8. 8.managingdataresources managingdataresources 8.1

8.8.MANAGINGMANAGING

DATADATARESOURCESRESOURCES



8.1

INFORMATION SYSTEMINFORMATION SYSTEM

INFORMATION INFORMATION

SYSTEMSYSTEM

BUSINESS BUSINESS

CHALLENGECHALLENGE

BUSINESS BUSINESS

SOLUTIONSSOLUTIONS

MANAGEMENTMANAGEMENT

INFORMATIONINFORMATION

TECHNOLOGYTECHNOLOGY

ORGANIZATIONORGANIZATION

8.2

OBSTACLES TO DATABASE OBSTACLES TO DATABASE ENVIRONMENTENVIRONMENT

COST/BENEFIT CONSIDERATIONSCOST/BENEFIT CONSIDERATIONS

PLACING DATA MANAGEMENT PLACING DATA MANAGEMENT FUNCTIONFUNCTION

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

**8.3


• 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

**

8.4


• 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

**

8.5

KEY FIELDKEY FIELD

• Field in Each RecordField in Each Record

• Uniquely Identifies THIS RecordUniquely Identifies THIS Record

• For For RETRIEVALRETRIEVAL

UPDATINGUPDATING

SORTINGSORTING

**

8.6

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

**

8.7

FILING FILING METHODSMETHODS• INDEXED SEQUENTIAL ACCESS METHOD INDEXED 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 METHOD VIRTUAL STORAGE ACCESS METHOD (VSAM)(VSAM)::– MEMORY DIVIDED INTO AREAS & INTERVALSMEMORY DIVIDED INTO AREAS & INTERVALS

– DYNAMIC FILE SPACE DYNAMIC FILE SPACE

VSAM WIDELY USED FOR VSAM WIDELY USED FOR RELATIONALRELATIONAL DATABASESDATABASES

• DIRECT FILE ACCESS METHODDIRECT FILE ACCESS METHOD

**

8.8

DIRECT FILE ACCESS METHODDIRECT FILE ACCESS METHOD

• EACH RECORD HAS EACH RECORD HAS KEY FIELDKEY FIELD

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

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

8.9

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

• DATA REDUNDANCYDATA REDUNDANCY

• PROGRAM / DATA DEPENDENCYPROGRAM / DATA DEPENDENCY

• LACK OF FLEXIBILITYLACK OF FLEXIBILITY

• POOR SECURITYPOOR SECURITY

• LACK OF DATA SHARING & LACK OF DATA SHARING & AVAILABILITYAVAILABILITY

**

8.10

DATABASEDATABASE

• ORGANIZATION’S ELECTRONIC ORGANIZATION’S ELECTRONIC LIBRARYLIBRARY

• STORES & MANAGES DATASTORES & MANAGES DATA

• IN A CONVENIENT FORMIN A CONVENIENT FORM

**

8.11

DATABASE MANAGEMENT SYSTEM DATABASE MANAGEMENT SYSTEM (DBMS)(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

**

8.12 DBMS

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

**8.13 DBM

S

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

EMERGING STANDARD EMERGING STANDARD

DATA MANIPULATION LANGUAGEDATA MANIPULATION LANGUAGE

FOR RELATIONAL DATABASESFOR RELATIONAL DATABASES

**

8.14

TWO VIEWS OF TWO VIEWS OF DATADATABITBIT

BYTEBYTE

FIELDFIELD

RECORDRECORD

FILEFILE

DATABASEDATABASE

• PHYSICAL VIEWPHYSICAL 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

**8.15

ADVANTAGES OF DBMS:ADVANTAGES OF DBMS:

• REDUCES COMPLEXITYREDUCES COMPLEXITY

• REDUCES DATA REDUNDANCY / REDUCES DATA REDUNDANCY / INCONSISTENCYINCONSISTENCY

• CENTRAL CONTROL OF DATA CENTRAL CONTROL OF DATA CREATION / DEFINITIONSCREATION / DEFINITIONS

• REDUCES PROGRAM / DATA REDUCES PROGRAM / DATA DEPENDENCEDEPENDENCE

**8.16 DBM

S

ADVANTAGES OF DBMS:ADVANTAGES OF DBMS:

• REDUCES DEVELOPMENT / REDUCES DEVELOPMENT / MAINTENANCE COSTSMAINTENANCE COSTS

• ENHANCES SYSTEM FLEXIBILITYENHANCES SYSTEM FLEXIBILITY

• INCREASES ACCESS / INCREASES ACCESS / AVAILABILITY OF INFORMATIONAVAILABILITY OF INFORMATION

**

8.17 DBMS

HIERARCHICAL DATABASEHIERARCHICAL DATABASE

ROOT

FIRST CHILD

2nd CHILD

RatingsRatings SalarySalary

CompensationCompensation JobJobAssignmentsAssignments

PensionPension InsuranceInsurance HealthHealth

BenefitsBenefits

EmployerEmployer

8.18

POINTERPOINTER

• FIELD IN ONE RECORD IS ADDRESS FIELD IN ONE RECORD IS ADDRESS OF NEXT RECORD IN SEQUENCEOF NEXT RECORD IN SEQUENCE

POINTER

POINTER

POINTER

8.19

TYPES OR TYPES OR RELATIONSRELATIONS

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

8.20

NETWORK DATA MODELNETWORK DATA MODEL

• VARIATION OF HIERARCHICAL VARIATION OF HIERARCHICAL MODELMODEL

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

**

8.21STUDENT

ASTUDENT

BSTUDENT

C

CLASS1

CLASS2

RELATIONAL DATA MODELRELATIONAL DATA MODEL

• DATA IN TABLE FORMATDATA IN TABLE FORMAT

• RELATION: TABLERELATION: TABLE

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

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

**HOURS RATE TOTALABLE 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$ 8.22

COMPARISON OF DATABASE ALTERNATIVESCOMPARISON OF DATABASE ALTERNATIVES

HIERARCHICAL:HIERARCHICAL:

PROCESSING EFFICIENCY: PROCESSING EFFICIENCY: HIGHHIGH

FLEXIBILITY: FLEXIBILITY: LOWLOW

USER FRIENDLY: USER FRIENDLY: LOWLOW

PROGRAM COMPLEXITY: PROGRAM COMPLEXITY: HIGHHIGH

**

8.23


NETWORK:NETWORK:

PROCESSING EFFICIENCY: PROCESSING EFFICIENCY: MEDIUM / HIGHMEDIUM / HIGH

FLEXIBILITY: FLEXIBILITY: LOW / MEDIUMLOW / MEDIUM

USER FRIENDLY: USER FRIENDLY: LOW / MODERATELOW / MODERATE

PROGRAM COMPLEXITY: PROGRAM COMPLEXITY: HIGHHIGH

**

8.24


RELATIONAL:RELATIONAL:

PROCESSING EFFICIENCY: PROCESSING EFFICIENCY: LOW BUT IMPROVINGLOW BUT IMPROVING

FLEXIBILITY: FLEXIBILITY: HIGHHIGH

USER FRIENDLY: USER FRIENDLY: HIGHHIGH

PROGRAM COMPLEXITY: PROGRAM COMPLEXITY: LOWLOW

**

8.25

CREATING A DATABASECREATING A DATABASE

• CONCEPTUAL DESIGNCONCEPTUAL DESIGN

• PHYSICAL DESIGNPHYSICAL DESIGN

**

8.26

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 RELATIONSHIPS AMONG ELEMENTSELEMENTS

• ESTABLISH END-USER NEEDSESTABLISH END-USER NEEDS

**

8.27

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 / SOFTWARE SPECIFICHARDWARE / SOFTWARE SPECIFIC

**

8.28

ENTITY-RELATIONSHIP DIAGRAMENTITY-RELATIONSHIP DIAGRAM

1

1

1

M

1

ORDER

CAN HAVE

PART

SUPPLIER

CAN HAVE

ORDER: #, DATE, PART #, QUANTITY

PART: #, DESCRIPTION, UNIT PRICE, SUPPLIER #

SUPPLIER: #, NAME, ADDRESS8.29

NORMALIZATIONNORMALIZATION

PROCESS OF CREATING SMALL PROCESS OF CREATING SMALL DATA STRUCTURES FROM DATA STRUCTURES FROM COMPLEX GROUPS OF DATACOMPLEX GROUPS OF DATA

EXAMPLES:EXAMPLES:

• ACCOUNTS RECEIVABLEACCOUNTS RECEIVABLE

• PERSONNEL RECORDSPERSONNEL RECORDS

• PAYROLLPAYROLL

8.30

DATABASE TRENDSDATABASE TRENDS

• DISTRIBUTED PROCESSING: Multiple DISTRIBUTED PROCESSING: Multiple Geographical / Functional Systems Geographical / Functional Systems Connected with NetworkConnected with Network

• DISTRIBUTED DATABASE: Data DISTRIBUTED DATABASE: Data Physically Stored in more than one Physically Stored in more than one LocationLocation– PARTITIONEDPARTITIONED– DUPLICATEDUPLICATE

**8.31


• OBJECT- ORIENTED: Data and OBJECT- ORIENTED: Data and Procedures Stored Together; can be Procedures Stored Together; can be Retrieved, SharedRetrieved, Shared

• HYPERMEDIA: Nodes Contain Text, HYPERMEDIA: Nodes Contain Text, Graphics, Sound, Video, Programs. Graphics, Sound, Video, Programs. Organizes Data as Nodes.Organizes Data as Nodes.

• MULTIDIMENSIONAL: 3D (or higher) MULTIDIMENSIONAL: 3D (or higher) Groupings to Store Complex DataGroupings to Store Complex Data

**8.32


• DATA WAREHOUSE: Organization’s DATA WAREHOUSE: Organization’s Electronic Library Stores Electronic Library Stores Consolidated Current & Historic Data Consolidated Current & Historic Data for Management Reporting & for Management Reporting & AnalysisAnalysis

**

8.33

DATABASE ADMINISTRATIONDATABASE ADMINISTRATION

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

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

**

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8.35

8. 8.managingdataresources managingdataresources 8.1

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