Data Management Data Management OptionsOptions

Dr. Merle P. MartinDr. Merle P. MartinMIS DepartmentMIS DepartmentCSU Sacramento CSU Sacramento

AcknowledgmentsAcknowledgments Dr. Russell ChingDr. Russell Ching ( (MIS DeptMIS Dept) )

Source Materiel / GraphicsSource Materiel / Graphics Edie SchmidtEdie Schmidt ( (UMSUMS) - Graphic Design) - Graphic Design Prentice Hall PublishingPrentice Hall Publishing (Permissions) (Permissions)

Martin, Martin, Analysis and Design ofAnalysis and Design of Business Information SystemsBusiness Information Systems, 1995, 1995

AgendaAgenda Why manage data?Why manage data? DefinitionsDefinitions Typical problemsTypical problems Data AdministratorData Administrator The DBMSThe DBMS Distributing dataDistributing data

Why Manage Data?Why Manage Data? Delayed output Delayed output

((paycheckpaycheck)) Locate a resourceLocate a resource

Where is the stock Where is the stock item stored?item stored?

Where does the Where does the employee work?employee work?

Why Manage Data? Why Manage Data? Make resource decisionsMake resource decisions

Should we turn account Should we turn account over to collection agency? over to collection agency?

Should we send customer Should we send customer letter asking why he / she letter asking why he / she hasn’t shopped here in 6 months?hasn’t shopped here in 6 months?

Should we give employee overtime?Should we give employee overtime?

Why Manage Data? Why Manage Data? Determine resource statusDetermine resource status

Is there enough stock in Is there enough stock in warehouse to satisfy this warehouse to satisfy this customer’s order?customer’s order?

How much should I order?How much should I order? What is the value of What is the value of

this resource?this resource? balance sheetbalance sheet

DefinitionsDefinitions File: resource inventory:File: resource inventory:

MaterialMaterial PeoplePeople

Employees, customersEmployees, customers FundsFunds

Customer balancesCustomer balances Accounts PayableAccounts Payable

Definitions Definitions Data OrganizationData Organization

Bit / byteBit / byte CharacterCharacter FieldField RecordRecord FileFile DBMSDBMS

Data Hierarchy for Data Hierarchy for Stereos to GoStereos to Go

12345 Smith John A 123 Main Street Sacramento CA 9581912345 Smith John A 123 Main Street Sacramento CA 9581912345 Smith John A 123 Main Street Sacramento CA 95819

Smith

DatabaseDatabase

FileFile

RecordRecord

1011001110110011

FieldField

CharacterCharacter(Byte)(Byte)

BitBit 11

{{

Definitions Definitions Views:Views:

Physical - how storedPhysical - how stored Logical - how viewed Logical - how viewed

and usedand used Volatility: - % records that changeVolatility: - % records that change Immediacy: rapidity of changeImmediacy: rapidity of change

Storage ProblemsStorage Problems RedundancyRedundancy AccuracyAccuracy SecuritySecurity Lack of data sharingLack of data sharing Report inflexibilityReport inflexibility Inconsistent data definitions Inconsistent data definitions Too much dataToo much data

information overloadinformation overload

Data AdministratorData Administrator Clean up data definitionsClean up data definitions Control shared dataControl shared data Manage distributed dataManage distributed data Maintain data qualityMaintain data quality

Clean Up DefinitionsClean Up Definitions Synonyms / aliasesSynonyms / aliases Standard data definitions Standard data definitions

names and formatsnames and formats Date of Birth (Date of Birth (AJISAJIS))

mm/dd/yy (mm/dd/yy (courtscourts)) dd/mm/yy (dd/mm/yy (correctionscorrections))

Data DictionaryData Dictionary COBOLCOBOL

Control Shared DataControl Shared Data Local - used by one unitLocal - used by one unit Shared - used by two Shared - used by two

or more activities or more activities Impact of proposed program Impact of proposed program

changes on shared datachanges on shared data Program-to-data element matrixProgram-to-data element matrix Control or clearinghouse?Control or clearinghouse?

Manage Distributed Manage Distributed DataData Geographically dispersedGeographically dispersed

whether shared data whether shared data or notor not

Different levels of detailDifferent levels of detail different management levelsdifferent management levels

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StrategicStrategicPlanningPlanning

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Maintain Data QualityMaintain Data Quality Put owners in charge Put owners in charge

of dataof data verify data accuracy verify data accuracy

and qualityand quality Fairbanks Court exampleFairbanks Court example

Who owns the data?Who owns the data?

IssueIssueShould the Data Should the Data

Administrator control Administrator control ALLALL data, data,

or just that data that crosses or just that data that crosses organizational boundaries?organizational boundaries?

WHAT DO YOU THINK?WHAT DO YOU THINK?

The DBMSThe DBMSData Base Management Data Base Management

System: software that System: software that permits a firm to:permits a firm to: centralizecentralize data data managemanage them efficiently them efficiently provide provide accessaccess to applicationsto applications

such as payroll, inventorysuch as payroll, inventory

DBMS ComponentsDBMS Components Data Design Data Design

Language (Language (DDL)DDL) Data Manipulation Data Manipulation

Language (Language (DMLDML)) Inquiry Language (Inquiry Language (IQLIQL)) Teleprocessing Interface (Teleprocessing Interface (TPTP)) Martin, Figure 16-5Martin, Figure 16-5

DatabaseDatabaseDatabaseDatabase

TeleprocessTeleprocessTeleprocessTeleprocess

InterfaceInterfaceInterfaceInterface

DesignersDesignersDesignersDesigners

DDLDDLDDLDDL

End-UsersEnd-UsersEnd-UsersEnd-Users

UpdateUpdate Retrieve RetrieveUpdateUpdate Retrieve Retrieve

IQLIQLIQLIQL

ProgrammersProgrammersProgrammersProgrammers

Applic. SoftwareApplic. SoftwareApplic. SoftwareApplic. Software

DMLDMLDMLDML

IQL LANGUAGEIQL LANGUAGE

IQLIQLSELECT EMP-ID,SELECT EMP-ID, EMP-FIRST-EMP-FIRST-

NAME,NAME, EMP-LAST-EMP-LAST-

NAME,NAME, EMP-YTD-PAYEMP-YTD-PAY FROM FROM

EMPLOYEEEMPLOYEE WHERE EMP-WHERE EMP-

ID=1234ID=1234..

DataDataBaseBase

3-level Database Model3-level Database Model James MartinJames Martin Sprague / McNurlin, Sprague / McNurlin,

Fig. 7-2, pg. 207 Fig. 7-2, pg. 207

External Level (1)External Level (1) User views (User views (logical)logical) By application programBy application program Each has unique viewEach has unique view Schema / subschemaSchema / subschema

Schema and SubschemasSchema and Subschemas

DBMS

Schema

Subschema Subschema

Physical DatabasePhysical Database

DBMS SoftwareDBMS Software

Overall View of the DataOverall View of the DataIndividual

ViewsIndividual Views

User User User User User User

Subschema

Enterprise Level (2)Enterprise Level (2) Under control of Data Under control of Data

AdministratorAdministrator DBMSDBMS Implementation data removedImplementation data removed

passwordspasswords report viewsreport views

Physical Level (3)Physical Level (3) SchemaSchema Pointers Pointers

((e.g., next recorde.g., next record)) Flags Flags

((e.g., record frozene.g., record frozen))

Traditional Data Traditional Data Models Models Hierarchical - one parentHierarchical - one parent NetworkNetwork

more than one parentmore than one parent student to course, majorstudent to course, major

Relational (Relational (tables)tables)

Hierarchical ModelHierarchical Model

11

Dept. ADept. A Dept. BDept. B Dept CDept C

Project 1Project 1

EmployeesEmployees

33 5522 44 66

Network ModelNetwork Model

John SmithJohn SmithJohn SmithJohn Smith

SavingsSavingsSavingsSavings

CheckingCheckingCheckingChecking

MortgageMortgageMortgageMortgage

Jane SmithJane SmithJane SmithJane Smith

RelationalRelational

Order Number Order Date Account Number Date Shipped

Account Number Last NameFirst Name Credit LimitMiddle Initial . . .

Product Code Product Name UnitPrice Manufacturer Code

Order Number Line Item Number Product Code Quantity

Manufacturer NameManufacturer Code

CustomerCustomer

OrdersOrders

Line ItemsLine Items

ProductsProducts

Manufac(turer)Manufac(turer)

Object-oriented DBMSObject-oriented DBMSAn object is:An object is:

a piece of data a piece of data PLUSPLUS procedures performed procedures performed

on data on data PLUSPLUS attributes describing data attributes describing data

PLUSPLUS relationship between object relationship between object

and other objectsand other objects

Distributed DataDistributed Data Goals:Goals:

move processing as move processing as close to users as possibleclose to users as possible

allow several applications to run allow several applications to run simultaneously on same datasimultaneously on same data

Distributed TypesDistributed Types FragmentedFragmented

distribute data without distribute data without duplicationduplication

users unaware of users unaware of where data locatedwhere data located

SegmentedSegmented data duplicated data duplicated one site has master fileone site has master file problem with problem with data synchronizationdata synchronization

Why Distribute?Why Distribute? Save moneySave money

offload DB processes offload DB processes to less expensive to less expensive machines (PCs) machines (PCs)

Lower telecommunications costsLower telecommunications costs DB closer to usersDB closer to users

Decrease dependence on a single Decrease dependence on a single computer manufacturercomputer manufacturer

Why Distribute Why Distribute Move control closer Move control closer

to ownerto owner Increased DBMS scopeIncreased DBMS scope

more varied types of datamore varied types of data link at workstationslink at workstations

Permit storage of multimedia dataPermit storage of multimedia data

True Distributed DBTrue Distributed DB Local autonomy Local autonomy

((ownershipownership)) No reliance on central siteNo reliance on central site Continuous operationsContinuous operations

not affected by another sitenot affected by another site Data transparencyData transparency IndependenceIndependence

IndependenceIndependence FragmentationFragmentation ReplicationReplication HardwareHardware SoftwareSoftware NetworksNetworks DatabaseDatabase

Problems With Problems With Distributed DatabasesDistributed Databases SecuritySecurity Shared dataShared data

simultaneous updatesimultaneous update ComplexityComplexity Need telecommunications Need telecommunications

infrastructureinfrastructure

IssueIssueIs data in your organization Is data in your organization

totallytotally distributed? distributed? How?How? Should it be?Should it be? Why or why not?Why or why not?

Points to rememberPoints to remember DefinitionDefinition Typical problemsTypical problems Role of Data AdministratorRole of Data Administrator The DBMSThe DBMS Distributing dataDistributing data