Disk Oriented; Can be Accessed Without Regard to Accessed Without Regard to Physical SequencePhysical Sequence

**

6.6.1010

FILING METHODSFILING METHODS• INDEXED SEQUENTIAL ACCESS METHODINDEXED SEQUENTIAL ACCESS METHOD (ISAM)(ISAM) : :

– EACH RECORD IDENTIFIED BY KEYEACH RECORD IDENTIFIED BY KEY

– GROUPED IN BLOCKS AND CYLINDERSGROUPED IN BLOCKS AND CYLINDERS

– KEYS IN INDEXKEYS IN INDEX

• VIRTUAL STORAGE ACCESS METHODVIRTUAL STORAGE ACCESS METHOD (VSAM)(VSAM) : :– MEMORY DIVIDED INTO AREAS & INTERVALSMEMORY DIVIDED INTO AREAS & INTERVALS

– DYNAMIC FILE SPACE DYNAMIC FILE SPACE

VSAM WIDELY USED FOR RELATIONAL VSAM WIDELY USED FOR RELATIONAL DATABASESDATABASES

• DIRECT FILE ACCESS METHODDIRECT FILE ACCESS METHOD

**

6.6.1111

DIRECT FILE ACCESS METHODDIRECT FILE ACCESS METHOD

• EACH RECORD HAS KEY FIELDEACH RECORD HAS KEY FIELD

• KEY FIELD FED INTO TRANSFORM KEY FIELD FED INTO TRANSFORM ALGORITHMALGORITHM

• ALGORITHM GENERATES ALGORITHM GENERATES PHYSICAL STORAGE LOCATION OF PHYSICAL STORAGE LOCATION OF RECORD (RECORD ADDRESS)RECORD (RECORD ADDRESS)

**

6.6.1212

• DATA REDUNDANCYDATA REDUNDANCY• PROGRAM / DATA DEPENDENCYPROGRAM / DATA DEPENDENCY• LACK OF FLEXIBILITYLACK OF FLEXIBILITY• POOR SECURITYPOOR SECURITY• LACK OF DATA LACK OF DATA SHARING SHARING

& & AVAILABILITYAVAILABILITY

**

TRADITIONAL FILE TRADITIONAL FILE ENVIRONMENT (FLAT FILE)ENVIRONMENT (FLAT FILE)

6.6.1313

DATABASEDATABASE

ORGANIZATION’S ELECTRONIC ORGANIZATION’S ELECTRONIC LIBRARYLIBRARY

STORES & MANAGES DATASTORES & MANAGES DATA

IN A CONVENIENT FORMIN A CONVENIENT FORM

**

6.6.1414

DATABASE MANAGEMENT DATABASE MANAGEMENT SYSTEM (DBMS)SYSTEM (DBMS)

SOFTWARE TO CREATE & MAINTAIN SOFTWARE TO CREATE & MAINTAIN DATA DATA

ENABLES BUSINESS APPLICATIONS ENABLES BUSINESS APPLICATIONS TO EXTRACT DATA TO EXTRACT DATA

INDEPENDENT OF SPECIFIC INDEPENDENT OF SPECIFIC COMPUTER PROGRAMS COMPUTER PROGRAMS

**

DBMS

6.6.1515

COMPONENTS OF DBMS:COMPONENTS OF DBMS:

• DATA DEFINITION LANGUAGE:DATA DEFINITION LANGUAGE:– Defines data elements in databaseDefines data elements in database

• DATA MANIPULATION LANGUAGE:DATA MANIPULATION LANGUAGE:– Manipulates data for applicationsManipulates data for applications

• DATA DICTIONARY:DATA DICTIONARY:– Formal definitions of all variables in Formal definitions of all variables in

database; controls variety of database database; controls variety of database contentscontents

**DBM

S

6.6.1616

STRUCTURED QUERY STRUCTURED QUERY LANGUAGE (SQL)LANGUAGE (SQL)

EMERGING STANDARD EMERGING STANDARD

DATA MANIPULATION LANGUAGEDATA MANIPULATION LANGUAGE

FOR RELATIONAL DATABASESFOR RELATIONAL DATABASES

**

DBMS

6.6.1717

TWO VIEWS OF DATATWO VIEWS OF DATA

BIT

BYTE

FIELD

RECORD

FILE

DATABASE

• PHYSICAL VIEW:PHYSICAL VIEW: Where is data physically?Where is data physically?

– DRIVE, DISK, SURFACE, TRACK, SECTOR DRIVE, DISK, SURFACE, TRACK, SECTOR (BLOCK), RECORD(BLOCK), RECORD

– TAPE, BLOCK, RECORD NUMBER (KEY)TAPE, BLOCK, RECORD NUMBER (KEY)

• LOGICAL VIEW:LOGICAL VIEW: What data is needed by What data is needed by application?application?

– SUCCESSION OF FACTS NEEDED BY SUCCESSION OF FACTS NEEDED BY APPLICATIONAPPLICATION

– NAME, TYPE, LENGTH OF FIELDNAME, TYPE, LENGTH OF FIELD

**DBM

S

6.6.1818

RELATIONAL DATA MODELRELATIONAL DATA MODEL

• DATA IN TABLE FORMATDATA IN TABLE FORMAT

• RELATION:RELATION: TABLE TABLE

• TUPLE:TUPLE: ROW (RECORD) IN TABLE ROW (RECORD) IN TABLE

• FIELD:FIELD: COLUMN (ATTRIBUTE) IN TABLE COLUMN (ATTRIBUTE) IN TABLE

**HOURS RATE TOTAL

ABLE 40.50$ 10.35$ 419.18$ BAXTER 38.00$ 8.75$ 332.50$

CHEN 42.70$ 9.25$ 394.98$ DENVER 35.90$ 9.50$ 341.05$

6.6.1919

TYPES OR RELATIONSTYPES OR RELATIONS

ONE-TO-ONE: ONE-TO-ONE: STUDENT ID

ONE-TO-MANY:ONE-TO-MANY:CLASS

STUDENTA

STUDENTB

STUDENTC

MANY-TO-MANY:MANY-TO-MANY:

STUDENTA

STUDENTB

STUDENTC

CLASS1

CLASS2

6.6.2020

ROOT

FIRST CHILD

2nd CHILD

RatingsRatings SalarySalary

CompensationCompensation JobJobAssignmentsAssignments

PensionPension InsuranceInsurance HealthHealth

BenefitsBenefits

EmployerEmployer

HIERARCHICAL DATA MODELHIERARCHICAL DATA MODEL

6.6.2121

NETWORK DATA MODELNETWORK DATA MODEL

• VARIATION OF HIERARCHICAL VARIATION OF HIERARCHICAL MODELMODEL

• USEFUL FOR MANY-TO-MANY USEFUL FOR MANY-TO-MANY RELATIONSHIPSRELATIONSHIPS

**

NETWORKA

NETWORKB

NETWORKC

NETWORK1

NETWORK2

6.6.2222

OTHER SYSTEMSOTHER SYSTEMS

• LEGACY SYSTEM:LEGACY SYSTEM: older system older system

• OBJECT-ORIENTED DBMS:OBJECT-ORIENTED DBMS: stores stores data & procedures as objectsdata & procedures as objects

• OBJECT-RELATIONAL DBMS:OBJECT-RELATIONAL DBMS: hybrid hybrid

**

6.6.2323

CREATING A DATABASECREATING A DATABASE

• CONCEPTUAL DESIGNCONCEPTUAL DESIGN

• PHYSICAL DESIGNPHYSICAL DESIGN

**

6.6.2424

CREATING A DATABASECREATING A DATABASECONCEPTUAL DESIGN:CONCEPTUAL DESIGN:• ABSTRACT MODEL, BUSINESS ABSTRACT MODEL, BUSINESS

PERSPECTIVEPERSPECTIVE

• HOW WILL DATA BE GROUPED?HOW WILL DATA BE GROUPED?

• RELATIONSHIPS AMONG ELEMENTSRELATIONSHIPS AMONG ELEMENTS

• ESTABLISH END-USER ESTABLISH END-USER NEEDSNEEDS

**

6.6.2525

CREATING A DATABASECREATING A DATABASEPHYSICAL DESIGN:PHYSICAL DESIGN:• DETAILED MODEL BY DATABASE DETAILED MODEL BY DATABASE

SPECIALISTS SPECIALISTS

• ENTITY-RELATIONSHIP DIAGRAMENTITY-RELATIONSHIP DIAGRAM

• NORMALIZATIONNORMALIZATION

• HARDWARE / HARDWARE / SOFTWARESOFTWARE SPECIFICSPECIFIC

**

6.6.2626

ENTITY- RELATIONSHIP ENTITY- RELATIONSHIP DIAGRAMDIAGRAM

1

1

M

1

ORDER

CAN HAVE

PART

SUPPLIER

CAN HAVE

ORDER: #, DATE, PART #, QUANTITY

PART: #, DESCRIPTION, UNIT PRICE, SUPPLIER #

SUPPLIER: #, NAME, ADDRESS

6.6.2727

NORMALIZATIONNORMALIZATIONPROCESS OF CREATING SMALL DATA PROCESS OF CREATING SMALL DATA

STRUCTURES FROM COMPLEX STRUCTURES FROM COMPLEX GROUPS OF DATAGROUPS OF DATA

EXAMPLES:EXAMPLES:

• ACCOUNTS RECEIVABLEACCOUNTS RECEIVABLE

• PERSONNEL RECORDSPERSONNEL RECORDS

• PAYROLLPAYROLL

**

6.6.2828

DISTRIBUTEDDISTRIBUTED DATABASESDATABASES

• PARTITIONED:PARTITIONED: remote CPUs (connected remote CPUs (connected to host) have files unique to that site, to host) have files unique to that site, e.g., records on local customerse.g., records on local customers

• DUPLICATE:DUPLICATE: each remote CPU has each remote CPU has copies of common files, copies of common files, e.g., layouts for standard e.g., layouts for standard reports reports and formsand forms

**

6.6.2929

DATABASE TRENDSDATABASE TRENDS• MULTIDIMENSIONAL DATA ANALYSIS:MULTIDIMENSIONAL DATA ANALYSIS:

3D (or higher) groupings to 3D (or higher) groupings to store store complex datacomplex data

• HYPERMEDIA:HYPERMEDIA: Nodes contain text, Nodes contain text, graphics, sound, video, graphics, sound, video, programs. organizes programs. organizes data as nodes.data as nodes.

**

6.6.3030

DATABASE TRENDSDATABASE TRENDS• DATA WAREHOUSE:DATA WAREHOUSE: Organization’s Organization’s

electronic library stores consolidated electronic library stores consolidated current & historic data for management current & historic data for management reporting & analysisreporting & analysis

• DATA MART:DATA MART: Small data warehouse for Small data warehouse for special function, e.G., special function, e.G., Focused Focused marketing based marketing based on customer on customer infoinfo

**

6.6.3131

COMPONENTS OF DATA WAREHOUSECOMPONENTS OF DATA WAREHOUSE

INFORMATIONDIRECTORY

INTERNALDATASOURCES

EXTERNALDATASOURCES

OPERATIONAL,HISTORICAL DATA

DATA WAREHOUSE

EXTRACT,TRANSFORM

DATAACCESS &ANALYSIS

QUERIES &REPORTS

OLAP

DATA MINING

6.6.3232

DATABASE TRENDSDATABASE TRENDS

• ON-LINE ANALYTICAL PROCESSING ON-LINE ANALYTICAL PROCESSING (OLAP):(OLAP): ability to manipulate, ability to manipulate, analyze large volumes of data from analyze large volumes of data from multiple perspectivesmultiple perspectives

• LINKING DATABASES TO THE WEBLINKING DATABASES TO THE WEB

**

6.6.3333

ELEMENTS OF DATABASE ELEMENTS OF DATABASE ENVIRONMENTENVIRONMENT

DATABASE MANAGEMENT

SYSTEM

DATA

ADMINISTRATION DATABASETECHNOLOGY & MANAGEMENT

USERS

DATA PLANNING & MODELING

METHODOLOGY

6.6.3434

DATABASE DATABASE ADMINISTRATIONADMINISTRATION

• DEFINES & ORGANIZES DATABASE DEFINES & ORGANIZES DATABASE STRUCTURE AND CONTENTSTRUCTURE AND CONTENT

• DEVELOPS SECURITY PROCEDURESDEVELOPS SECURITY PROCEDURES• DEVELOPS DATABASE DOCUMENTATIONDEVELOPS DATABASE DOCUMENTATION• MAINTAINS DBMSMAINTAINS DBMS

**

6.6.3535

Connect to the INTERNETConnect to the INTERNET

Laudon/Laudon Web site: http://www.prenhall.com/laudon

Additional Internet Resources related to this chapter:http://www.oracle.comnews:comp.databasesnews:comp.databases.theoryhttp://w3.one.net/~jhoffman/sqltut.htmhttp://www.compapp.dcu.ie/databases/welcome.htmlhttp://www.acm.org/sigmodhttp://www.dwinfocenter.org/http://138.87.1.4/DataWarehouse/whselead.html

© 2001 Laudon & Laudon, Essentials of Management Information Systems 4/e

6.6.3636

CHAPTER 6. MANAGING CHAPTER 6. MANAGING DATA RESOURCESDATA RESOURCES