INFORMATICS PRACTICES
50 QUESTIONS
Q1.WhatisMACAddress?
Ans:Incomputernetworking,aMediaAccessControladdress(MAC)isauniqueidentifierassignedtomostnetworkadaptersornetworkinterfacecards(NICs)bythemanufacturerforidentification,andusedintheMediaAccessControlprotocolsub-layer.
Q2.Writetwoadvantagesofnetworks.
Ans: Advantages:i) Dataorinformationcanbesharedamongtheusers.
ii) Fastcommunicationcanbeachieved.
Q3.Writetwodisadvantagesofnetworks.
Ans:Disadvantagesofnetworks:
i.SophisticatedHardwareandsoftwaretechnologyisrequired.
ii.Expensivetoinstallnetwork.
Q4.Whatiscommunicationchannel?Namethebasictypesofcommunicationchannelsavailable.
Ans:Whatiscommunicationchannel?Namethebasictypesofcommunicationchannelsavailable.
Communication channelsmeantheconnectingcables thatlinkvarious workstations. There are3basictypesofcables:
Q5.Defineanetwork.
•TwistedPaircables
•Coaxialcables
•Fiber-opticcables
Ans:Acomputernetworkisasysteminwhichcomputersareconnectedtoshareinformationandresources.
Q6.WhatisIPaddress?
AnsAuniquenumberconsistingof4partsseparatedbydots,e.g.165.113.245.2EverymachinethatisontheInternethasauniqueIPnumber-ifamachinedoesnothavean IPnumber,itisnotreallyonthe Internet.
Q7.Whatisdomainname? Howisitalternativelyknown?
AnsTheuniquenamethatidentifiesanInternetsite.DomainNamesalwayshave2ormoreparts,separatedbydots.Thepartontheleftisthemostspecific,andtheparton therightisthemostgeneral.E.g.:matisse.net
Q1.WhatisOSS?
QuestionsandAnswer
AnsOpenSourceSoftwareisasoftwareavailablewithsourcecodeandfreetochange/edit/redistributeandimposednofurtherrestrictionsonproductoritsusage.
Q2.Expandtheterms:OSI,FLOSS,FSF,GNU,W3C,andPHP.
Ans:OSI: Opensource Initiative
FLOSS:FreeLibreandOpenSourceSoftware.
FSF:FreesoftwareFoundationcreatedforthepurposeofsupportingfreeMovement.
GNU:GNU’s Not Unix Project established with anobjective to create a systemCompatibletoUNIXbutnotidenticalwithit.
W3C:World Wide WEB consortium is responsible for producing the softwarestandardsforWorldWideWeb.
PHP:HypertextPre-processorisawidelyusedopensourceprogramminglanguageprimarilyforserversideapplicationsanddevelopingdynamicwebcontent.
Q3.Whatisfreesoftware?
Ans:FreeSoftwaremeansthesoftwareisfreelyaccessibleandcanbefreelyused,changed,improved,copiesanddistributedtoothers.
Q4.Definefreewareandshareware.
AnsThefreewareisthesoftwareavailablefreeofcostandallowscopyingandfurtherdistributionbutdoesnotallowsmodificationasitssourcecodeisnotavailable.
Sharewareisassoftwarewhichisavailableforredistributionforstipulatedtimebutaftersometimesomelicensefeeisrequiredtobepaid.
Q7.Whataredifferentfontcategories?
Ans:Therearetwocategoriesoffont:TrueTypeFontandOpenTypeFont.
TrueTypeFont:ItisdevelopedbyAppleandlicensedtoMicrosoft.Itis8bitfontwhichiscompatiblewithMicrosoftWindowsandMACOS.
OpenTypeFont:ItistheextensionoftheTrueTypeFontFormatwhichis16bitsfonandsupport65536characters(Unicodecharacters).
Q10.WhatisUnicode?
Ans10:Unicodeprovidesauniquenumberforeverycharacter,nomaterwhattheplatforms,nomatterwhattheprogram,nomatterwhatthelanguage.Unicodecanrepresent94140characters.
Q11.WhatisISCII?
Ans:IndianStandardCodeforInformationInterchange(ISCII)isacoding schemefor representingvariouswritingsystemsofIndia.ItencodesthemainIndicscriptsandaRomantransliteration.Whenwe typeIndianLanguage wordsphoneticallyinEnglishscriptandtoolwillautomaticallyconvertthemintocorrespondinglanguagewordscalledastransliteration.
Q20Findtheoutputofthefollowingcodesnippetwritteninjavapublicstaticvoidmain(String[
]args)
{
longa=78345,s1=0,s2=0,r;while(a>0)
{
r=a%10;
if(r%4==0)s1+=r;
elses2+=r;a/=10;
}
System.out.println("S1="+s1);System.out.println("S2="+s2);
}
Ans.Output:
s1=12
s2=15
Q21.CorrecttheerrorsinthefollowingprogramsegmentwritteninJAVA.Youarejustrequiredtowritethecorrectedcode,underlyingthecorrectionsmade.
publicStaticVoidMain(String[]args)
{
IntegerNos=100;while(Nos=45)
{
If(Nos%5=0);Nos+=10;
otherwiseNos+=20;
}
}
Ans:CorrectedCode
publicstaticvoidmain(String[]args)
{
intNos=100;while(Nos=45)
Chapter-4
1.WhatwouldbethenameoftheeventhandlermethodintheListSelectionlistenerinterfaceforalistnamelyCheckListtohandleitsitemselections?
a.CheckListValueChanged()b.getSelectedValue()c.clearSelection()Ans:a.CheckListValueChanged()
2.Whichcontroldisplaystextthattheusercannotdirectlychangeoredit?a.TextFieldb.Checkboxc.Comboboxd.Label
Ans:d.Label
3.Whichcontrolprovidesbasictexteditingfacility?a.TextFieldb.Checkboxc.Comboboxd.Label
Ans:a.TexfField
4.Occurrenceofanactivityiscalled:
a.Functionb.Classc. Objectd.EventAns:d.Event.
5.WhichpropertyisusedtosetthetextoftheLabel?
a.fontb.textc.named.iconAns:b.text
6.Theobjectcontainingthedatatobeexhibitedbythecomboboxbywhichproperty.
a.editableb.modelc.selectedIndexd.selectedItemAns:b.model
7.WhatisGUIprogramming?
Ans:AGUI(GraphicalUser Interface)isaninterfacethatusespicturesandothergraphicentitiesalongwithtext,tointeractwithuser.
8.HowisswingrelatedtoGUIprogramming?
Ans:WecancreateaGUIapplicationonJavaplatformusingSwingAPI(ApplicationProgrammingInterface),whichispartofJavaFoundationClasses(JFC).
9.Whatisanevent?Whatiseventhandler?
Ans:Aneventisoccurrenceofsomeactivitieseitherinitiatedbyuserorbythesystem.Inordertoreact,youneedtoimplementsomeEventhandlingsysteminyourApplication.ThreethingsareimportantinEvenHandling-
EventSource:ItistheGUIcomponentthatgeneratestheevent,e.g.Button.
EventHandlerorEventListener:Itisimplementedasintheformofcode.ItreceivesandhandleseventsthroughListenerInterface.
EventObjectorMessage:Itiscreatedwheneventoccurs.ItcontainsalltheinformationabouttheeventwhichincludesSourceofeventandtypeof
eventetc.
10.WhatisthedefaultnameofactioneventhandlerofabuttonnamelyTestBtn?Ans:privatevoidTestBtnActionPerfomed(java.awt.action.ActionEventevt){}.
11.Whatpropertywouldyousettoassignaccesskeytoabutton?
Ans:mnemonicpropertyisusedtoassignaccesskeyorshortcut(Alt+Key).
12.Whichmethodcanprogrammaticallyperformstheclickactionofapushbutton?Ans:privatevoidTestBtnActionPerfomed(java.awt.action.ActionEventevt){}.
13.Whichpropertywouldyousetthesettingthepasswordcharacteras‘$’?Ans:echoChar
14.Whichmethodreturnsthepasswordenteredinapasswordfield?Ans:char[]getPassword().
15.Whichlistpropertydoyousetforspecifyingtheitemsforthelist.Ans:model
16.Whichmethodwouldyouusetodeterminetheindexofselectediteminalist?Ans:intgetSelectedIndex().
17.Whichmethodwouldyouusetoinsertanitematspecifiedindex,inthelist?Ans:voidsetSelectedIndex(intindex).
18.Howyoucandeterminewhether5thiteminalistisselectedornot?Ans:isSelectedIndex(4).
19.Whichmethodyouwouldusetoinsert‘Hello’at10thpositionintheTextAreacontrol.Ans:voidinsert(“Hello”,9).
20.WhichmethodyouwouldliketousetoinsertanIcon(picture)onaPushButton.Ans:voidsetIcon(Icon).
21.WhichpropertywouldyouliketosettomakeaComboboxeditable?Ans:editable.
22.WhatisLayoutManager?NamethelayoutmanagersofferedbyNetBeans?
Ans:LayoutmanagersenableyoutocontrolthewayinwhichvisualcomponentsarearrangedinGUIformsbydeterminingthesizeandpositionofcomponentswithincontainers.
Thereareseventypesoflayoutareavailable–
•FlowLayout
•GridLayout
•CardLayout
•SpringLayout
•BorderLayout
•GridBagLayout
•BoxLayout
23.Namethreecommonlyusedpropertiesandmethodsofthefollowingcontrols.
(a)textfield(b)textarea(c)CheckBox
Ans:(a)Properties:text,font,editable.Methods:voidsetText(),StringgetText(),voidsetEditable(boolean).
(b)Properties:enabled,editable,wrapStyleWordMethods:setText(),getText(),isEditable()
(c)Properties:font,text,selected.Methods:getText(),isEnabled(),isSelected().
24.Whatisdispose()usedfor?
Ans:dispose()isusedforhideanddisposeoftheframewhentheuserclosesit.Thisremovestheframefromthescreenandfreesupanyresourcesusedbyit.
25.Whatisthedifferencebetween-
(a)TextfieldTextarea
(b)Textfieldpasswordfield
(c)RadioButtonCheckBox
Ans:(a)Atextfield’stextpropertycanholdsinglelineoftextunlessitisanHTMLtext.Whileatextarea’stextcanholdanynumberoflinesoftextdependinguponitsrowsproperty.
(b)Thoughatextfieldandapasswordfieldcanobtainasinglelineoftextfromtheuser,yetthesearedifferent.
Apasswordfielddisplaystheobtainedtextinencryptedformonscreenwhiletextfielddisplaystheobtainedtextinunencryptedform.
(c)RadioButton:AjRadioButtoncontrolbelongstoJRadioButtonclassofSwingcontrols. Itisusedtogetchoicesfromtheuser.Itisgroupedcontrol,sothatonlyonecanbeselectedatatimeamongthem.RadioButtonworksingroup,sothattheymustbekeptinaButtonGroupcontainercontrollikesothatonlyonecanbeselectedatthesametime.
SomefeaturesofjRadioButtoncontrolare-
YItcan beused toinput choicestypedinput totheapplication.
YOnlyoneRadiobuttoncanbeselectedatatime.
YTheymustbekeptinaButton Groupcontainer controlto formagroup.
Checkbox:AjCheckBoxcontrolbelongstoJCheckBoxclassofSwingcontrols.Itindicateswhether
aparticularconditionisonoroff.YoucanuseCheckboxestogiveuserstrue/falseoryes/nooptions.CheckBoxesmayworksindependentlytoeachother,sothatanynumberofcheckboxescanbeselectedatthesametime.
SomefeaturesofjCheckBoxcontrolare-
YItcanbeusedtoinputTrue/FalseorYes/Notypedinputtotheapplication.
YMultiplecheckboxescanbeselectedatthesametime.
26.Whatisthesignificanceoffollowingpropertiesofatextarea?
(a)lineWrap(b)wrapStyleword
Ans:(a)DefinesWrappingfeatureenable/disable(b)Determineswherelinewrappingoccurs. Iftrue,thecomponentattemptstowraponlyatwordboundaries.Thispropertyisignoredunlesslinewrapissettotrue.
27.Whatisthesignificanceofabuttongroup? Howdoyoucreateabutton group?
Ans:WemustaddaButtonGroupcontroltotheframeto groupthecheckboxesbyusingButtonGrouppropertyofthecheckbox.Bydraggingbuttongroupcontrolfrompalettewindow.
28.CreateaJavaDesktopApplicationtofindtheincentive(%)ofSalesforaSalesPersononthebasisoffollowingfeedbacks:
Feedback / Incentive(%)MaximumSales
ExcellentCustomerFeedbackMaximumCountCustomer / 10
8
5
Note:thatthesalesentryshouldnotbespace.Calculatethetotalincentiveas:Salesamount*Incentive.ThefeedbackwillbeimplementedinJCheckBoxcontrols.UsingaJButton’s(ComputeIncentive) clickeventhandler,displaythetotalincentivesinaJTextFieldcontrol.Assumethenomenclatureof theswingcomponentsofyourown.
NotethattheJFramefromIDEwindowwillbeshownas given:
Ans:-privatevoidbtnIncActionPerformed(java.awt.ActionEventevt){intsales=0;
if(!txtSales.getText().trim().equals(“”)){
sales-Integer.parseInt(txtSales.getText().trim());
}
doubleincentive=0.0;
if(jCheckBox1.isSelected()){incentive=incentive+0.1;
}
if(jCheckBox2.isSelected()){incentive=incentive+0.8;
}
if(jCheckBox3.isSelected()){incentive=incentive+0.05;
}
txtInc.setText(““+Math.round(sales*incentive));
}
29.AssumethefollowinginterfacebuiltusingNetbeansusedforbillcalculationofaice-creamparlor.Theparloroffersthreeveritiesofice-cream–vanilla,strawberry,chocolate.VanillaicecreamcostsRs.30,StrawberryRs.35andChocolateRs.50.Acustomercanchoseoneor
moreice-creams,withquantitiesmorethanoneforeachofthevarietychosen.Tocalculatethebillparlormanagerselectstheappropriatecheckboxesaccordingtotheveritiesofice-creamchosenbythecustomerandentertheirrespectivequantities.
WriteJavacodeforthefollowing:
a.Ontheclickeventofthebutton‘Calculate’,theapplicationfindsanddisplaysthetotalbillofthecustomer.Itfirstdisplaystherateofvariousice-creamsintherespectivetextfields. Ifauserdoesn’tselectacheckbox,therespectiveice-creamratemustbecomezero.Thebilliscalculatedbymultiplyingthevariousquantitieswiththeirrespectiverateandlateraddingthemall.
b.OntheClickeventoftheclearbuttonallthetextfieldsandthecheckboxesgetcleared.
c.Ontheclickeventoftheclosebuttontheapplicationgetsclosed.
Ans:(a)
privatevoidjBtncalculateActionPerformed(java.awt.event.ActionEventevt)
{
if(jchkStrawberry.isSelected()==true)jTxtPriceStrawberry.setText("35");else
{
jTxtPriceStrawberry.setText("0");jTxtQtyStrawberry.setText("0");
}
if(jChkChocolate.isSelected()==true)jTxtPriceChocolate.setText("50");else
{
jTxtPriceChocolate.setText("0");jTxtQtyChocolate.setText("0");
}
if(jChkVinella.isSelected()==true)jtxtPriceVinella.setText("30");else
{
jtxtPriceVinella.setText("0");jTxtQtyVinella.setText("0");
}
intr1,r2,r3,q1,q2,q3,a1,a2,a3,gt;r1=Integer.parseInt(jTxtPriceStrawberry.getText());r2=Integer.parseInt(jTxtPriceChocolate.getText());r3=Integer.parseInt(jtxtPriceVinella.getText());q1=Integer.parseInt(jTxtQtyStrawberry.getText());q2=Integer.parseInt(jTxtQtyChocolate.getText());q3=Integer.parseInt(jTxtQtyVinella.getText());a1=r1*q1;
jTxtAmtStrawberry.setText(""+a1);a2=r2*q2;jTxtAmtChocolate.setText(""+a2);a3=r3*q3;jTxtAmtVinella.setText(""+a3);gt=a1+a2+a3;jTxtTotalAmt.setText(""+gt);
}
Ans.(b)
privatevoidjBtnClearActionPerformed(java.awt.event.ActionEventevt)
{
jTxtPriceStrawberry.setText("");jTxtPriceChocolate.setText("");jtxtPriceVinella.setText("");jTxtQtyStrawberry.setText("");jTxtQtyChocolate.setText("");jTxtQtyVinella.setText("");jTxtAmtStrawberry.setText("");jTxtAmtChocolate.setText("");jTxtAmtVinella.setText("");jchkStrawberry.setSelected(false);jChkChocolate.setSelected(false);jChkVinella.setSelected(false);
}
Ans:(c)
privatevoidjBtncloseActionPerformed(java.awt.event.ActionEventevt)
{
System.exit(0);
}
{
if(Nos%5==0)_Nos+=10;
else
Nos+=20;
}
}
HTML AND XML
SolvedQuestions:
1.Identifythewebbrowsersoftwarefromthefollowingoptions:
(a)ApacheWebServer(b)MSWord(c)HTML(d)MozillaFirefox
Ans.(d)MozillaFirefox
2.Adocumentiscreatedbywebserverwheneverabrowserrequeststhedocuments.
(a)active(b)static(c)dynamic(d)noneoftheabove
Ans.(c)Dynamic
3.Adocumentisafixedcontentdocumentthatiscreatedbywebserverwheneverabrowserrequeststhedocuments.
(a)active(b)static(c)dynamic(d)noneoftheabove
Ans.(b)Static
4.Identifythewebserversoftwarefromthefollowingoptions:
(a)Apache(b)MSWord(c)HTML(d)MozillaFirefox
Ans.(a)Apache
5.Theaddressofaresourceonthenetisknownas:
(a)ISP(b)HTTP(c)URL(d)WWW
Ans.(c)URL
6.AprogramthatservesrequestedHTMLfilesandpages.
(a)WebAddress(b)WebPage(c)WebServer(d)Noneofthese
Ans.(c)WebServer
7.WhatisUniformResourceLocator?
Ans:Theuniformresourcelocator(URL)istheuniqueidentifierofawebpage.Theaddress orURLofthecurrentpageyouareonappearsinthe"AddressBar"ofthewebbrowser.Youcan godirectlytoawebpageifyouknowitsURLbysimplytypingtheURLintheaddress bar.YoucanclickintheaddressbaratanytimeandoverwritethecurrentaddresswithanotherURLtojumptoadifferentwebpage.ThemostgeneralformofaURLsyntaxisasfollows:
Protocol://domainname/directorypath/objectname Forexample:
8.WhatisWebServer?
Ans:Webserverdelivers(serves)content,suchaswebpages,usingtheHypertextTransferProtocol(HTTP),overtheWorldWideWeb.
9.WhatisWebBrowser?
Ans:Awebbrowserisaclientthatinitiatescommunicationbymakingarequestforaspecificresource.Theserverthenrespondswiththecontentofthatresource,oranerrormessageifunabletodoprovidethecontentsduetoanyreason.
1.HTMLtagsmustbewrittenwithin:
(a)(b){} (c)[ ] (d)()
Ans:(a)
2.WhichofthefollowingisthecorrectstructureofHTMLtags?
(a)HTML/HTML<HEAD/HEADBODY/BODY
(b)<HTML<HEAD/HEAD/HTMLBODY/BODY
(c)HTML<HEADBODY/BODY/HEAD/HTML
(d)<HTML<HEAD/HEADBODY/BODY/HTML
Ans:(d)<HTMLHEAD/HEADBODY/BODY/HTML
3.WhatisHTML?
Ans:HTMLstandsforHyperTextMarkup Language.ItisamarkuplanguageusedtocreateHTMLdocuments.AnHTMLdocumentdefinesawebpage.
4.Definehtml>tag
Ans:Thehtml>tagidentifiesthedocument.AnHTMLdocumentbeginwithhtml>endswith
/html.
5.GivetwodifferencesbetweenHTMLandXML.
Ans:ThethreedifferencesbetweenHTMLandXMLare:
1.HTMLisdesignedtodisplaydataandhence,focussedonthe‘look’ofthedata,whereasXMLisdesignedtodescribeandcarrydataandhence,focuseson‘whatdatais’.
2.InHTMLtagsarepredefined,whileinXML,tagscanbecreatedasperneeds.
3.HTMLtagsarenotcasesensitive,whereasXMLtagsarecasesensitive
1.CompareHTMLandXMLbrieflyAns.- HTMLversu XML
CHAPTER14
MYSQLREVISIONTOUR
1.Whatisdifferencebetweencharandvarchar?
Ans-Thedifferencebetweencharandvarcharisthatoffixedlength and variable length.TheCHARdatatypesspecifiesafixedlengthcharacterstring.WhenacolumnisgivendatatypeasCHAR(n)thenMySQLensuresthatallvaluesstoredinthatcolumnhavethislength.ButonotherhandwhenacolumnisgivendatatypeasVARCHAR(n),thenthemaximumsizeofavalueinthiscolumnstoresexactlywhatwespecify.
2.Whatdoyouunderstandbythetermsprimarykeyanddegreeofarelationinrelationaldatabase?
Ans:PrimaryKey:Aprimarykeyisasetofoneormoreattributesthatcan uniquelyidentifytupleswithintherelations.ThenumberofattributesinarelationiscalledDegreeofarelationinrelationaldatabase.
3.Whatdoyouunderstandbythecandidatekeyandcardinalityofarelationinrelationaldatabase?
CandidateKey:Allattributecombinationsinsidearelationthatcanserveasprimarykey(uniquelyidentifiesarowinarelation)areCandidateKeysastheyarecandidatesfortheprimarykeyposition.Thenumberofrowsinarelationisknownascardinalityofarelation.
4.ConsiderthefollowingtablesItemandCustomer.WriteSQLcommandsforthestatement
(i)to(iv)andgiveoutputsforSQLqueries(v)to(viii)Table:ITEM
Table:CUSTOMERC_IDCustomerNameCityI_ID
S.no / CUSTOMERC_ID / CustomerName / City / I_ID
01 / 01 / N.Roy / Delhi / LC03
02 / 06 / H.Singh / Mumbai / PC03
03 / 12 / R.Pandey / Delhi / PC06
04 / 15 / C.Sharma / Delhi / LC03
05 / 16 / K.Agrawal / Bangalore / PC01
(i)TodisplaythedetailsofthoseCustomerswhosecityisDelhi
.Ans:SelectallfromCustomerWhereCity=”Delhi”
(ii)TodisplaythedetailsofItemwhosePriceisintherangeof35000to55000(Bothvaluesincluded).
Ans:SelectallfromItemWherePrice=35000andPrice<=55000
(iii)TodisplaytheCustomerName,CityfromtableCustomer,andItemNameandPricefromtableItem,withtheircorrespondingmatchingI_ID.
Ans:SelectCustomerName,City,ItemName,PricefromItem,Customerwhere
Item.I_ID=Customer.I_ID.
(iv)ToincreasethePriceofallItemsby1000inthetableItem.
Ans:UpdateItemsetPrice=Price+1000
(v)SELECTDISTINCTCityFROMCustomer.
Ans:CityDelhi,Mumbai,Bangalore
(vi)SELECTItemName,MAX(Price),Count(*)FROMItemGROUPBYItemName;
Ans:ItemNameMax(Price)Count(*)PersonalComputer370003Laptop570002
(vii)SELECTCustomerName,ManufacturerFROMItem,CustomerWHEREItem.Item_Id=Customer.Item_Id;
Ans:CustomerNameManufacturerName
N.RoyPQR
H.SinghXYZR.Pandey COMPC.Sharma PQRK.AgarwalABC
(viii)SELECTItemName,Price*100FROMItemWHEREManufacturer=‘ABC’;
Ans:ItemNamePrice*100PersonalComputer3500000Laptop5500000
CHAPTER-15
DATABASETRANSACTIONS
SOLVEDQUESTIONS
1.Defineatransaction.
Ans.-Atransactionisalogicalunitofaworkthatmustsucceedorfailinitsentirely.Itisanatomicoperationwhichcanbedivideduntosmalleroperations.
2.Whatarethetwowaysinwhichmultipletransactionscanbeexecuted?
Ans.-Multipletransactionscanbeexecutedinoneofthefollowingtwoways:
(i)Serially(ii)Concurrently
3.What is asavepoint?
Ans.-Savepointsarespecialoperationsthatallowyoutodividetheworkofatransactionintodifferentsegments.Incaseofafailure,youcanexecuterollbackstothesavepointonly,leavingpriorchangesintact.
4.Whattoyouunderstandbyadatabasetransaction?
Ans.-Adatabasetransactionisalogicalunitofworkthatmustsucceedorfailinitsentirely.
5.WhydounderstandbytransactionCOMMITandROLLBACK?
Ans-COMMITingatransactionmeans all thesteps ofatransactionarecarriedoutsuccessfullyandalldatachangesaremadepermanentinthedatabase.TransactionROLLBACKmeanstransactionhasnotbeenfinishedcompletelyandhencealldatachangesmadebythetransactioninthedatabaseifany,areundoneandthedatabasereturnstothestateasitwasbeforethistransactionexecutionstarted.
6.WhatdoyouunderstandbyACIDpropertiesofdatabasetransaction?
Ans.-Toensurethedata-integrity,thedatabasesystemmaintainsthefollowingpropertiesoftransaction.ThepropertiesgivenbelowaretermedasACIDproperties-anacronymderivedfromthefirstletterofeachoftheproperties.
(i)Atomicity-This property ensures that either all operations of the transactions arereflectedproperlyinthe database, none are. Atomicity ensures either al-or-noneoperationsofatransactionarecarriedout.
(ii)Consistency-Thispropertyensuresthatdatabaseremainsinaconsistentstatebeforethestartoftransactionandafterthetransactionisover.
(iii)Isolation-Isolation ensures that executing transaction execution in isolation i.e. isunawareofothertransactionsexecutingconcurrentlyinthesystem.
(iv)Durability-Thisproperty ensuresthatafterthesuccessfulcompletionofatransactioni.
ewhenatransactionCOMMITs,thechangesmadebyittothedatabasepersisti.eremaininthedatabaseirrespectiveofotherfailures.
7.Whatthefunctionisofredoandundologs?
Ans.-Everydatabasehasasetofredologfiles.Itrecordsallchangeindataincludingbothcommittedanduncommittedchanges.Undologsstoredrollbackeddata.
8.WhatTCLcommandsaresupportedbySQL?
Ans.-SQLsupportsfollowingTCLcommands
•BEGIN|STARTTRANSACTION-Marksthebeginningofatransaction
•COMMIT-Endsthecurrenttransactionbysavingdatabasechangesandstartsanew
transaction.
•ROLLBACK-Endsthecurrenttransactionbydiscardingchangesandstartsanew
transaction.
•SAVEPOINT-Definesbreakpointsforthetransactionstoallowpartialrollbacks.
•SETAUTOCOMMIT-Enablesordisablethedefaultautocommitmode.
Q.WriteShortNoteson:e-Governance,e-Business,e-Learning.
Answer: e-Governanceinvolvesapplicationswhichareusedbygovernmentagencies/organizationstoprovidebettergovernance.
e-Businessapplicationsusetechnologytoeffectivelyaccessanddeliverbusinessrelatedservicesandperformvariouskindsofbusinesstransactions.
e-Learningapplicationsusetechnologytoeffectivelydeliverandmonitorlearningandteachingprocesses.Theyhelpthetrainertoorganizeandmanagehis/herlessonplans,presentthemtostudents/learners,evaluateandtakethefeedbacktoenhancefine-tunethisprocessinfuture.
Q.WhatareFront-end(Theuserinterface)andback-end(Thedatabase)?
Answer:AnITapplicationhastwomajorparts:Front-end(Theuserinterface)andback-end(Thedatabase).Thefront-endof anITapplicationis usuallyagroupofoneormoreformsthroughwhichtheuserenterstheinputvaluesandisshownthecorrespondingoutput.Agoodfront-endensurestheacceptanceoftheapplicationinthefirstgo.Theback-endofanITapplicationis thedatabaseinwhich all thedataisstored.Thisdatabaseresidesintheserver.Allthedatawhichisrequestedbythefront-endissuppliedbyback-end.Agoodback-endensuressustainability,efficiencyandeasymodificationoftheapplication.
Q.WhatarethetermsinvolvedinDevelopmentofanITapplication?
DevelopmentofanITapplicationinvolvescreationoffront-end,back-end,andconnectingthesetwo.Italsoinvolvestestingtheapplicationandthenimplementingit.
Q.WhatsocialandeconomicimpactsarefoundofICT.?
Answer:SocietyisimpactedasduetoICTpeoplechangetheirwayofconductingthetransactionsandthussavetheirtime,money,andenergy.Economyisimpactedas ICTleadstofastcompletionofdatatransferanddataprocessingjobs.ICTalsobringstransparencyintheadministration.
Q.WhatdoyoumeanbyInfomania?
Answer:Infomaniaistheconditionofreducedconcentrationcausedbycontinuallyresponding
toelectroniccommunicationssuchase-mail,SMSs,MMSsetc.ICTismakingmoreandmorepeopleinfomaniac.Thisismakingsomepeoplewastetheirproductivetimeintheoffice,neglecttheirfamiliesandduties.Somepeoplearealsoinahabitoffrequently checkingtheire-mailsevenwhentheyareonvacationwiththeirfamilies.WehavetobecarefulintheuseofICTsothatweuseitconstructivelyandnotgetobsessedwithitandbecomeinfomaniacs.
Q.WhatOSandfontsareusedforIndicLanguageSupport?
Answer:MacOS10.5supportsDevanagari,Gujarati,GurmukhiandTamil.Linuxbased
desktopssupportBengali,Devnagari,Gujarati,Kannada,Malayalam,Oriya,Tamil,TeluguandGurmukhi,
Q.WritethestepsforenablingIndicLanguageSupportinWindows.
Answer:Windows7andWindowsVistaincludeallthenecessaryfilestosupportIndic
languagesComplex(Indic)textsupportisautomaticallyenabled.ThereforeyoujustneedtoenablethekeyboardforthelanguagethatyouwanttousebyfollowingthestepsintheEnableakeyboardlayoutsection.ForWindowsXP,someadditionalsetupmayberequiredtosupportIndiclanguages.ThereforeyoufirstfollowthestepsgivenunderEnablingInternationalLanguageSupportinWindowsandthenproceedwiththestepsgivenundertheEnableakeyboardlayoutsection.
Q.Writethestepsforturningonthelanguagebar.
Ifyoudonotseethelanguagebarinthetaskbar(atthebottomofthedesktop)orfloatingonthedesktop
pleasedothefollowing:
Step1:ClickStart,clickControlPanel,andthendouble-click RegionalandLanguageOptions.Step2: OntheLanguagestab,underTextservices andinputlanguages, clickDetails asshownin
Figure8.
Step3: UnderPreferences,clickLanguageBar.
Step4: SelecttheShowtheLanguagebaronthedesktopcheckbox.
Figure3LanguageBarSettingsinWindowsXP
Note:YoucanswitchbetweendifferentlanguagesbyclickingonthelanguagebarandchangingthelanguageorbypressingtheleftALT+SHIFTkeys.
Q.HowFontsinWindowsareInstalled?
Step1: GotoWindowsFontsfoldere.g.C:\Windows\Fonts.(Thepathmay differonsome
computers.)
Step2:Copy-pastethefontfileintothisfolder.Windowswillnowinstallthefontfile.Step3: Onceinstalledthefontwillbeavailableinyourtext-basedapplications.
Q.HowcanbeestablishedFront-EndandDatabaseConnectivity?
AdatabaseapplicationconsistsofFront-EndandDatabase(Back-end).Thesetwoentitiescannotworkinisolation.Whateverdataisenteredbytheuserhastogotothedatabaseand whateverrelevantdataisextractedfromthedatabaseistobeshowntotheuserthroughtheFront-End.Therefore,theFront-EndandtheDatabaseofanIT applicationmustbeconnected.ThisconnectivityisachievedaslearntinChapter 6(DatabaseConnectivity).Iftheapplicationiswebbasedthentheconnectivityisachievedusingsomescriptinglanguage(likevbScriptorJavaScript).
Q.ArethereWebsitesinIndianlanguages?Writeaboutthem?
Answer:Yes,thesedaysmultipleGovernmentandprivateorganizationsareprovidingtheirwebsitesinHindiandotherregionallanguagesalso.Theaimistoprovidetheirserviceseventothecommon
peopleinremoteareas.Smalltownswherecomputersandinternethavereached,informationonthenetshouldalsobeavailableinregionallanguagessothatpeoplenotknowingEnglishcanalsohaveaccess totheinformation.Languageshouldnotbeahinderancebutasupporttolearning.Understaningtheimportanceofregionallanguages,manywebsiteshavealsoprovidedtranslationservicessothatthesamepagecanbeviewedinanylanguageofuser'schoice.