MYSQL网页设计Oracle 和 MIcrosoft SQL 的分歧

客户还是可以使用DBaaS系统所能提供的所有能力。数据库云服务消除了组织对专职人员、本地数据库存储设备的需要。他们不必安装、配置和维护任何软硬件。oracle
仍是有良多的分歧,转贴以下:http://www.bristle.com/Tips/SQL.htm#Oracle%20Tips


TableofContents:OracleTipsSQLTipsSELECT*andmoreMaterializedViewPL/SQLTipsSQLNavigatorTipsSeeAlsoMSSQLServerTipsSQLTipsDynamicSQLinaStoredProcedureSQLEnterpriseManagerTipsKeyboardShortcutsSQLGeneratingSQLSeeAlsoDifferencesBetweenOracleandMSSQLServerConceptsandTerminologyDataTypesLimitsOperatorsBuilt-InFunctionsDifferencesinSQLSyntaxDifferencesinSQLSemanticsDifferencesinManagingDatabasesDifferencesinManagingDatabaseObjectsDifferencesinManagingUsersDifferencesinIntegrationwithMSADO,RDO,etc.MiscellaneousDifferencesSeeAlsoDetailsofTips:OracleTipsSQLTips
ThissectioncontainstipsonstandardSQL(StructuredQueryLanguage)statementsinOracle.
SELECT*andmore
LastUpdated:6/6/1999
Appliesto:Oracle7.3,8(andprobablyearlierversions)

Toselectallcolumnsofatable:

select*fromtable

However,toselectallrealcolumns,plusapseudo-columnlike"user":

selecttable.*,userfromtable

Thefollowingdoesnotwork:

select*,userfromtable

--Fred
MaterializedView
LastUpdated:1/7/2002
Appliesto:Oracle8+

Oracle8iintroducedanewfeaturecalleda"materializedview".Youdefineitjustlikeanyotherview,exceptthatyouaddthekeywordMATERIALIZED:

CREATEMATERIALIZEDVIEWview_name

Amaterializedviewislikeacombinationofatableandaview.Likeaview,itisdefinedasalogicalviewintothedataofoneormoretables.Whenyouupdatethetables,subsequentqueriesoftheviewseetheupdateddata.However,likeatable,itsdataisstoredinthedatabase.Also,likeatable,itisfasterifyoudefineindexesforit.

Aregularviewisstoredasamappingofdatafromtables.Whenyoumodifythedatainthetables,theviewiscompletelyignored.Whenyouaccesstheview,itjoinsthedatacurrentlyinthetables,andreturnsthedatayourequested.Amaterializedviewisstoredassuchamappingalongwithacopyoftheactualdatafromthetables.Whenyoumodifythedatainthetables,theviewscopyofthedataisalsoupdated.Whenyouaccesstheview,thedataisdrawndirectlyfromthecopy.

Thusamaterializedviewmakestableupdatesalittleslower,butmakesviewqueriesmuchfaster.Italsoconsumesadditionalspaceinthedatabase.

Youcouldaccomplishthesameeffectbydefininganadditionaltableinsteadoftheview,andusingtriggersonthecomponenttablestoupdateiteachtimetheyarechanged.However,usingamaterializedviewismoreconvenient,moreefficient,andclearertothenextpersonwhohastomaintainyourdatabase.

ThankstoAndyGlickforsendingmeasampleofamaterializedviewfromhisapplication!

--Fred
PL/SQLTips
ThissectioncontainstipsonPL/SQLstatements--theOracle"procedurallanguage"supersetofSQLthatyouusetowritestoredprocedures.
SQLNavigatorTips
ThissectioncontainstipsontheSQLNavigatortoolbyQuestSystems.ItisagraphicalfrontendtotheOracledatabase,allowingyoutocreate,delete,view,andmodifyallOracleobjects:tables,views,storedprocedures,etc.
SeeAlso
LastUpdated:6/6/1999
Appliesto:Oracle7.3+

ThefollowingaregoodsourcesofinfoaboutOracle:
Koch,George,andKevinLoney.Oracle8,TheCompleteReference.BerkeleyCA:ForOraclePressbyOsborneMcGraw-Hill,1997.ISBN0-07-882396-X.
ThisbookincludesintroductorydatabaseconceptsaswellasacompletereferencetoOracleSQLandPL/SQLstatements.ThecompanionCDcontainsacompletecopyofthebook,soyoucanreaditon-line,searchit,etc.AnyoftheOReillybooks.IvebeenveryimpressedbyalloftheOReillybookssincemyearlyUnixandX-Windowsdaysinthe80s,andtheyhaveacompleteseriesonOracle,coveringPL/SQL,thestandardpackages,etc.
--Fred
MSSQLServerTipsSQLTips
ThissectioncontainstipsonSQL(StructuredQueryLanguage)statementsinMSSQLServer.
DynamicSQLinaStoredProcedure
LastUpdated:2/7/1999
Appliesto:MSSQLServer6.5+

AtypicaltradeoffforadatabaseapplicationisdynamicSQL(SQLcommandsembeddedintheapplication--forflexibility)vs.storedprocedures(pre-compiledSQLproceduresstoredinthedatabaseandinvokedbynamefromtheapplication--forspeedandcontroloverwhatSQLstatementsgetexecuted).However,youcanhavethebestofbothworldsbyusingdynamicSQLinsideyourstoredprocedures.Inastoredprocedure,youcanusetheEXECstatementtoexecuteastringofSQLstatementsthatyoubuiltdynamicallyinthestoredprocedureorreadfromthedatabaseoranyotherdatasource.

ThankstoSteveRhoadsforthistip.

--Fred
SQLEnterpriseManagerTips
ThissectioncontainstipsontheSQLEnterpriseManagertool.Itisagraphicalfrontendtothedatabase,allowingyoutocreate,delete,view,andmodifyallMSSQLServerobjects:tables,views,storedprocedures,etc.
KeyboardShortcuts
LastUpdated:6/20/1999
Appliesto:MSSQLServer7.0

HereisalistofsomeofthemoreusefulshortcutkeysinSQLEnterpriseManager.
KeyFunctionF1HelponSQLEnterpriseManagerShift-F1HelponsyntaxofcurrentSQLstatementCtrl-EExecuteselectedtextinQueryAnalyzerCtrl-RHide/showresultspaneinQueryAnalyzer
Obviously,thislistisfarfromcomplete.Pleasefeelfreetomailmeyourfavoriteshortcuts.Illaddtothislistastimepermits.

Seealso:WindowsShortcutKeys

--Fred
SQLGeneratingSQL
LastUpdated:2/7/1999
Appliesto:MSSQLServer6.5+

Toautomatetediousdatabasemaintenancechores,youcanuseSQLstatementstogenerateSQLstatementsthatdoyourmaintenanceforyou.Forexample,tochangethepermissionsonallstoredproceduresinadatabase,youcanuseaSELECTstatementlike:

SELECTGRANTEXECUTEON+name+TOPUBLICGOFROMsysobjectsWHEREtype=P

TheoutputofthisSELECTstatementisaseriesofalternatingGRANTandGOstatements,onepairperstoredprocedures,forallstoredproceduresinthedatabase.Thenyoucopythatoutputasyournextsetofcommandsandexecuteit.

Note:BesuretoleavethelinebreakbeforethewordGO.Itisrequiredtostartonanewline,aftertheGRANTstatement.

ThankstoSteveRhoadsforthistip.

--Fred
SeeAlso
LastUpdated:6/6/1999
Appliesto:MSSQLServer6.5+

ThefollowingaregoodsourcesofinfoaboutMSSQLServer:
MSSQLServerbooksontheMSDNLibraryCD.
--Fred
DifferencesBetweenOracleandMSSQLServerConceptsandTerminology
LastUpdated:4/24/2001
Appliesto:Oracle7.3+,MSSQLServer6.5+

ThefollowingtableshowssomedifferencesinconceptsandterminologybetweenOracleandMSSQLServer:
Concept/TermOracleMSSQLServerDatabaseenginedatabasedatabaseserverDatabase(collectionoftables)schemadatabaseRoles/GroupsrolesgroupsDatabaseadminstratoraccount,databaseownerdbasa,dboDataaboutthedatabaseDataDictionary
-oneperserverDatabaseCatalog
-oneperdatabase
"master"database
-oneperserverBlocksandextentsblocksandextentspagesandextentsNetworksoftwareSQL*NetNet-libraryDatastreamprotocolTransparentNetworkSubstrate(TNS)TabularDataStream(TDS)Casesensitivityofnamesoftables,columns,etc.case-insensitivedependsoncharactersortorder,defaultiscase-insensitiveSynonymssupportednotsupportedReadonlytransactionsupportednotsupported
--Fred
DataTypes
LastUpdated:6/6/1999
Appliesto:Oracle7.3+,MSSQLServer6.5+

ThefollowingtableshowsthecorrespondingdatatypesinOracleandMSSQLServer:
DataTypeOracleMSSQLServerFixedLengthStringCHAR(n)
-limit2KBCHAR(n),CHARACTER(n)
-limit255(6.5)
-limit8KB(7.0)VariableLengthStringVARCHAR2(n),VARCHAR(n)
-limit4KBinacolumn
-limit32KBinavariable
-VARCHARisobsolete
VARCHAR(n),CHARVARYING(n),CHARACTERVARYING(n)
-limit255(6.5)
-limit8KB(7.0)IntegerINTEGER,INTEGER(n),SMALLINTINTEGER(4bytes),
INT(4bytes),
SMALLINT(2bytes),
TINYINT(1byte),
BIT(1bit)FixedPointNUMBER,NUMBER(n),NUMBER(n,d),
FLOAT,FLOAT(n),FLOAT(n,d)NUMERIC,NUMERIC(n),NUMERIC(n,d),
DECIMAL,DECIMAL(n),DECIMAL(n,d),
DEC,DEC(n),DEC(n,d),
MONEY,SMALLMONEYFloatingPointDECIMALFLOAT,FLOAT(n),DOUBLEPRECISION,
REAL,DateDATEDATETIME,SMALLDATETIME,TIMESTAMP
-TIMESTAMPauto-updatedBinaryRAW(n)
-limit255bytesBINARY(n),VARBINARY(n),BINARYVARYING(n)
-limit255(6.5)
-limit8KB(7.0)LargeStringLONG,LONGVARCHAR
-limit2GB
-limitonepertablerow
CLOB
-limit4GBTEXT
-limit2GBLargeBinaryLONGRAW
-limit2GB
-limitonepertablerow
BLOB
-limit4GBIMAGE
-limit2GBMulti-bytecharsNCHAR(n)
NVARCHAR(n)
NCLOB
-samelimitsasCHAR,VARCHAR,CLOBNCHAR(n),NATIONALCHAR(n),NATIONALCHARACTER(n)
NVARCHAR(n),NATIONALCHARVARYING(n),NATIONALCHARACTERVARYING(n)
NTEXT,NATIONALTEXT
-samelimitsasCHAR,VARCHAR,TEXTOSFileBFILE<notsupported>RowIdentifierimplicitROWIDcolumn(useanIDENTITYcolumn)SecureOSLabelMLSLABEL,RAWMLSLABEL<notsupported>128-bitUniqueNumber
(UUID,GUID)<notsupported>UNIQUEIDENTIFIER(version7.0only)
--Fred
Limits
LastUpdated:6/14/2000
Appliesto:Oracle7.3+,MSSQLServer6.5+

ThefollowingtableshowsdifferencesinlimitsofOracleandMSSQLServer:
DescriptionOracleMSSQLServerColumnspertable1000250(6.5)
1024(7.0)Rowsizeunlimited1962bytes(6.5)
8060bytes(7.0)
-includespointers,butnotdata,forTEXTandIMAGEcolumnsLONGandLONGRAWcolumnsperrow1(mustbelastcolumn)unlimited(16-bytepointerper)LOB,TEXT,andIMAGEcolumnsperrowunlimited(16-bytepointerper)unlimited(16-bytepointerper)Clusteredindexespertable11Non-clusteredindexespertableunlimited249Columnsperindex1616Indexrowsize2Kbytes900bytesIdentifierLength30chars30chars(6.5)
128chars(7.0)TablesperSELECTunlimited16(6.5)
256(7.0)Sourcecodeperstoredprocedure64KB(6.5)
250MB(7.0)Datatypelimits(seeDataTypes)
--Fred
Operators
LastUpdated:6/7/1999
Appliesto:Oracle7.3+,MSSQLServer6.5+

MostoperatorsarethesameinOracleandMSSQLServer.Herearesomethatdiffer:
DescriptionOracleMSSQLServerStringconcatenationstring1||string2string1+string2
--Fred
Built-InFunctions
LastUpdated:6/7/1999
Appliesto:Oracle7.3+,MSSQLServer6.5+

OracleandMSSQLServeroffermanyofthesamebuilt-infunctions.Forexample,theybothofferABS,EXP,ROUND,UPPER,LOWER,AVG,COUNT,SUM,ASCII,etc.Thefollowingtableshowssomeofthecorrespondingfunctionsthatdonthavethesamename.Foramorecompletelist,see"MigratingOracleApplicationstoSQLServer"
DescriptionOracleMSSQLServerSmallestinteger>=nCEILCEILINGModulusMOD%TruncatenumberTRUNC<none>MaxorminnumberorstringinlistGREATEST,
LEAST<none>TranslateNULLtonNVLISNULLReturnNULLiftwovaluesareequalDECODENULLIFStringconcatenationCONCAT(str1,str2)str1+str2ConvertASCIItocharCHRCHARCapitalizefirstlettersofwordsINITCAP<none>FindstringinstringINSTRCHARINDEXFindpatterninstringINSTRPATINDEXStringlengthLENGTHDATALENGTHPadstringwithblanksLPAD,
RPAD<none>TrimleadingortrailingcharsotherthanblanksLTRIM(str,chars),
RTRIM(str,chars)<none>ReplacecharsinstringREPLACESTUFFConvertnumbertostringTO_CHARSTR,CASTConvertstringtonumberTO_NUMBERCASTGetsubstringfromstringSUBSTRSUBSTRINGCharforchartranslationinstringTRANSLATE<none>DateadditionADD_MONTHor+DATEADDDatesubtractionMONTHS_BETWEENor-DATEDIFFLastdayofmonthLAST_DAY<none>TimezoneconversionNEW_TIME<none>NextspecifiedweekdayafterdateNEXT_DAY<none>ConvertdatetostringTO_CHARDATENAME,CONVERTConvertstringtodateTO_DATECASTConvertdatetonumberTO_NUMBER(TO_CHAR(d))DATEPARTDateroundROUNDCONVERTDatetruncateTRUNCCONVERTCurrentdateSYSDATEGETDATEConverthextobinaryHEXTORAWCASTConvertbinarytohexRAWTOHEXCONVERTIfstatementinanexpressionDECODECASE...WHEN
orCOALESCEUsersloginidnumberornameUID,USERSUSER_ID,SUSER_NAMEUsersdatabaseidnumberornameUID,USERUSER_ID,USER_NAMECurrentuserUSERUSER
--Fred
DifferencesinSQLSyntax
LastUpdated:3/21/2001
Appliesto:Oracle7.3+,MSSQLServer6.5+

ThefollowingtableshowsthedifferentsyntaxusedinOracleandMSSQLServerforthesameSQLoperations:
DescriptionOracleMSSQLServerLeftOuterJoinWHEREcolumn1=column2(+)FROMtable1LEFTOUTERJOINtable2ONtable1.column1=table2.column2

Note:Thefollowingsyntaxisalsosupported,butisnolongerrecommended:
WHEREcolumn1*=column2RightOuterJoinWHEREcolumn1(+)=column2FROMtable1RIGHTOUTERJOINtable2ONtable1.column1=table2.column2

Note:Thefollowingsyntaxisalsosupported,butisnolongerrecommended:
WHEREcolumn1=*column2FullOuterJoinFROMtable1FULLOUTERJOINtable2ONtable1.column1=table2.column2SELECTwithoutFROMSELECThelloworldFROMDUALSELECThelloworldSELECTdataintoatableCREATETABLEASSELECT...SELECT...INTOIntersectionof2SELECTSSELECT...INTERSECTSELECT...SELECT...WHEREEXISTS(SELECT...)Subtractionof2SELECTSSELECT...MINUSSELECT...SELECT...WHERENOTEXISTS(SELECT...)INSERTintoaJOININSERTINTOSELECT...CreateaVIEWandINSERTINTOit.UPDATEdatainaJOINUPDATESELECT...CreateaVIEWandINSERTINTOit.UPDATEonetablebasedoncriteriainanothertable<notsupported>UPDATEtableFROM...DELETErowsfromonetablebasedoncriteriainanothertable<notsupported>DELETEFROMtableFROM...DROPacolumnfromatable<notsupporteduntilOracle8i>ALTERTABLEtable_nameDROPCOLUMNcolumn_nameReadonlyVIEWCREATEVIEW...WITHREADONLYGRANTSELECT...SavepointSAVEPOINTSAVETRANSACTIONTablelockLOCKTABLE...INSHAREMODESELECT...table_name(TABLOCK)ExclusivetablelockLOCKTABLE...INEXCLUSIVEMODESELECT...table_name(TABLOCKX)ReservingindexspacePCTFREE=0FILLFACTOR=100DeclaringalocalvariableDECLAREvarnametype;DECLARE@varnametypeInitializingalocalvariableDECLAREvarnametype:=value;<notsupported>DeclaringaconstantDECLAREvarnameCONSTANTtype:=value;<notsupported>Assigningtoavariablevarname:=value
SELECTvalueINTOvarnameSET@varname=value
SELECT@varname=valueAssigningtoavariablefromacursorFETCHcursornameINTOvarnameFETCHNEXTFROMcursornameINTOvarnameDeclaringacursorCURSORcurname(params)
ISSELECT...;DECLAREcurnameCURSORFORSELECT...IfstatementIF...THEN
ELSIF...THEN
ELSE
ENDIFIF...
BEGIN...END
ELSEBEGIN...ENDWhileloopWHILE...LOOP
ENDLOOPWHILE...
BEGIN...ENDOtherloopsFOR...ENDLOOP
LOOP...ENDLOOP<notsupported>LoopexitEXIT,EXITWHENBREAK,CONTINUEPrintoutputDBMS_OUTPUT.PUT_LINEPRINTRaiseerrorRAISE_APPLICATION_ERRORRAISERRORStatementterminatorSemi-colon(;)<nonerequired>
ThankstoTomJohnstonforcatchingamistakeinthistip.IhadtheFROMDUALinthewrongcolumn.

--Fred
DifferencesinSQLSemantics
LastUpdated:6/6/1999
Appliesto:Oracle7.3+,MSSQLServer6.5+

ThefollowingtableshowssomesemanticdifferencesbetweenOracleandMSSQLServer:
DescriptionOracleMSSQLServerCommitExplicitCOMMITstatementrequiredAutomaticcommitunlessSETIMPLICIT_TRANSACTIONSONReadinguncommitteddataDatabasedoestemporaryinternalrollbacktoreconstructmostrecentlycommitteddataforreader.Dependingonoptions,readerasallowedtoreaduncommitteddata,orisforcedtowaitforwritertocommitorrollback.ReleasingcursordataCLOSECURSORreleasesalldata.Youcantre-open.CLOSECURSORdoesnotreleasedata.YoumustexplicitlycallDEALLOCATECURSOR.Untilthen,youcanre-openthecursor.ImplicitdataconversioninastatementlikethefollowingwherevcisacolumnoftypeVARCHAR2:
SELECT*FROMperson
WHEREvc=123

Aseachrowisfetchedfromthetable,anattemptismadetoconvertittoanumberforthecomparisonwith123.Ifanyrowcontainsavaluethatcannotbeconvertedtoanumber,aruntimeerroroccurs.Thenumber123isconvertedtothestring123once,andthenthedataisfetchedfromthetable.Ifanyrowcontainsavaluethatcannotbeconvertedtoanumber,itsimplydoesntmatch123andisskippedwithoutanyerror.ConversiontoNULLSettingaVARCHAR2columnto(theemptystring)makesitNULL.SettingaVARCHARcolumntomakesittheemptystring(notNULL).
--Fred
DifferencesinManagingDatabases
LastUpdated:6/6/1999
Appliesto:Oracle7.3+,MSSQLServer6.5+

ThefollowingtableshowssomedifferencesinhowdatabasesaremanagedinOracleandMSSQLServer:
DescriptionOracleMSSQLServerModeldatabaseNomodeldatabaseNewlycreateddatabasesinheritcharacteristics(users,etc.)fromthespecialdatabasenamed"model".
--Fred
DifferencesinManagingDatabaseObjects
LastUpdated:6/6/1999
Appliesto:Oracle7.3+,MSSQLServer6.5+

Thefollowingtableshowssomedifferencesinhowdatabaseobjects(tables,views,storedprocedures,etc.)aremanagedinOracleandMSSQLServer:
DescriptionOracleMSSQLServerFullyqualifiedname[schema.]table
[schema.]view[[[server.][database].][owner].]table
[[[server.][database].][owner].]viewTemptablesPre8i:Temporarytablesmustbedeletedexplicitly
8i+:CREATEGLOBALTEMPORARYTABLE
#table--Anytablenamedstartingwithapoundsign(#)isautomaticallydeletedwhentheuserlogsoffortheprocedureends.
##table--Sameasabove,exceptthatthetableisaccessibletootherusers.Re-creatinganobjectCREATEORREPLACE...DROP...
CREATE...CreateviewbeforedependenttablesCREATEFORCEVIEWNotsupported.Tablesusedbyviewmustexistbeforeviewcanbecreated.
--Fred
DifferencesinManagingUsers
LastUpdated:6/6/1999
Appliesto:Oracle7.3+,MSSQLServer6.5+

ThefollowingtableshowssomedifferencesinhowusersaremanagedinOracleandMSSQLServer:
DescriptionOracleMSSQLServerMembershipingroupsEachusercanbeamemberofanynumberofgroups.Eachusercanbeamemberofonlyonegroupotherthan"public".
--Fred
DifferencesinIntegrationwithMSADO,RDO,etc.
LastUpdated:6/6/1999
Appliesto:Oracle7.3+,MSSQLServer6.5+

ThefollowingtableshowsthedifferenttechniquesusedinOracleandMSSQLServertointeractwithMSADO,RDO,etc.:
DescriptionOracleMSSQLServerReturnarecordsettothecallerReturnahandletoacursor.
Formoreinfo:SeeMSKBarticleQ174679.SELECTwithnoINTOclause;
MultiplesuchSELECTsreturnmultiplerecordsets
--Fred
MiscellaneousDifferences
LastUpdated:6/6/1999
Appliesto:Oracle7.3+,MSSQLServer6.5+

ThefollowingtableshowsmiscellaneousdifferencesbetweenOracleandMSSQLServer:
DescriptionOracleMSSQLServerGenerateuniquenumbersCREATESEQUENCEIDENTITYcolumnofatableCascadedDELETEDELETECASCADE...(usetriggers)Callauser-definedfunctionfromaSQLstatement(ascolumnofSELECTorexpressioninWHEREclause)supportednotsupported
--Fred
SeeAlso
LastUpdated:3/3/2001
Appliesto:Oracle7.3+,MSSQLServer6.5+

ThefollowingaregoodsourcesofinfoaboutdifferencesbetweenOracleandMSSQLServer:
Bowman,JudithS.,SandraL.Emerson,andMarcyDarnovsky.ThePracticalSQLHandbook.Addison-WesleyPublishingCompany,1993.ISBN0-201-62623-3.
ThisbookgivesagoodintroductiontoSQL,withaslightemphasisonSybase,butwithausefulsummaryinthebackofthesyntaxforeachoftheSQLstatements(SELECT,INSERT,UPDATE,DELETE,CREATE,DROP,GRANT,REVOKE,etc.)foreachofthemajordatabases(Oracle,Sybase,DB2,Informix,Ingres,etc.)Thebookpre-datesMSSQLServer,buttheSybaseinfoisagoodapproximationsinceMSSQLServerisaderivativeofSybase.
"MigratingOracleApplicationstoSQLServer"onMSDNCD,andatMSTechNetWebsite:
http://www.microsoft.com/TechNet/sql/Tools/Sqldevkt/ORCL2SQL.asp
Microsoftclearlyintendedthistobeusedinonedirectiononly,butIveuseditquitesuccessfullytotranslatemySQLServerknowledgetoOracleaswell.

最近由权威调查机构Evans数据公司进行的一项调查显示，MySQL在过去两年已经获得了25%的市场份额。该调查公司还预测，相比其他的开源数据库和闭源数据库。

SQL语言是学习所有数据库产品的基础，无论你是做数据库管理还是做数据库开发都是这样。不过具体学习的侧重点要看你将来做哪一块，如果是做数据库管理（DBA），侧重点应该放在SQLServer的系统管理上.

习惯敲命令行的朋友可能会爽一些。但是功能有限。适合机器跑不动SQLServerManagementStudio的朋友使用。

以前的DTS轻盈简单。但是现在的SSIS虽然功能强大了很多，但是总是让人感觉太麻烦。看看论坛中询问SSIS的贴子就知道。做的功能太强大了，往往会有很多用户不会用了

无法深入到数据库系统层面去了解和探究

大侠们有推荐的书籍和学习方法写下吧。

原理很简单，对要求长时间计算某一时间点的报表生成和防用户操作错误很有帮助。但是比起Oracle10g的闪回技术还是细粒度不够。可惜！

如果处理少量数据,比如几百条记录的数据,我不知道这两种情况哪个效率更高,如果处理大量数据呢?比如有表中有20万条记录.