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ProsandConsofNoSQLDatabasesBasedonpapersbyChristofStrauchandbyErik
Meijer,GavinBierman
PresentaBonbyKristjanKoolSoEwareEngineeringSeminar,11.11.2011
Outline
Ipart„NoSQLdatabase“byChristofStrauch
• Mo#vesandMainDrivers• Cri#cism
IIpartAco‐RelaBonalModelofDataforLargeSharedDataBanksbyErikMeijerandGavinBierman
• Abouteconomicalbarriersandpossibilites
IntroducBon:NoSQL
“thewholepointofseekingalternaBvesisthatyouneedtosolveaproblemthatrelaBonaldatabasesareabadfitfor”
EricEvans,reintroducerofthetermNoSQLinearly2009
IntroducBon:NoSQL
„NextGeneraBonDatabasesmostlyaddressingsomeofthepoints:beingnon‐relaBonal,distributed,open‐sourceand
horizontallyscalable“
NoSQLdefiniBon@hZp://nosql‐database.org/
IntroducBon:NoSQL
ClassificaBonofNoSQL(accordingtopaper)
• key/valuestores,• documentdatabases,
• andcolumn‐orienteddatabases.
IntroducBon:NoSQL
Source:NathanHurst’sblogpost
MoBvesandMainDrivers
• AvoidanceofUnneededComplexity– SomeBmesBASE(BasicallyAvailable,SoEstate,Eventualconsistency)isgoodenough
• AvoidanceofExpensiveObject‐RelaBonalMapping– MostoftheNoSQLdatabasesaredesignedtostoredatastructuresthatareeithersimpleormoresimilartotheonesofobject‐orientedprogramminglanguagescomparedtorelaBonaldatastructures.
MoBvesandMainDrivers
• HorizontalScalabilityandRunningonCommodityHardware
• DecreasedComplexityandCostofSebngupDatabaseClusters– PCclusterscanbeeasilyandcheaplyexpandedwithoutthecomplexityandcostof’sharding,’whichinvolvescubngupdatabasesintomulBpletablestorunonlargeclustersorgrids.
MoBvesandMainDrivers
• CompromisingReliabilityforBeZerPerformance
• TheCurrent“Onesizefit’sitall”DatabasesThinkingWasandIsWrong– TheconBnuousgrowthofdatavolumes(tobestored)
– ThegrowingneedtoprocesslargeramountsofdatainshorterBme
• TheMythofEffortlessDistribuBonandParBBoningofCentralizedDataModels
MoBvesandMainDrivers
• MovementsinProgrammingLanguagesandDevelopmentFrameworks– TheNoSQLdatabasesreactonthistrendandtrytoprovidedatastructuresintheirAPIsthatareclosertotheonesofprogramminglanguages(e.g.key/value‐structures,documents,graphs).
• RequirementsofCloudCompuBng• TheRDBMSplusCaching‐LayerPaZern/Workaroundvs.SystemsBuiltfromScratchwithScalabilityinMind
MoBvesandMainDrivers
• Yesterday’svs.Today’sNeeds– PolyglotPersistence– we’removingtowardsapluralisBcapproachtostoringourdata• Scalability• Highavailability• Faulttolerance• Distributability• Flexibility(i.e."schemaless"databases)• NewtypesofapplicaBonslikesocialnetworkingwebsites
MainDrivers
Source:The451GroupblogarBcle
Amazone
exisBngdatabaseproductsand
vendorswerenotsuitabletomeetrequirementsof
Web2.0companies
CriBcism
• ScepBcismontheBusinessSide– Support(SLA,quaranBes)– nobodytoblameforFailures
• NoSQLasaHype– movementseemslackingthefulfillmentofitspromises
CriBcism
• NoSQLasBeingNothingNew– Similardatabaseshavebeenaroundfordecades(LotusNotes,Object‐orientedDB‐s,Berkleyetc)
• NoSQLMeantasaTotal“NotoSQL”– irritaBonaboutthetermanditsfirstnoBonasatotalneglectofrelaBonaldatabaseshasleadtomanyprovokingstatements
CriBcism
• RequirementsofAdministratorsandOperators– hugedifferencesamongtheNoSQLdatabases
• Performancevs.Scalability– YoushouldusefornewapplicaBonsthetoolfibngthejobbest
– ACIDversBASE– non‐relaBonaldatabases—justlikerelaBonalones—areno“onesizefitsall”soluBonseither.
CriBcism
• „NoSQLisjustaboutscalabilityand/orperformance.”
• “NoSQLisjustdocumentdatabases,orkey‐valuestores,or...”
• “IcandoNoSQLjustaswellinarelaBonaldatabase.”
• “NoSQLisawholesalerejecBonofrelaBonaldatabases.”
IIpart‐economicsituaBon
ThecurrentNoSQLmarketsaBsfiesthethreecharacterisBcsofamonopolisBcallycompeBBvemarket:
• thebarrierstoentryandexitarelow;• therearemanysmallsuppliers;
• andthesesuppliersproducetechnicallyheterogeneous,highlydifferenBatedproducts.
economicsituaBon
• MonopolisBcallycompeBBvemarketsareinconsistentwiththecondiBonsforperfectcompeBBon.
• HenceinthelongrunmonopolisBcallycompeBBvefirmswillmakezeroeconomicprofit.
economicsituaBon
• Today,therelaBonaldatabasemarketisaclassicexampleofanoligopoly.
• Themarkethasafewlargeplayers(Oracle,IBM,MicrosoE,MySQL)
• thebarrierstoentryarehigh,andallexisBngSQL‐basedrelaBonaldatabaseproductsarelargelyindisBnguishable.
• Oligopoliescanretainhighprofitsinthelongrun;todaythedatabaseindustryisworthanesBmated$32billionandsBllgrowinginthedoubledigits.
Howtoovercomethebarriers?
• JustasCodd’sdiscoveryofrelaBonalalgebraasaformalbasisforSQLshiEedthedatabaseindustryfromamonopolisBcallycompeBBvemarkettoanoligopoly
SoluBon?
• commonabstractmathemaBcaldatamodelandanassociatedquerylanguageforNoSQLthatremovesproductdifferenBaBonatthelogicallevel.
• Theavailabilityofsuchbasiscanprovideenoughcri#calmasstoconvincebusinesses,developers,educa#onalins#tu#ons,etc.toinvestinNoSQL.
Dowebeliveit?
Fact:(some)vendorsneedtomakeprofit!?
• opensourcevers.closedsource?• consolidaBonofthevendors(ongoing)?• Intra‐corporateneedsversuspublicneeds?• AdapBon(withDBMS)?• Standards?• etc
HowtoreallyovercomeOligopoly?
Perhapsit’sjustanormalprocess:
Source:HypecyclefromWikipedia
FurtherRecommendedReadings
• MichaelStonebrakerarBcles:– “OneSizeFitsAll”:AnIdeaWhoseTimeHasComeandGone“
– TheEndofanArchitecturalEra(It’sTimeforaCompleteRewrite)
– SQLDatabasesv.NoSQLDatabases– NoSQLandEnterprises
• StefanEdlich(authoroftheworldfirstNoSQLbook)– hZp://nosql‐database.org/
• MyNoSQLbyAlexPopescu
• NoSQLtapesprojectbyTimAnglade
• NoSQLintheEnterprisebySouravMazumder
ThankYouPs!It’sgoingtobeavictoriousevening
Post‐presentaBonQuataBons
“Thosewhodonotunderstandthelessonsfrompreviousgenera=onsystemsaredoomedtorepeattheirmistakes.”Inotherwords,“Standontheshouldersofthosewhocamebeforeyou,notontheirtoes.”
M.Stonebraker,„NoSQLandenterprises“
Post‐presentaBonQuataBons„Considerahouseholdanalogy:if,asyoubuildahouse,yourunwiringinconduit,externaltoyourwalls,andsurface‐mountyourfixtures,you’llalwaysbeabletoupgradeyourwiring,orrepairawiring
segmentgonebad.Butifyouknowthattheelectrical,andmaybecableTVandcomputernetworkwiringtobeinstalledwillsuityourpurposesforthelongterm,thenitmakesperfectsensetorunyourwiringin‐wall.Youcanalwaysopenthewallsagainifneedbe,andifyou’rereasonablycertainthatyouwon’tneedto,thenrunningthe
wiringinternallyistherightdecision.ItwilllookbeMertomostpeople,makeiteasiertopushfurnitureagainstthewallandwill,arguably,besomewhatsafer.Ingeneral,yourhomewillhaveamorefinishedlooktoit.Ifonedayyourneedschangeandyouneedtoopenthewallsagain,thatwillnotnecessarilymeanyoumadeabaddecision.„
AndrewJ.Brust,„NoSQLandtheWindowsAzureplarorm“
Post‐presentaBonQuataBons
„NoSQLIsfortheBirds„
BenjaminBlack
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