MIS6050 CH1 Database Management

7/21/2019 MIS6050 CH1 Database Management

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Compiled by L. Mutanu

CH1 THE DATABASE ENVIRONMENT

Case Study

A school maintains the following class rosters for each class in a

semester





The schools managers need the datasummarized as above for decisionmaking




CH1 THE DATABASE ENVIRONMENTCH1 THE DATABASE ENVIRONMENT

…and then with the help of a

calculator they prepared the charts

and presented them to the

management.

The process was manual

thus requiring effort, prone to

errors and time consuming!!

Te !"ool u!ed to"aptu#e! te data in

pape# $ile! %


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Having heard of the strengths of Ms excel in data analysis

they converted the data into Ms xcel worsheets andprepared the charts.




"#T…

The process still required effort, was prone to

errors, and time consuming!!

$hy%%




D a t a E n

t r y E r r o r

s… .

V o l u m e o f d a t a …

R e petition…




&olution…

$hen selecting a system factor in…

&. Te o#'ani(ation

Bu!ine!! p#oblem

) . T e t e " n o l o '

y

T e p e # $ o # m a n " e

1. T e

u ! e # !

S * i l l ! a +

a i l a b l e




Traditional 'ile (rocessing

) *ata stored in independent files

) (ro+lems

- *ata redundancy

- ac of data integration - *ata dependence - files, storage

devices, and software are

dependent on each other

- ac of data integrity orstandardi/ation




Limitations of File-Based Approach

) &eparation and isolation of data 0 ach program maintains its

own set of data. #sers of one program may +e unaware ofpotentially useful data held +y other programs.

) *uplication of data 0 &ame data is held +y different programs.$asted space and potentially different values and1or differentformats for the same item.

) *ata dependence 0 'ile structure is defined in the program code.

) 2ncompati+le file formats 0 (rograms are written in differentlanguages, and so cannot easily access each other3s files.

) 'ixed 4ueries1(roliferation of application programs 0 (rogramsare written to satisfy particular functions. Any new requirementneeds a new program.





*ata+ase Management Approach) *ata+ase 0 &hared collection of logically related data 5and a

description of this data6, designed to meet the information needs ofan organi/ation.

) *ata+ase Management &ystems 0 A software system that ena+lesusers to define, create, and maintain the data+ase and that providescontrolled access to this data+ase.





*"M& Ma7or 'unctions





8. *ata+ase 9reation

) #se *"M& software development tools todevelop custom application programs

) *ata Manipulation anguage 5*M6





:. *ata+ase Maintenance

) #pdating data+ase to reflect new +usinesstransactions such as a new sale

) *one +y transaction processing systems with

support of *"M&





;. *ata+ase #se

) nd users use a *"M& +y asing for informationvia a query or a report generator

) 4uery language - immediate responses to ad

hoc data requests) <eport generator - quicly specify a report

format for information you want printed in a

report





ntities, Attri+utes and 2nstances

MEMBER

MemberNumber Member Name

TelephoneNumber

1012 Isobel Ringer 293847

1034 John Silver 142536

1056 Fred Flintstone 817263

1097 Annette Kirton 384756



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he !e"ber entity is

the #hole t$ble

MEMBER


TelephoneNumber







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he !e"ber entity

is the #hole t$ble

MEMBER


TelephoneNumber





%$&h &ol'"n stores one

attribute( e)g) !e"ber *$"e




Compiled by L Mutanu



he !e"ber entity

is the #hole t$ble

MEMBER


TelephoneNumber





%$&h &ol'"n stores one

attribute( e)g) !e"ber *$"e

%$&h ro# stores one

instance( e)g) !e"ber 1034




Compiled by L Mutanu


*ata+ase &tructures

) Hierarchical

) =etwor

) <elational

) >+7ect0oriented) Multidimensional





Hierarchical &tructure

) arly *"M& structure) <ecords arranged in tree0lie structure

) <elationships are one0to0many





=etwor &tructure

) #sed in some mainframe *"M& pacages

) Many0to0many relationships





<elational &tructure

) Most widely used structure) *ata elements are viewed as +eing stored in ta+les

) <ow represents record

) 9olumn represents field

)9an relate data in one file with data in another file if +oth files sharea common data element





>+7ect0oriented &tructure) >+7ect consists of

- *ata values descri+ing theattri+utes of an entity

- >perations that can +e

performed on the data

) ncapsulation

- 9om+ine data and operations

) 2nheritance

- =ew o+7ects can +e created

+y replicated some or all of

the characteristics

of parent o+7ects





Multidimensional &tructure

) ?ariation of relational model) #ses multidimensional structures to organi/e

data

) *ata elements are viewed as +eing in cu+es) (opular for analytical data+ases that support

>nline Analytical (rocessing 5>A(6





valuation of *ata+ase &tructures

) Hierarchical - $ored for structured routine transaction processing

- 9an3t handle many0to0many relationships

) =etwor

- More flexi+le than hierarchical

- #na+le to handle ad hoc requests

) <elational

- asily respond to ad hoc requests - asier to wor with and maintain

- =ot as efficient or quic as hierarchical or networ





Advantages of DBMSs

) 9ontrol of data redundancy

) *ata consistency

) &haring of data

) 2mproved security

) conomy of scale

) 9omplexity) &i/e) 9ost of *"M&) Additional hardware costs

) 9ost of conversion) (erformance) Higher impact of a failure

Disadvantages of DBMSs





) (ersonal data+ases

) $orgroup data+ases 0 *epartmental1divisionaldata+ases

) nterprise data+ase - <(s @ *ata $arehouses

) $e+0ena+led

Types of data+ases

CH1 THE DATABASE ENVIRONMENTPersonal Database




Personal Database




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Workgroup database




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Enterprise Database

) nterprise <esource (lanning 5<(6 - 2ntegrate all enterprise functions 5manufacturing, finance, sales,

mareting, inventory, accounting, human resources6

) *ata $arehouse

- 2ntegrated decision support system derived from various

operational data+ases





Web-Enabled Databases

) $e+ applications requiring data+ases

- 09ommerce

- lectronic data interchange 5*26

- (rivate intranets

) 2ssues to consider

- $hich technologies to use%

- &ecurity1privacy protection

- Managing huge volumes of data from 2nternet transactions

- Maintaining data quality

MIS6050 CH1 Database Management

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