mis thepowerofit

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The Power of ITSurvival Guide for the CIO

Jan De Sutter


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The Power of IT Survival Guide for the CIO_____________________________________________________________________________________________________

Cover Design Don WeigandCartoons Ted GoffWeb site http://www.the-power-of-it.com

Copyright 2!-2" #y Jan De Sutter $ %&& right' re'er(ed

)o part of thi' wor* 'ha&& #e reproduced+ 'tored in a retrie(a& 'y'tem+ or tran'mitted #y any mean'+ e&ectronic+mechanica&+ photocopying+ recording or otherwi'e+ without permi''ion from the author. )o patent &ia#i&ity i'a''umed with re'pect to the u'e of the information contained herein. ,(ery rea'ona#&e effort ha' #een made tore'pect the copyright' of other per'on' or entitie'. %ny#ody who #e&ie(e' that hi' or her copyright' ha(e #eeninfringed i' in(ited to contact the author 'o that the nece''ary arrangement' can #e ta*en.

%&& term' mentioned in thi' wor* that are *nown to #e trademar*' ha(e #een appropriate&y capita&ied. Theauthor cannot atte't the accuracy of thi' information. 'e of a term in thi' wor* 'hou&d not #e regarded a'affecting the (a&idity of any trademar*.

%&though e(ery precaution ha' #een ta*en in the preparation of thi' wor*+ the author a''ume' no re'pon'i#i&ityfor error' or omi''ion'. ,(ery effort ha' #een made to ma*e thi' wor* a' comp&ete and a' accurate a' po''i#&e+

#ut no warranty of fitne'' i' imp&ied. The information pro(ided i' on an a' i'0 #a'i'. The author 'ha&& ha(eneither &ia#i&ity nor re'pon'i#i&ity to any per'on or entity with re'pect to any &o'' or damage' ari'ing from theinformation contained in thi' wor*. Thi' wor* ref&ect' the per'ona& opinion' of the author and doe' in no wayengage hi' current or pre(iou' emp&oyer'.

1i#rary of Congre'' Contro& )um#er: 2"!3!!4u#&i'her: 5oo*Surge+ 11C

)orth Char&e'ton+ South Caro&ina

6S5): -78"73-93-2

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AcknowledgementsFirst Edition

6 wou&d &i*e to than* 4rofe''or Car&o' De 5ac*er ;ni(er'ity of %ntwerp< and4rofe''or ,ddy =an Di>c* ;ni(er'ity of 5ru''e&'< for their thorough editing+ he&pfu&'ugge'tion' and thoughtfu& comment'.

%&'o+ a pro>ect of thi' magnitude re?uire' the 'upport of co&&eague' and friend'. 6addre'' a 'pecia& word of gratefu&ne'' for Dir* Don' and )ia&& @ABiggin'+ who ga(eu'efu& ad(ice on the pure&y technica& matter'.

ina&&y+ thi' wor* cou&d not #e po''i#&e without the &o(e and in'piration of my wife 1utand my chi&dren arie*e and Jaco#. Than* you for #eing thereE

Second Edition

6 recei(ed many 'pontaneou' reaction' from my on&ine reader' and wi'h to than* themfor that. %&& their remar*' ha(e #een ta*en into account.

6 a&'o had the occa'ion to pre'ent thi' #oo* in (ariou' internationa& conference' and am(ery gratefu& to the organiation' that a&&owed me to do 'o. During the'e conference' 6had many eFchange' with my pu#&ic who ga(e 'ome (ery u'efu& feed#ac* on the #oo*and it' content.

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To my mother. May she rest in peace.

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Table of Contents

INTRODCTION!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"

Information Technology.....................................................................................................................2

The changing role of IT......................................................................................................................3volution of the IT Indu!try................................................................................................................"

#$out thi! $oo%................................................................................................................................&

Online 'e!ource!..............................................................................................................................(IT management magazines and newsletters......................................................................................9IT Business Analysts......................................................................................................................9

IT News sites................................................................................................................................9

)urther 'eading..............................................................................................................................*+

INFRASTRCTRE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!""

Introduction...................................................................................................................................*2

Com,uting -ardware.......................................................................................................................*

Computers.................................................................................................................................14

Digital technology........................................................................................................................1

The !on Neumann Architecture.....................................................................................................19

Central "rocessing #nit................................................................................................................$%

&ain &emory..............................................................................................................................$1

Internal 'uses.............................................................................................................................$$

Input()utput..............................................................................................................................$*O,erating Sy!tem!..........................................................................................................................3+O,erating Sy!tem!..........................................................................................................................3+

"urpose o+ an )perating ,ystem....................................................................................................*%,tructure o+ an )perating ,ystem..................................................................................................*%

Characteristics o+ )perating ,ystems.............................................................................................*1Autonomic Computing..................................................................................................................*$

,ecurity.....................................................................................................................................*$/ocal Service!.................................................................................................................................3

,toring Data...............................................................................................................................*4-ile ,ystems...............................................................................................................................*4

elational Data'ase &anagement ,ystems /DB&,s0......................................................................*)'2ect3)riented Data'ase &anagement ,ystems /))DB&,0.............................................................4%

)'2ect3elational Data'ase &anagement ,ystems /)DB&,0...........................................................41

Benchmaring o+ DB&,s...............................................................................................................4*

0etwor%ing Service!........................................................................................................................"The ),I e+erence &odel.............................................................................................................4

The Internet protocols..................................................................................................................45

"hysical 6ayer.............................................................................................................................47

Data lin layer............................................................................................................................4

Networ layer.............................................................................................................................7

Transport layer...........................................................................................................................5$

Application layer..........................................................................................................................5*

,ecurity.....................................................................................................................................5

1iddleware.....................................................................................................................................&(

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Basic &iddleware ,er!ices............................................................................................................59

Ad!anced &iddleware ,er!ices......................................................................................................7%

&iddleware Technologies..............................................................................................................7*

Application -ramewors...............................................................................................................74

Application ,er!ers...................................................................................................................... 7

e!t Practice!.................................................................................................................................

Automate your asset management................................................................................................ 77

Automate your systems management............................................................................................77A!oid ,ingle "oints o+ -ailure........................................................................................................7

Centralise your client management................................................................................................79

Consolidate and rationalize continuously.........................................................................................79

8eep control o!er your architecture...............................................................................................%

8eep your in+rastructure scala'le...................................................................................................%

"rinting also deser!es a strategy...................................................................................................$

econsider your storage strategy..................................................................................................*

ely on open standards 'ut don:t 'e stu''orn................................................................................4

,tandardize as much as you can....................................................................................................

#se the right tools.......................................................................................................................

Online 'e!ource!............................................................................................................................4

)urther 'eading..............................................................................................................................4(

INFOR#ATION S$STE#S!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!%"

Information Sy!tem!.......................................................................................................................(2)perational and In+ormational ,ystems..........................................................................................94

Production......................................................................................................................................("

;ord "rocessors..........................................................................................................................9

,preadsheets..............................................................................................................................97

Drawing tools..............................................................................................................................97

Computer Aided Design and &anu+acturing /CAD(CA&0....................................................................9

roupware systems........................................................................117

Characteristics o+ >roupware ,ystems..........................................................................................119Bene+its o+ >roupware ,ystems...................................................................................................1$%

"otential riss o+ >roupware ,ystems...........................................................................................1$%

u!ine!! Proce!! Su,,ort...............................................................................................................*2*

?nterprise Application Integration /?AI0........................................................................................1$*

?@changing in+ormation with other organizations...........................................................................1$7

?3commerce.............................................................................................................................1*%

Characteristics o+ Business "rocess ,upport ,ystems......................................................................1*4

Bene+its o+ Business "rocess ,upport ,ystems...............................................................................1*4

iss Business "rocess ,upport ,ystems......................................................................................1*4

Tactic!.........................................................................................................................................*3"

&etrics.....................................................................................................................................1*

Benchmaring...........................................................................................................................1*5Acti!ity Based Costing................................................................................................................1*7

Data warehousing......................................................................................................................1*7Characteristics o+ Tactical In+ormation ,ystems.............................................................................14$

Bene+its o+ Tactical In+ormation ,ystems......................................................................................14*iss o+ Tactical In+ormation ,ystems..........................................................................................14*

Strategy.......................................................................................................................................*Balanced ,corecards..................................................................................................................144

Data mining..............................................................................................................................145;e' -arming............................................................................................................................147

Characteristics o+ ,trategic In+ormation ,ystems...........................................................................14Bene+its o+ ,trategic In+ormation ,ystems.....................................................................................14

e!t Practice!...............................................................................................................................*(

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Budget +or hardware e!ery year..................................................................................................$*$

Buy your systems F2ust in timeG...................................................................................................$**

>ood enough can 'e 'est...........................................................................................................$*4

In!est to reduce TC).................................................................................................................$*4

6in the pro2ect e@penses to the o'2ecti!es...................................................................................$*

&anage your so+tware assets care+ully..........................................................................................$*

)nly go +or win3win situations.....................................................................................................$*5

"ush +or eual treatment o+ the IT 'udget.....................................................................................$*5etire your old IT systems in time...............................................................................................$*5

,et up pre3 and post3implementation metrics................................................................................$*7

,tart +rom the 'ene+its not the costs...........................................................................................$*7

Online 'e!ource!...........................................................................................................................234

)urther 'eading............................................................................................................................23(

PROCESSES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!)+"

Introduction..................................................................................................................................22u!ine!! Proce!!e!........................................................................................................................2

Typology..................................................................................................................................$44Huality and Huality &anagement.................................................................................................$49

u!ine!! Proce!! 'eengineering......................................................................................................2"3ow to succeed a change pro2ect.................................................................................................$

The relationship 'etween Business Change and IT.........................................................................$

IT Proce!!e!.................................................................................................................................2"&IT ,er!ice &anagement /IT,&0...................................................................................................$5

e!t Practice!...............................................................................................................................2&3

Apply the sel+3ser!ice concept where possi'le................................................................................$5*

Build generic solutions................................................................................................................$5*

Create a uni+ied !iew o+ the 'usiness o'2ects.................................................................................$54

&ae lightweight In+ormation ,ystems.........................................................................................$54

Online 'e!ource!...........................................................................................................................2&&

)urther 'eading............................................................................................................................2&

PRO,ECTS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!)-%

Introduction..................................................................................................................................2+

Software /ife Cycle........................................................................................................................23

/ife Cycle 1odelling.......................................................................................................................2

Code and -i@.............................................................................................................................$74

;ater+all &odel.........................................................................................................................$74The Incremental &odel...............................................................................................................$75The ,piral &odel........................................................................................................................$77

Time 'o@ing..............................................................................................................................$77Agile ,o+tware De!elopment.......................................................................................................$79

)ther models............................................................................................................................$1Conce,t 6,loration.......................................................................................................................242

'e7uirement!...............................................................................................................................243Pro8ect Initiation............................................................................................................................24"

"ro2ect ?stimation......................................................................................................................$9e!ign.........................................................................................................................................2(

"rocess oriented modelling..........................................................................................................$94Data oriented modelling.............................................................................................................$9

)'2ect )riented &odelling...........................................................................................................$9

Im,lementation............................................................................................................................3+2

"rogramming languages.............................................................................................................*%$,o+tware reuse..........................................................................................................................*%9

Computer Aided ,o+tware ?ngineering /CA,?0 tools.......................................................................*1%

Integrated De!elopment ?n!ironments /ID?s0...............................................................................*11

Pro8ect 1onitoring and Control........................................................................................................3*3

>antt Charts.............................................................................................................................*1*

"ro2ect ?!aluation and e!iew Techniue(Critical "ath &ethod /"?T(C"&0.......................................*14

Critical Chain ,cheduling and Bu++er management..........................................................................*15

:erification and :alidation...............................................................................................................3*(

;hite Bo@ testing......................................................................................................................*19

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#nit Testing..............................................................................................................................*$1

Blac Bo@ testing.......................................................................................................................*$1

Integration Testing....................................................................................................................*$$

,ystem Testing.........................................................................................................................*$$

egression testing.....................................................................................................................*$$

Alpha and Beta Testing...............................................................................................................*$*

Automated testing.....................................................................................................................*$*

Test "lan..................................................................................................................................*$*Test esults..............................................................................................................................*$4

Software ;uality 1anagement.........................................................................................................32"

Capa'ility &aturity &odel /C&&0..................................................................................................*$

I,)39%%1.................................................................................................................................*$5

TicIT......................................................................................................................................*$7

,o+tware "rocess Impro!ement and Capa'ility d?termination /,"IC?0..............................................*$7

Software Configuration 1anagement................................................................................................32(

9ocumentation 9evelo,ment..........................................................................................................33*

Training........................................................................................................................................332

In!tallation...................................................................................................................................333

1aintenance.................................................................................................................................33"

Typology..................................................................................................................................**

"ro'lems associated with maintenance.........................................................................................**

&etrics.....................................................................................................................................**7

Application &ining......................................................................................................................**

'etirement...................................................................................................................................33(

/egal con!ideration!......................................................................................................................3+Intellectual "roperty...................................................................................................................*4%

e!t Practice!...............................................................................................................................3"Aim +or Conceptual Integrity.......................................................................................................*4

Design Twice Code )nce............................................................................................................*45Do not 'e a+raid o+ riss.............................................................................................................*45

Do not re3in!ent the wheel.........................................................................................................*45?@pect the une@pected...............................................................................................................*47

-it the methodology to the pro2ect not the other way around..........................................................*47a!e an )pen ,ource strategy....................................................................................................*4

In!ol!e the users.......................................................................................................................*46imit the size o+ the pro2ect teams...............................................................................................*49

&anage the reuirements...........................................................................................................*%

Not all de!elopers are created eual.............................................................................................*%

)rganize the re+actoring process..................................................................................................*1an pro2ect elements up +ront....................................................................................................*1

emem'er Broo:s 6aw..............................................................................................................*1

,eparate concerns.....................................................................................................................*$

,eparate sta'le and unsta'le elements.........................................................................................*$

,eparate Transaction "rocessing and Analytical "rocessing..............................................................**

Tae care o+ the installation process.............................................................................................**

Thin Big de!elop small.............................................................................................................**

#se the right tool +or the 2o'.......................................................................................................*4

Online 'e!ource!...........................................................................................................................3""

)urther 'eading............................................................................................................................3"&

OR.ANI/ATION!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!0-0

Introduction..................................................................................................................................3&)rganization.............................................................................................................................*54

)'2ects in the organizational model..............................................................................................*51anagement.................................................................................................................................3&4

&apping &anagers to )rganizational #nits....................................................................................*5&anagerial acti!ities and roles.....................................................................................................*5

Organi


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;or Teams..............................................................................................................................*77

Organieographical organization...........................................................................................................*1

&i@ed structures........................................................................................................................*$)rganization o+ pro2ects..............................................................................................................**

Organi


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1E$OND T&E &$PE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!++0

The future and IT..........................................................................................................................

Online 'e!ource!...........................................................................................................................)urther 'eading............................................................................................................................4

.(OSSAR$!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!++%

Online Glo!!arie!...........................................................................................................................43

INDE2!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!+3'

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Fig. 6.4$ 4roce'' Iua&ityFig. 6.5 - 6T61Fig. 7.1$ 4o'ition of 4ro>ect' in the 6T 'tac*Fig. 7.2$ Waterfa&& ode&Fig. 7.3$ 6ncrementa& ode&

Fig. 7.4$ 4ro>ect e'timationFig. 7.5$ S%/SDFig. 7.6$ ,ntity He&ation'hip DiagramFig. 7.7$ C&a'' diagramFig. 7.8$ Se?uence diagramFig. 7.9$ State diagramFig. 7.10$ "G1 programmingFig. 7.11$ Gantt chartFig. 7.12$ 4,HT/C4Fig. 7.13$ 6ntegration of ta'*'Fig. 7.14$ Cyc&omatic comp&eFity

Fig. 7.15$ 5athtu# diagramFig. 7.16$ Compari'on of methodo&ogie'Fig. 7.17$ Communication pro#&em'Fig. 8.1$ 4o'ition of organiation in the 6T 'tac*Fig. 8.2$ %cti(itie'+ 4roce''e'+ unction' and 4ro>ect'Fig. 8.3$ @rganiationa& 'u#unit'Fig. 8.4$ Coordination mechani'm'Fig. 8.5$ @rganiationa& form'Fig. 8.6$ unctiona& @rganiationFig. 8.7$ 4roce''-@riented @rganiationFig. 8.8$ 4roduct-oriented @rganiationFig. 8.9$ Geographica& @rganiationFig. 8.10$ iFed @rganiationFig. 8.11$ Coordination of 4ro>ect #y the unctiona& anager'Fig. 8.12$ Coordination of 4ro>ect #y a 4ro>ect anagerFig. 8.13$ Wea* atriF @rganiationFig. 8.14$ 5a&anced atriF @rganiationFig. 8.15$ Strong atriF @rganiationFig. 8.16$ CoeFi'tence of centra&ied and decentra&ied 6TFig. 9.1$ 4o'ition of Strategy in the 6T 'tac*Fig. 9.2$ Strategic %&ignment ode&

Fig. 9.3$ unctiona& 6ntegrationFig. 9.4$ 5a&anced ScorecardFig. 9.5$ KachmannL' ramewor*Fig. 9.6- Co't @ptimiationFig. 9.7$ Gartner Group Bype Cur(eFig. 9.8$ 5o'ton/6T mode&Fig. 9.9$ Comp&eFity

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Fig 9.10- GartnerA' agic Iuadrant

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(ist of Tables

Table 2.1- Storage %rchitecture 'trength' and wea*ne''e'Table 2.2$ 6,,, 92.! 'tandard'Table 3.1$ Categoriation of GroupwareTable 3.2 - JS4 and %S4Table 3.3$ BT1 and 1Table 4.1$ 5enefit' of Te&ewor*ingTable 5.1 Co't type' and co't e&ement'Table 5.2$Co'ting ('. 5udgeting

Table 5.3$ DepreciationTable 5.4$ 4ay#ac* periodTable 5.5 )et 4re'ent =a&ueTable 5.6$ Deci'ion CriteriaTable 6.1$ 6mpro(ement ('. 6nno(ationTable 7.1$ 1ife cyc&e mode&ingTable 7.2$ unction point' to 1ine' of code con(er'ionTable 7.3$ Co't dri(er'Table 7.4$ The 4,HS Co't Dri(erTable 7.5$ Compari'on of programming &anguage' generation'Table 7.6$ Cyc&omatic Comp&eFity and Hi'*

Table 7.7$ 5enefit' of CTable 8.1$ anageria& %cti(itie' and Ho&e'Table 8.2$ Mnow&edge of 6T Staff per profi&eTable 8.3$ S*i&&' and per'ona&ity of 6T 'taff per profi&eTable 9.1$ 5a&anced 6T 'corecard

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"Introd4ction

FComputer ,cience is no more a'out computers than astronomy is a'out telescopes. F/?. ;. Di2stra0


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Information Technolog5

EIn 1% a'out nine out o+ 1% worers made and mo!ed thingsJ today that is down to one out o+ +i!e.

The other +our are nowledge people or ser!ice worers.E

/"eter Drucer0

%ccording to 4rofe''or Hu''e&& %c*off NO+ the content of the human mind can #ec&a''ified into fi(e categorie':

Data$ 'ym#o&'. Data i' rawP it 'imp&y eFi't' and ha' no 'ignificance #eyond it'

eFi'tence. 6t can eFi't in any form+ u'a#&e or not. 6t doe' not ha(e meaning ofit'e&f. or eFamp&e+ a 'pread'heet genera&&y 'tart' out #y ho&ding data.

Information- data that i' proce''ed to #e u'efu&. %n'wer' to QwhoQ+ QwhatQ+

QwhereQ+ and QwhenQ ?ue'tion'. 6nformation i' data that ha' #een gi(en meaning#y way of re&ationa& connection. Thi' QmeaningQ can #e u'efu&+ #ut doe' notha(e to #e. or eFamp&e+ a re&ationa& data#a'e ma*e' for information from thedata 'tored within it.

Knowledge- app&ication of data and information. %n'wer' the QhowQ ?ue'tionP

Mnow&edge i' the appropriate co&&ection of informationP 'uch that itL' intent i' to#e u'efu&. o't of the 6nformation 'y'tem' we u'e eFerci'e 'ome type of 'tored*now&edge ;the #u'ine'' ru&e'


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Introduction_____________________________________________________________________________________________________

The changing role of IT

,ar&y computer' $ mainframe' - were too &arge and eFpen'i(e to ha(e #road app&icationin #u'ine''. 6n the 8'+ they #ecame co't-effecti(e and wide&y adopted and 'tandard'

and &anguage' were de(e&oped 'pecifica&&y for #u'ine'' u'e. 6nitia&&y+ though+ themainframe had a pure&y 'upporting ro&e+ mo't&y in the accounting department. Thi' wa'the era of!lectronic Data "rocessing (!D".

6n the #eginning of the 89' 65 introduced the fir't"ersonal Comp#ter ;"C< andpu#&i'hed the technica& detai&' of thi' machine. Thi' opened the po''i#i&ity for othercompanie' to ma*e I$M compatible computer' and cheap c&one'. 6ndi(idua&' u'edthe'e machine' in their home en(ironment #ut 'oon they infi&trated in the office' and onthe production f&oor'. %t fir't+ the ,D4 profe''iona&' did not *now how to cope withthi' e(ent. Some thought it wa' >u't hype that wou&d di'appear a' fa't a' it came+ other''imp&y ignored it and 'ome #egan a war again't the'e intruder'. %fter a whi&e+ it #ecame

c&ear that the 4C wa' there to 'tay. 6t had con?uered it' p&ace in the organiationP fir't a'a 'tand-a&one wor*'tation+ #ut rapid&y the need to act a' a termina& for the mainframearo'e.

% few year' &ater+ two other e(o&ution' too* p&ace: departmental comp#tersand%ocal&rea 'etwors (%&'s. The'e techno&ogie' a&&owed peop&e to 'hare information andwor* together in 'ma&& wor*group' or company wide. The'e e(o&ution' had anothereffect: where the good o&d ,D4 department on&y had one Qc&ientQ within theorganiation+ the new&y #orn 6T department 'udden&y had to cope with the who&eorganiation. %&mo't e(ery white-co&&ar or #&ue-co&&ar emp&oyee had a 4C connected to

the networ*. Where the u'er' of traditiona& ,D4 were 'pecia&i't' in their #ranch andwere therefore we&& trained to wor* with the'e 'y'tem'+ the newcomer' on&y had a&imited *now&edge of computer'. Specia&ied 'er(ice' &i*e training c&a''e' and he&pde'*' had to #e organied #y the 6T department.

5ecau'e of the impro(ed producti(ity of the emp&oyee' and #ecau'e of the new way' tocommunicate and wor* together+ the traditiona& hierarchie' within the organiation'#egan to fa&& apart. Term' &i*e flat organi)ations and hori)ontal departments #ecamecommon. %&'o+ and thi' i' an important i''ue+ the dependency of 6T increa'eddramatica&&y. 6nformation Techno&ogy 'upported a&mo't e(ery part of the #u'ine''. %'6T co(ered more and more facet' of the #u'ine''+ it wa' more and more u'ed to get a

#etter in'ight in the #u'ine''.Management Information *ystems+$#siness Intelligence+Data Wareho#sing and Data Mining #ecame part of the norma& (oca#u&ary of the#u'ine'' manager'.

eanwhi&e+ another techno&ogica& e(o&ution too* p&ace: the digita&iation ofte&ecommunication'. 4eop&e and their computer' 'tarted to >oin force' o(er networ*'

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Introduction_____________________________________________________________________________________________________

and the ana&og communication techno&ogy wa' digitied. 5ecau'e of thi' techno&ogica&con(ergence many organiation' too* the deci'ion to put communication' under the'ame per'on who wa' in charge of the data proce''ing #u'ine''.

Today+ 6T i' c&o'e to or e(en part

of the core b#siness in manyorganiation'. Thi' i' the ca'e in'er(ice organiation' ;#an*ing+in'urance+ pu#&i'hing+go(ernment...< who'enonmateria& product' cannot eFi'twithout 6T. Thin* of a 'imp&e#an* account: thi' i' a pure&yimaginary o#>ect without anyphy'ica& manife'tationP it on&yeFi't' on the di'*' and in the

memorie' of the #an*L'computer'. The modern 'toc*eFchange i' another eFamp&eP a&&the tran'action' are mere&y #it'and #yte' f&oating around in the

networ*' of the 'toc*#ro*er' and again no phy'ica& eFchange' ta*e p&ace. 6n manyorganiation'+ thi' i' ref&ected #y the pre'ence of a repre'entati(e in the 'eniormanagement team: the Chief Information +fficer (CI+. The C6@ i' in charge of #othtechno&ogy manager' and #u'ine'' manager' and i' the &in* #etween the'e two. 6n otherorganiation'+ where 6T i' mere&y a 'upport function+ theIT Managerp&ay' hi' ro&e a'the &ine manager of a techno&ogica&&y oriented department.


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Introduction_____________________________________________________________________________________________________

E6ol4tion of the IT Ind4str5

The 6T indu'try i' an eFtreme&y (aried 'ector of the economy+ inc&uding thou'and' of'ma&&+ medium-'ied and #ig companie' 'er(ing many different mar*et'. @ne way of

&oo*ing at it i' to di'tingui'h three 'egment'+ centered on hardware+ software, andservices. nti& the 89'+ the'e three 'egment' were 'tructured vertically. Cu'tomer''e&ected an 6T 'o&ution from a few (endor'+ 'uch a' 65+ D,C+ or Wang. The'ede&i(ered comp&ete 'o&ution'+ inc&uding hardware+ 'oftware and the ad>oining 'er(ice'.5ecau'e of the proprietary nature of the'e 'o&ution'+ cu'tomer' were tied to their'upp&ier' and there were few opportunitie' &eft for other (endor' to offercomp&ementary product' or 'er(ice'. Two e(ent' &ed to a fundamenta& change in thi''ituation: &ow co't microproce''or' and open 'oftware 'tandard'. The'e e(ent'tran'formed the 6T indu'tryP (endor' #ecame 'pecia&ied in hardware+ 'oftware or'er(ice'. 6n e(ery 'egment+ many competing or comp&ementary product' eFi't+ a&&comp&ying with a &imited num#er of 'tandard'.

The 6T indu'try i' current&y one of the mo't dynamic in the g&o#a& economy. %' a'ector+ it not on&y create' mi&&ion' of high-&e(e& >o#' #ut it a&'o he&p' other organiation'to #e more efficient and effecti(e and it 'timu&ate' inno(ation. The importance of 6T i'not 'o much the growth of it' 'hare of the tota& economy #ut in the change' that areintroduced in the organiation' that u'e and a''imi&ate it.

Hecent e(ent' 'eem to #e 'howing that a new e(o&ution i' going on. % tremendou''ha*eout i' now ta*ing p&ace in which 'ma&&er (endor' are ta*en o(er #y the #ig p&ayer'who are now comp&eting their portfo&io with comp&ementary product' and 'er(ice'. 6t

&oo*' a' if the pendu&um i' 'winging #ac* in the other direction and we can eFpect new$ e(en more 'e(ere $ (endor &oc*-in'. To #e watched (ery carefu&&y #y the deci'ionma*er'E

"


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Abo4t this book

6T i' not >u't a#out computer'P it connect' at &ea't eight different domain' 'tac*ed uponeach other a' #ui&ding #&oc*':

Fig. 1.1$Domains of IT

Thi' framewor* wi&& 'er(e a' the 'tructure of thi' #oo*. ,(ery chapter wi&& di'cu'' onedomain in more detai&. Do not eFpect a comprehen'i(e 'ur(ey #ut a management'ummary. @n&y the topic' contri#uting to thi' wor* wi&& #e put in per'pecti(e+ other'wi&& #e >u't mentioned or 'imp&y dropped. Se(era& &in*' to We# 'ite' and good #oo*'wi&& a&&ow the reader to dig deeper in the di'cu''ed item'.

%' thi' #oo* ha' to #e a practica& he&p for the 6T manager+ there wi&& #e an importantpart a#out the #e't practice' in the different domain' of 6T. & best practicei' a po&icy+procedure+ techni?ue+ too&+ or methodthat+ through eFperience and re'earch+ ha' pro(ento &ead re&ia#&y to a good re'u&t. 5e't practice' are a 'ource of competiti(e ad(antage a'they are often the re'u&t of 'ignificant eFperience and co't&y tria& and error. 6n thi' wor*+the'e #e't practice' wi&& aim at four o#>ecti(e': information &i?uidity+ a(ai&a#i&ity+agi&ity+ and co't'.

&


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Information %i-#idity- uch &i*e ca'h &i?uidity+ the &i?uidity of information i' a

mea'ure of #u'ine'' 'ucce''. 6n a 'ucce''fu& organiation+ data f&ow' 'mooth&yand information change' into economic (a&ue. 6nformation &i?uidity i' o#tained#y integration at a&& &e(e&'. 6ntegration 'hou&d #e the dri(ing force #ehindde'ign+ de(e&opment+ and u'e of a&& 6T 'y'tem'.

&vailability- %' mo't organiation' #ecome more and more dependent on 6T+ iti' important to en'ure a(ai&a#i&ity of the 'er(ice'. Thi' doe' not mean that a&& the6T 'y'tem' ha(e to #e f&aw&e'' and fai&'afe. Bowe(er+ good thought ha' to #egi(en to what cou&d #e the outcome' for the organiation if a&& or part of the 6T'er(ice' are temporari&y una(ai&a#&e+ and what can #e done to minimie the'eeffect'.

&gility- 6f there i' one certainty it i' change. The mar*et change' con'tant&y+ 'o

do &egi'&ation and techno&ogy. 4roduct &ife cyc&e' and their time to mar*et aregetting 'horter and 'horter. %' a re'u&t+ 6T ha' to #e agi&e. We can no &ongerafford mono&ith' that co't a fortune to #ui&d and are a&mo't impo''i#&e to

maintain. Cro''-compati#i&ity+ reu'e and &ightweight functiona&ity are the idea'to #e con'idered.

Costs- ,'pecia&&y in time' of economic '&owdown+ the co't' of 6T are under

con'tant 'crutiny. nfortunate&y+ it i' difficu&t to ?uantify the #enefit' of 6T in,uro' or Do&&ar' and it i' meaning&e'' to approach the 6T in(e'tment' too mucha' an accountant. %&'o the non-?uantifia#&e #enefit' for the organiation mu't #econ'idered.

6t i' worth noting that the'e o#>ecti(e' can #e conf&icting: for increa'ing the a(ai&a#i&ity+important in(e'tment' ha(e to #e made+ which conf&ict' with &owering the co't'. @n theother hand+ a c&o'e integration wi&& pro#a#&y get in the way of agi&ity. % good #a&ance

wi&& a&way' #e re?uired and thi' #a&ance wi&& depend on the 'ituation your organiationi' in.

ina&&y+ an eFten'i(e g&o''ary end' the content of thi' #oo*. 6t can #e u'efu& a' a ?uic*reference+ to de#un* the >un*0 in the go##&edygoo* u'ed #y 6T profe''iona&'.


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4


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Online Reso4rces

IT management maga)ines and newsletters

5yte againe - http://www.#yte.comC6@ againe - http://www.cio.comC6@ Wor&dwide - http://www.cio-wor&dwide.comComputer Wor&d - http://www.computerwor&d.com6nfo Wor&d - http://www.infowor&d.comSearchC6@ $ http://www.'earchcio.comKD)et againe - http://www.dnet.com

IT $#siness &nalysts

%#erdeen Group $ http://www.a#erdeen.com5&oor He'earch $ http://www.#&oor.co.u*5o'ton Con'u&ting Group $ http://www.#cg.com5u'ine'' 6nte&&igence $ http://www.#u'inte&.com5ut&er Group $ http://www.#ut&ergroup.co.u*Cam#ridge ar*et 6nte&&igence $ http://www.cmi.co.u*orre'ter He'earch $ http://www.forre'ter.comGartner Group $ http://www.gartner.comBurwit $ http://www.hurwit.com6DC Corp $ http://www.idcre'earch.comBead'trong $ http://www.head'trong.comJupiter He'earch $ http://www.>up.comMi&&en %''ociate' $ http://www.*i&&en.comMnow&edgeStorm $ http://www.*now&edge'torm.cometa Group $ http://www.metagroup.com@= $ http://www.o(um.com4atricia Sey#o&d Group $ http://www.p'group.comStrategic ocu' $ http://www.'trategicfocu'.com

IT 'ews sites

http://dai&ynew'.yahoo.com/head&ine'/tchttp://'&a'hdot.orghttp://www.cnn.com/T,CB/http://www.techwe#.comhttp://www.wired.com/new'/techno&ogy

(


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)Infrastr4ct4re

FI thin there is a world maret +or may'e +i!e computers.G

/Thomas ;atson IB& 194*0

**


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Introd4ction

Infrastr#ct#reencompa''e' a&& permanent faci&itie' that pro(ide 'er(ice' to the higher&ayer'. 6nfra'tructure i' b#siness7#naware. The owner'hip of the infra'tructure &ie' with

the top of the organiation and not with the indi(idua& u'er' or organiationa& entitie'.Thi' i' #ecau'e the importance of the infra'tructure goe' far #eyond the'e indi(idua&intere't' and ha' an inf&uence on the 'trategic capa#i&itie' of the organiation.

Fig. 2.1$"osition of Infrastr#ct#re in the IT stac

ig. 2.2 'how' a more detai&ed #rea*down of the infra'tructure &ayer. %t the #ottomthere i' the Computing Bardware. Ju't one &ayer higher+ the @perating Sy'tem i' thefir't &e(e& of Sy'tem Software that run' and operate' thi' hardware. 1oca& Ser(ice' and)etwor* Ser(ice' ta*e care of the connecti(ity to &oca&&y 'tored data and remote'y'tem'. The idd&eware &ayer $ fina&&y $ hide' the imp&ementation detai&' for the6nformation Sy'tem' 'ituated higher up in the 'tac*.


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Fig. 2.2$%ayers within the IT infrastr#ct#re

*3


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Com74ting &ardware

Comp#ters

=ariou' type' of computer' form the heart of the infra'tructure. 6t i' not ea'y to ma*e agood o(er(iew of the different c&a''e' of computer'. 'ua&&y+ computer' are c&a''ified#y performance and that i' what we wi&& do in thi' o(er(iew.

4er'ona& Computer' ;4C'o#' to and from that 4C. Thi' program run' uno#tru'i(e&y inthe #ac*ground+ ne(er interfering with the routine wor* #eing performed #y that 4C.

ainframe'

% Mainframe (comp#ter i' a &arge and eFpen'i(e computer capa#&e of 'upportinghundred' or e(en thou'and' of c&ient' 'imu&taneou'&y. 6n the hierarchy #a'ed onperformance+ mainframe' are >u't #e&ow 'upercomputer'. The di'tinction #etween 'ma&&mainframe' and #ig minicomputer' i' (ague+ depending rea&&y on how the manufacturerwant' to mar*et it' machine'. Bi'torica&&y+ mainframe' were introduced a' computer'that run admini'trati(e app&ication' 'uch a' accounting and 'toc* management for &argeorganiation'. They are oriented toward' centra&ied computing+ rather than di'tri#utedor networ* computing. Today+ many organiation' 'ti&& re&y on their mainframe' toconduct their #u'ine'': the important in(e'tment' of the pa't ma*e it hard to >u'tify the

*


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TheI*+ 99:;'erie' of 'tandard' co(er' a&mo't a&& eFten'ion' of the 1atin a&pha#et a'we&& a' the Cyri&&ic ;6S@ 9978-7


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Fig. 2.4$ Components of a 0on 'e#mann comp#ter

The (on )eumann computer i' further a#&e to store not on&y it' data and theintermediate re'u&t' of computation+ #ut a&'o tostore the instr#ctions+ that carry out thecomputation.

@#(iou'&y+ the computer' we u'e today are the re'u&t of numerou' impro(ement' of the#a'ic architecture. or eFamp&e+ indeF regi'ter' and genera&-purpo'e regi'ter'+ f&oatingpoint data repre'entation+ indirect addre''ing+ and hardware interrupt'+ input and output+para&&e& eFecution+ (irtua& memory+ and the u'e of mu&tip&e proce''or' ha(e #eenintroduced. Bowe(er+ none of the'e impro(ement' fundamenta&&y changed the origina&

architecture.

Central "rocessing Unit

The Contro& and %rithmetic component of a computer i' grouped together with theHegi'ter' in the Central "rocessing Unit or C"U.The C4 can #e 'een a' the Q#rainQof the computer. Data and in'truction' f&ow #etween the C4 and main memory in #othdirection'. 6n'truction' arri(ing at the C4 are decoded and eFecuted+ and then there'u&t' of the eFecution go #ac* to the memory.

The C4 ha' to #e a#&e to under'tand+ recognie and eFecute certain #a'icprogramming in'truction'. Thi' group of #a'ic in'truction' i' *nown a' the instr#ctionset. %t the &owe't &e(e&+ an in'truction i' a 'e?uence of A' and A' that de'cri#e' aphy'ica& operation the computer i' to perform. Different type' of C4L' ha(e differentin'truction 'et'. 6n other word'+ the #a'ic operation' one C4 can under'tand andeFecute can #e different from that which another C4 can under'tand and eFecute.

2+


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C4' can #e 'u#di(ided into two categorie': H6SC and C6SC.1I*C'tand' for1ed#cedInstr#ction *et Comp#teri.e.+ the C4 under'tand' on&y a reduced 'et of in'truction'.CI*C'tand' for Comple8 Instr#ction *et Comp#ter+ a term that repre'ent' the tendencyto #ui&d e(er &arger and more comp&eF in'truction 'et'+ imp&ying that an e(er-increa'ingamount of comp&eFity i' inc&uded in the hardware architecture. Since it wa' a''umed

that 'i&icon techno&ogy wou&d reach it' phy'ica& &imit'+ re'earcher' #egan to ?ue'tionwhether thi' wa' rea&&y the #e't approach to ta*e. The 'urpri'ing re'u&t of their re'earchwa' that on&y 'ome 2U of the in'truction' were fre?uent&y u'ed. Thi' &ed to the idea ofa reduced in'truction 'et. %nother ad(antage of the H6SC approach wa' that it #ecame'ignificant&y ea'ier for the C4 to proce'' mu&tip&e in'truction' in para&&e&. Today+near&y a&& the ma>or computer manufacturer' offer computer' with the H6SCarchitecture.

icroproce''or'

% microprocessor i' a computer who'e entire C4 i' contained on one IntegratedCirc#it (IC.The fir't commercia& microproce''or wa' the 6nte& ""+ which appearedin 83. Thi' chip wa' ca&&ed a "-#it microproce''or 'ince it proce''ed on&y four #it' ofdata at a time. % 'ing&e chip microproce''or today inc&ude' other component' 'uch a'memory+ memory management+ cache'+ f&oating-point unit'+ input/output port'+ andtimer'. 6t ha' reduced the computer to a 'ma&& and ea'i&y rep&acea#&e de'ign component.

6n 87 Gordon oore+ co-founder of6nte&+ o#'er(ed that each new memorychip contained rough&y twice a' muchcapacity a' it' predece''or and wa'

re&ea'ed within 9-2" month' of thepre(iou' chip. So+ if thi' trend continued+computing power wou&d ri'eeFponentia&&y with time. Thi' o#'er(ationi' common&y *nown a' Moore


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Main Memory

F54%8 should 'e enough +or any'ody.G

/Bill >ates 1910

The ear&y mainframe' on&y had a few *i&o#yte' of memory+ made up of 'ma&& ferrite+core-'haped+ e&ement'. 5ac* in the eightie'+ the fir't 4C' were e?uipped with "M ofmemory and the "M that wa' propo'ed #y 5i&& Gate' wa' con'idered to #e more thanenough. Today+ howe(er+ a norma&0 4C ha' three order' of magnitude more memorythan it' ear&y predece''or' and the interna& memory of 'er(er' in mea'ured inGiga#yte'.

6n Dynamic 1andom &ccess Memory ;D1&M information i' 'tored in capacitor'+which can retain energy for a certain time. The'e capacitor' are arranged in a matriF ofrow' and co&umn'. Thi' techno&ogy can #e produced at a &ow co't with high den'itie'.

Theast "age Mode ("Ma(ai&a#&e with 'ome memory modu&e' i' an impro(ementof the 'tandard DH% techno&ogy. With re'pect to 4+!8tended Data +#tp#t (!D+repre'ent' a further de(e&opment. 1i*e 4 and ,D@+ *D1&M (*ynchrono#s D1&Mi' yet another de(e&opment of the memory techno&ogy+ in contra't to 4 or ,D@howe(er+ thi' techno&ogy i' not #ac*ward compati#&e i.e.+ SDH% memory chip' canon&y #e u'ed in computer 'y'tem' that eFp&icit&y 'upport thi' techno&ogy.

*tatic memorychip' operate at a high 'peed+ thi' i' why they are u'ed a' cachememory#etween the main memory and the C4 regi'ter' ;&e(e& 20


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6/@ de(ice'. The C4 u'e' the address b#s to 'e&ect a 'ing&e addre'' at a time toaddre'' either memory or 6/@. The control b#si' u'ed to contro& the operation': dictatethe 'peed of the operation' with the c&oc* 'igna&+ 'how the direction of the data f&ow+ma*e the di'tinction #etween a memory and an 6/@ operation etc.

The fir't"ersonal Comp#ter Interface ("CI#u' had !2 #it' data #u' and a c&oc* rateof !! B. The 4C6 #u' can 'upport a maFimum tran'fer rate of up to !! #p'. The"-#it (er'ion 'upport' a maFimum tran'fer rate of up to 23 #p'. %n importantad(antage of the 4C6 #u' i' that it i' not dependant on the proce''or type. Thu'+ the 4C6#u' can a&'o #e u'ed with non-6nte& proce''or'.

The&ccelerated 5raphics "ort (&5"i' an indi(idua& graphic' card '&ot de(e&oped #y6nte&. The %G4 concept a&&ow' the graphic' card to acce'' direct&y data 'tored in themain memory. The main-#oard chip 'et and %G4 eFchange the data at B !2 #it'at a time+ which corre'pond' with a tran'fer rate of 2 5/'. 6n addition+ the %G4 card'upport' the 'o-ca&&ed F2 mode or F" mode+ which gi(e a dou#&ed or ?uadrup&ed 'peed.

%G4 i' downward compati#&e with 4C6.

The 4C card interface i' a 'tandard for credit-card 'ied eFpan'ion card'+ which wa'e'ta#&i'hed #y the "ersonal Comp#ter Memory Card Interface &ssociation ("CMCI&in 88. The fir't product' that u'ed thi' 'tandard were memory card'. The 'tandardwa' gradua&&y eFpanded 'o other hardware cou&d #e de'igned and u'ed in accordancewith the 4C Card 'tandard+ 'uch a' interface card'+ modem'+ and 1%) adapter'. 6tcome' in three type' ;6+ 66+ and 666< with different thic*ne''.

The &ate't de(e&opment of the 4C Card 'tandard i' the Card$#s.Thi' #u' ha' certainimpro(ement' 'uch a' reduced power con'umption+ #etter compati#i&ity+ and higherperformance. The 4C Card5u' 'pecification de'cri#e' a !2-#it #u' 'imi&ar to 4C6+ with#u' ma'ter capa#i&ity and a fre?uency of !! B with tran'fer rate' up to !2 5/'.Thi' a&&ow' note#oo*' to u'e thi' modern #u' with more 'ophi'ticated hardware+ whichre?uire' higher 6/@ performance' ;e.g.+ a't ,thernetu't commoditie'. Therefore it ha'#een decided to &imit the di'cu''ion in thi' 'ection to the periphera& #u'e' and theimportant topic of ma'' 'torage.

4eriphera& #u'e'

23


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The connection of periphera& de(ice' 'uch a' di'* array'+ tape dri(e'+ printer'+ and'canner' to computer' i' done u'ing 'tandardied interface'. The 'imp&e't one' are the;'eria&< HS2!2 interface and the ;para&&e&< Centronic' interface+ #ut o(er the year' moree&a#orate 'o&ution' ha(e emerged.

The Universal *erial $#s (U*$i' a periphera& #u' 'tandard de(e&oped #y indu'try&eader'+ e&iminating the need to in'ta&& card' into dedicated computer '&ot' andreconfigure the 'y'tem ;ig. 2.7


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Fig. 2.5$ U*$ connectors

There are different 'ucce''i(e SCS6 'tandard'+ which are #ac*ward' compati#&e. Thi'mean' that+ if you attach an o&der de(ice to a newer computer with 'upport for a &ater

'tandard+ the de(ice wi&& wor* at the '&ower data rate. % wide&y u'ed SCS6 'tandard i'&tra-2 which u'e' a " B c&oc* rate to get maFimum data tran'fer rate' up to 95p'. 6t pro(ide' a greater maFimum ca#&ing di'tance ;up to 2 meter';? serialb#s i' the indu'try-'tandard imp&ementation of %pp&e Computer+ 6nc.L' digita& 6/@'y'tem+ *nown a' ireWire. 6tL' a (er'ati&e+ high-'peed+ &ow-co't method ofinterconnecting a (ariety of 4er'ona& Computer periphera&' and con'umer e&ectronic'de(ice'. De(e&oped #y the indu'tryL' &eading techno&ogy companie'+ the 'pecification

2"


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wa' accepted a' a 'tandard #y the 6,,, Standard' 5oard in 887+ with 'ucce''i(ere(i'ion' 'ince then. 6,,, !8" ha' #een adopted #y the con'umer e&ectronic' indu'tryand pro(ide' a 4&ug-and 4&ay-compati#&e eFpan'ion interface for the 4C. The #p'+ 2 #p'+ and " #p' tran'fer rate' current&y 'pecified in 6,,, 4!8".a andthe propo'ed enhancement' in 6,,, 4!8".# are we&& 'uited to mu&ti-'treaming 6/@

re?uirement'. The 'tandard a&&ow' the connection of up to ! de(ice'+ without the needfor additiona& hardwareP a&& you need i' a f&eFi#&e 'iF-wire ca#&e.

The!nhanced "arallel "ort (!""and the!8tended Capabilities "ort (!C"are twomodern para&&e& port 'tandard' that 'upport #i-directiona& communication with eFterna&de(ice'. They are a#out ten time' fa'ter than the o&der Centronic' 'tandard.

Data Storage

Data 'torage can #e di(ided into three categorie': primary+ 'econdary+ and tertiary data

'torage.

Primar5 Data Storage

%part from the proce''or 'peed and the 'ie of the computerL' main memory+ theperformance of the primary data storagei' the mo't important factor for a computerL're'pon'e time. Thi' i' data 'torage that can random&y acce'' the data. Bard di'* dri(e'are the de(ice' u'ed for mo't 'tandard app&ication'.

The access timei' ca&cu&ated from the time re?uired for mu&tip&e 'e?uentia& proce''e'.When a program want' to read or write data+ the @perating Sy'tem generate' a re?ue't

that i' pa''ed to the hard di'* contro&&er. Thi' re?ue't cau'e' the dri(e to po'ition theread/write head' at a point on the di'* 'urface. Thi' time i' ca&&ed the see time, thetime re?uired for the head mechani'm to tra(e& acro'' the di'*. The settling time'pecifie' how &ong the head mechani'm re?uire' to re't mechanica&&y after a headmo(ement for o'ci&&ation' to #e eFtingui'hed. 6f the read/write head i' po'itioned on thecorrect trac*+ it mu't wait unti& the de'ired #&oc* i' reached. Thi' wait time i' ca&&edlatency or rotational wait time. Thi' figure i' eFc&u'i(e&y dependent on the di'*L'rotationa& 'peed. %t thi' point the di'*L' ;interna&< transfer rate#ecome' important. 6t'how' the num#er of #yte' tran'ferred per 'econd. The higher a di'*L' tran'fer rate+ thefewer tran'fer time i' re?uired for the data tran'fer. @nce the data ha' arri(ed at the harddi'* contro&&er+ it i' then 'ent (ia the periphera& #u' to the computerA' main memory.

% way to increa'e performance i' dis caching. Di'* caching wor*' on the 'ameprincip&e a' memory caching+ #ut in'tead of u'ing high-'peed SH%+ con(entiona&memory i' u'ed. % copy of a part of the di'* i' he&d in an intermediate memory #&oc*.Smart a&gorithm' are u'ed to determine which part' ha(e to #e *ept in memory+ 'o thatthe pro#a#i&ity of ha(ing the data a(ai&a#&e in the cache i' high ;'ometime' up to 8U


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%nother intere'ting con'truction i' the1ed#ndant &rray of Ine8pensive Diss (1&ID.%' the name imp&ie' it i' a way of 'toring the 'ame data in different p&ace' ;thu'+redundant&y< on mu&tip&e hard di'*'. 5y p&acing data on mu&tip&e di'*'+ 6/@ operation'can o(er&ap in a #a&anced way+ impro(ing performance. Since mu&tip&e di'*' increa'etheMean Time between ail#re;MT$


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changer' that contain a CD recorder there i' a co't-effecti(e way to archi(e and #ac*upin 'ma&& or medium-'ied networ*'.

CD71W- Thi' i' a techno&ogy that a&&ow' a medium to #e written to repeated&y. The'edri(e' can a&'o write a 'ing&e data 'e''ion to CD-H media.

M#ltiread- Thi' 'pecification define' the guide&ine' nece''ary for optica& de(ice' to #ecapa#&e of reading di'c' created in CD format'. %ny de(ice adhering to the'pecification i' capa#&e for reading audio CD+ CD-H@+ CD-H+ and CD-HW.

D0D- With pre''ure from the (ideo indu'try+ a new optica& techno&ogy emerged withDigital 0ersatile Dis;D0D


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Infra!tructure_____________________________________________________________________________________________________

Storage )etwor*ing

% 'tudy carried out in 2 #y the ni(er'ity of 5er*e&ey 'howed that 8!U ofinformation created today i' in digita& form. %&'o+ (irtua&&y a&& data ha' #ecome mi''ion-critica&. %' a re'u&t+ the need to add more 'torage+ 'er(ice more cu'tomer' and #ac*-up

more data ha' #ecome a difficu&t ta'*. Today+ Direct &ttached *torage (D&*i' 'ti&& themo't common 'torage architecture in u'e+ #ut )%S and S%) are gaining an increa'edmar*et 'hare % *torage &rea 'etworor *&'i' a high-'peed 'pecia&-purpo'e networ*;or 'u#-networ*< that interconnect' different *ind' of data 'torage de(ice' witha''ociated data 'er(er'. Thi' i' oppo'ed to the 'etwor &ttached *torage ;'&*u't ca&&ed a database manager+i' a program that &et' one or more u'er' create and acce'' data in a data#a'e. TheD5S manage' re?ue't' from u'er' and program' 'o that they do not ha(e tounder'tand where the data i' phy'ica&&y &ocated. 6n hand&ing re?ue't'+ the D5Sen'ure' the integrityof the data ;that i'+ ma*ing 'ure it continue' to #e acce''i#&e and i'con'i'tent&y organied a' intended< and sec#rity;ma*ing 'ure on&y tho'e with acce''pri(i&ege' can acce'' the data


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%nother ta#&e ho&d' the order' that were ta*en down:

@rderrdD rd)+&D De+rip&i$% )a%&i&

2!"7 2"" 5a'e#a&& G&o(e' 2

2!" 222!8" 5a'*et#a&& !

2!"3 2!" T-'hirt

2!"9 2"" Be&met

2!"8 77!8!7 5icyc&e 8

The co&umn' of a data#a'e ta#&e are *nown a' fields orattrib#tes+ whi&e the row' areca&&ed records. % ey i' a fie&d that identifie' a record. or the Cu'tomer ta#&e+ thecompany name cou&d #e u'ed a' a *ey+ #ut when there are two companie' with the 'amename+ there i' a pro#&em. The #e't way i' to u'e an ar#itrary who&e num#er or a code;Cu't6Doining the two ta#&e' #a'edon thi' re&ation'hip+ we can add fie&d' from #oth ta#&e' and 'ee a&& order' a&ong withany pertinent cu'tomer data.

Data not on&y ha' to #e 'tored+ it a&'o ha' to #e retrie(ed from an HD5S. Thi' i' done#y ?uerie'. % -#ery i' a (iew of data that repre'ent' the data from one or more ta#&e'. 6n

He&ationa& Data#a'e'+ ?uerie' are #ui&t u'ing *tr#ct#red B#ery %ang#age(*B%. SI1inc&ude' the capa#i&ity of manipu&ating #oth the 'tructure of a data#a'e and it' data. 6nit' mo't common form+ SI1 i' u'ed to create a 'imp&e S,1,CT ?uery.

1etL' ta*e the eFamp&e and #ui&d a ?uery to &oo* at cu'tomer order'. BereL' the SI1 forit:

SELECT Name, Description, Quantity

F!" Customer

#$EE Customer%Cust&D = !r'er%!r'Cust&D

!DE () Name, Description

Thi' ?uery 'tart' with the S,1,CT *eyword. S,1,CT 'imp&y mean' that we wi'h toretrie(e record' from the ta#&e'. o&&owing the S,1,CT *eyword i' the &i't of fie&d'.)eFt come' the H@ *eyword. Thi' i' u'ed to 'how where the data i' coming from.Bere+ it i' coming from the Cu'tomer ta#&e and the @rder ta#&e. The WB,H, c&au'e'pecifie' which fie&d' are u'ed to >oin the ta#&e'. Bere we are matching the Cu't6D fie&d

3


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from Cu'tomer to the @rdCu't6D fie&d ;the foreign *ey< in @rder. The @HD,H 5c&au'e 'tate' the way the re'u&t' ha(e to #e ordered ;fir't #y )ame+ then #yDe'cription


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Con'ider the fo&&owing ta#&e:

D r$d)& i& S&a&e rie

888 T-'hirt San Diego Ca&ifornia

8882 5a'e#a&&G&o(e'

San Diego Ca&ifornia

888! T-'hirt e'a %riona 7

888" Be&met 1o' %nge&e' Ca&ifornia 2

888 5a'e#a&&G&o(e'

e'a %riona 7

8883 Be&met 4hoeniF %riona 9

8889 5a'*et#a&& Green =a&&ey %riona 8

8888 5icyc&e Tom#'tone %riona

Tran'formed to the 5C) thi' wou&d re'u&t in three ta#&e':

D r$d)& i&

888 T-'hirt San Diego8882 5a'e#a&&G&o(e'

San Diego

888! T-'hirt e'a

888" Be&met 1o' %nge&e'

888 5a'e#a&&G&o(e'

e'a

8883 Be&met 4hoeniF

8889 5a'*et#a&& Green =a&&ey

8888 5icyc&e Tom#'tone

i& S&a&eSan Diego Ca&ifornia

1o' %nge&e' Ca&ifornia

Tom#'tone %riona

e'a %riona

4hoeniF %riona

Green =a&&ey %riona

i& rie

Tom#'tone

e'a 7

4hoeniF 9Green =a&&ey 8

San Diego

1o' %nge&e' 2

3(


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6ndeFing

Conceptua&&y+ the re&ationa& mode& i' 'imp&e: operation' on a 'et of ta#&e' yie&d anotherta#&e a' the re'u&t. 5ut 'imp&y 'canning ta#&e' i' inefficient+ that i' why inde8eseFi't.6ndeFe' can #e't #e compared with the a&pha#etica& indeF of a #oo*P they are ea'y to

'can and point to occurrence' of the 'earched word in the actua& teFt.

There are different type' of indeFe' #ut the common point i' that they can 'peed up the'earch for a particu&ar row or the 'orting of a 'et of row'. o't data#a'e' ha(e 'ome*ind of -#ery optimi)erthat choo'e' the #e't path to get the data that 'ati'fy a gi(en?uery. %n indeF can 'peed up con'idera#&y >oin'+ @HD,H 5 and GH@4 5 c&au'e'from a S,1,CT 'tatement. 6t can a&'o 'peed up ?uerie' for which the condition' matchthe co&umn' and 'ort order of the indeF. When you ha(e a primary *ey+ you a&readyha(e an imp&icit&y defined uni?ue indeF on the primary *ey co&umn'. 6t i' a good idea todefine non-uni?ue indeFe' on the foreign *ey'.

4ara&&e& data#a'e'

Today+ data#a'e re'earch i' focu'ing on techno&ogy that a&&ow' mu&tip&e+ 'ma&&ermachine' to achie(e the 'ame throughput a' 'ing&e+ &arger machine+ with greater'ca&a#i&ity and re&ia#i&ity. % 'o-ca&&ed parallel D$M*run' acro'' mu&tip&e proce''or'and di'*' and eFecute' operation' in para&&e&+ whene(er po''i#&e+ to impro(eperformance.4ara&&e& data#a'e architecture' can #e #road&y c&a''ified into three categorie': 'hared

memory+ 'hared di'*+ and 'hared nothing. The fir't two architecture' re?uire a 'pecia&hardware arrangementP the &a't one u'e' a 'tandard communication networ*.

The ad(antage' of a para&&e& D5S are o#(iou':

6mpro(ed 4erformanceP

6mpro(ed %(ai&a#i&ityP

6mpro(ed He&ia#i&ityP

1ower Tota& Co't of @wner'hip ;TC@


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The +pen 5ro#pha' formed a Wor*ing Group to pro(ide 'pecification' for a commonSI1&pplication "rogramming Interface (&"Iand a common data#a'e protoco& thatena#&e' D5S from one (endor to communicate direct&y with D5S from another(endor without the need for a gateway.

+bect7+riented Database Management *ystems (++D$M*

He&ationa& data#a'e techno&ogy fai&' to hand&e the need' of comp&eF 6nformationSy'tem'P they re?uire the app&ication de(e&oper to force an information mode& intota#&e' with re&ation'hip' #etween them.

The 'tudy of data#a'e' i' centered on the pro#&em of data modeling. % data mode& i' aco&&ection of we&&-defined concept' that he&p peop&e to con'ider and eFpre'' thepropertie' of data inten'i(e information 'y'tem'.

% data mode& con'i't' of:

*tatic properties'uch a' o#>ect'+ attri#ute' and re&ation'hip'P

Integrity r#leso(er o#>ect' and operation'P

Dynamic properties'uch a' operation' or ru&e' defining new data#a'e 'tate'

#a'ed on app&ied 'tate change'.

He&ationa& data#a'e' are capa#&e of 'upporting the fir't two point' and re&y on 'eparate'oftware program' for defining the dynamic propertie' of the mode&. The di'ad(antage

of de&egating the dynamic propertie' to 'eparate program' i' that they cannot #e app&ieduniform&y in a&& 'cenario' 'ince they are defined out'ide the data#a'e.

@#>ect-oriented data#a'e' can mode& a&& three of the'e point' direct&y within thedata#a'e thu' 'upporting a comp&ete pro#&em/'o&ution mode&&ing capa#i&ity. @#>ect-oriented data#a'e' pro(ide a unifying paradigm that a&&ow' one to integrate a&& threea'pect' of data mode&&ing and to app&y them uniform&y to a&& cu'tomer' of the data#a'e.@@D5S' ha(e+ howe(er+ 'ome draw#ac*' a' we&&. ir't+ there i' no common ?uery&anguage 'uch a' SI1 for the re&ationa& data#a'e'. The performance of @#>ect-orienteddata#a'e' i' much &ower than that of HD5S'. oreo(er+ there i' a &ac* of'tandardied indu'try 'upport+ and fina&&y+ high-tech feature' 'uch a' mu&ti-threading

and para&&e& proce''ing are not a(ai&a#&e.

Today+ there are many companie' mar*eting commercia& o#>ect-oriented data#a'e' thatare 'econd-generation product'. @@D5S' ha(e e'ta#&i'hed them'e&(e' in niche' 'ucha' e-commerce+ engineering+ and 'pecia& purpo'e data#a'e' in area' 'uch a' 'ecuritie'and medicine.

*


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+bect71elational Database Management *ystems (+1D$M*

The re&ationa& data#a'e (endor' con'idered the arri(a& of @@D5S' a' a threat. %' are'u&t they 'tarted to add feature' and functiona&ity to their product' to 'tay competiti(e.Hea&-&ife imp&ementation' of the +bect 1elational Databases (+1D$M*sa' we&& a'theoretica& eFten'ion' of the re&ationa& mode& 'uch a' the Third anife'to0 N"O 'tartedto appear mid 88'.

*tored proced#resare co&&ection' of SI1 'tatement' and f&ow-contro& &anguage that are'tored in a precompi&ed way into the data#a'e. Stored procedure' are 'upported #y mo'tHD5S'+ #ut there i' a fair amount of (ariation in their 'yntaF and capa#i&itie'.Triggersare Stored 4rocedure' that are &aunched on a gi(en e(ent+ 'uch a' in'erting orupdating a row in a ta#&e.

The addition of comp&eF data type' 'uch a'$%+$s ($inary %arge +bectsi' another

eFamp&e of how the re&ationa& data#a'e (endor' ha(e reacted to @@D5S'. % 51@5 i'a &arge #&oc* of data 'tored in a data#a'e+ 'uch a' an image or 'ound fi&e. % 'pecia&'u#type of 51@5 i' C1@5P character' are u'ed in'tead of pure #inary information. %51@5 cannot #e interpreted #y the data#a'e management 'y'tem #ut i' *nown on&y #yit' 'ie and &ocation. odern HD5S' a&&ow for 'ome re&ati(e&y 'imp&e operation' on51@5' 'uch a' 'toring+ retrie(ing+ and e(en 'ome 'ort of indeFing. There remain'+howe(er+ a fundamenta& mi'match #etween 51@5S and HD5S'.

The net re'u&t of the'e enhancement' wa' that the pure&y re&ationa& data#a'e' e(o&(edinto @#>ect-He&ationa& Data#a'e' ;@HD5S'ect mode& and are de'igned for &arge-grained o#>ect'.

ore recent&y+ another cha&&enge for the data#a'e (endor' wa' 'et #y the appearance ofthe etensible Mar#p %ang#age (M% N"!O. 1 i' a powerfu& communicationmechani'mP it contain' #oth the data and it' de'cription in a we&&-'tructured way. 6nfact+ it i' a teFt format with a particu&ar way of repre'enting information in ahierarchica& 'tructure ;ig. 2.9


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Infra!tructure_____________________________________________________________________________________________________

Fig. 2.8$M% as a hierarchical str#ct#re

We o#'er(e that:

The document 'tart' with the 1 dec&aration -m. /ersion=1%0P

%&& e&ement' ha(e 'tart and end tag': e.ement namee.ementname

%&& e&ement' are contained within one root e&ement: (oo3(oo3.

6n 1+ a c&ear di'tinction i' made #etween data and metadata+ 'yntaF and 'emantic'.uch &i*e in a re&ationa& data#a'e the 'ame 'tructure 'tore' different type' ofinformation #ut in 1 the 'tructure i' not fiFedP it can #e a&tered on-the-f&y+ a' &ong a'the 'yntaF i' re'pected. 1 i' the #a'i' for new architecture' in (ariou' domain' of6T: 'torage+ eFchange+ and repre'entation of information. The data#a'e (endor' cou&d ofcour'e not neg&ect the importance of 1+ 'o different way' to 'tore and retrie(e 1document' were de(e&oped. Traditiona& data#a'e (endor' ha(e a&& eFtended theirproduct' and propo'e two po''i#&e 'trategie':

6n the mapping approacha&& e&ement' of the 1 fi&e are 'tored a' 'eparate

row'. The ad(antage of thi' approach i' that+ once 'tored+ the data are acce''i#&e

with traditiona& too&' ;SI1


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Some @@D5S (endor' ha(e u'ed their *now-how and techno&ogy to #ui&d nativeM% databases. The idea i' to 'tore the e&ement' of the 1 document a' o#>ect'u'ing a 'pecia& ?uery &anguage data can then #e retrie(ed and updated.

Wor*ing with 1 document' in data#a'e' 'par*ed the need for a 'tandard ?uery

&anguage. Se(era& attempt' ha(e #een underta*en #y W!C+ one of them #eing -#ery.Iuery ha' an SI1-&i*e 'yntaF com#ined with path+ a ?uery &anguage de'igned toaddre'' part' of 1 document':

F! 5b &N (oo3

#$EE 5b6ut7orFirst Name = a.p7

6ND 5b6ut7orLast Name = 8imba..

ET9N 5btit.e

?uery 'tatement' are *nown a'%W1 e8pressions. 1WH ;pronouncedflower< i' anacronym that 'tand' for the four po''i#&e 'u# eFpre''ion'P thi' eFpre''ion type cancontain: @H+ 1,T+ WB,H,+ and H,TH). The @H 'tatement create' a co&&ectionof (aria#&e #inding'+ one for each node in the Qordered fore'tQ returned #y the patheFpre''ion. or each of the'e #inding'+ the 'u#'e?uent 'tatement' are eFecuted. Thenode' in the co&&ection are fi&tered #y the WB,H, c&au'e. H,TH) con'truct' there'u&t. The 1,T 'u#eFpre''ion ;not 'hown< #ind' a (aria#&e to a (a&ue.

$enchmaring of D$M*s

The performance of D5S' i' compared u'ing benchmars. The Transaction"rocessing "erformance Co#ncil or T"C i' a non-profit corporation founded #ydata#a'e manufacturer' to define tran'action proce''ing and data#a'e #enchmar*' andto di''eminate o#>ecti(e and (erifia#&e performance data. The term transactioni' oftenapp&ied to a wide (ariety of #u'ine'' and computer function'. 1oo*ed at a' a computerfunction+ a tran'action cou&d refer to a 'et of operation' inc&uding di'* read/write'+operating 'y'tem ca&&'+ or 'ome form of data tran'fer from one 'u#'y'tem to another.The T4C define' a tran'action+ a' it i' common&y under'tood in the #u'ine'' wor&d: acommercia& eFchange of good'+ 'er(ice'+ or money. % typica& tran'action wou&d inc&ude

the updating to a data#

mis thepowerofit

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