天天向上
日常的一些小筆記
博文
(2014-08-03 09:15:54)
surrogatekey,uniqueidentifier,notfromtheapplicationdataitself[閱讀全文]
(2014-07-28 17:05:11)
don'tuse*inthequery(*isanti-patterninquery,whichwillcreatemuchworkfortheserver)
don'tomitcolumnlistininsertion(thinkwhatifanewcolumnwillbeaddedlater)
...
AdhocisaLatinphrasemeaning"forthis".Itgenerallysignifiesasolutiondesignedforaspecificproblemortask,non-generalizable,andnotintendedtobeabletobeadaptedtootherpurposes.Commonexamplesareorganizations,committees,andcommissionscr...[閱讀全文]
don'tomitcolumnlistininsertion(thinkwhatifanewcolumnwillbeaddedlater)
...
AdhocisaLatinphrasemeaning"forthis".Itgenerallysignifiesasolutiondesignedforaspecificproblemortask,non-generalizable,andnotintendedtobeabletobeadaptedtootherpurposes.Commonexamplesareorganizations,committees,andcommissionscr...[閱讀全文]
(2014-07-28 09:33:04)
sp_help
sp_helpindex
sp_helptext
sysobjects
OBJECT_ID()
syscomments
sys.sql_modules
GO
ONLYinSSMS,abatchseparator/terminator,youcanchangeittowhateveryouwant.
ItisusedtogroupSQLcommandsintobatcheswhicharesenttotheservertogether.
CREATEDEFAULT,CREATEFUNCTION,CREATEPROCEDURE,CREATERULE,CREATETRIGGER,andCREATEVIEWstatementscannotbecombinedwithotherstatementsinab...[閱讀全文]
sp_helpindex
sp_helptext
sysobjects
OBJECT_ID()
syscomments
sys.sql_modules
GO
ONLYinSSMS,abatchseparator/terminator,youcanchangeittowhateveryouwant.
ItisusedtogroupSQLcommandsintobatcheswhicharesenttotheservertogether.
CREATEDEFAULT,CREATEFUNCTION,CREATEPROCEDURE,CREATERULE,CREATETRIGGER,andCREATEVIEWstatementscannotbecombinedwithotherstatementsinab...[閱讀全文]
(2014-07-28 08:54:21)
Wordsstartingwithconsonant:
movetheconsonanttotheendoftheword,thenadd'ay'attheend
the-->ethay,cat-->atcay
Wordsstartingwithvowel:
add'way'attheend
eat-->eatway,and-->andway
Haveaniceday!
-->Avehayawayicenayayday!
Areyoulookingforajob?
-->Arewayouyayookinglayorfayawayobjay?
Oinkoink
-->Oinkwayoinkway
movetheconsonanttotheendoftheword,thenadd'ay'attheend
the-->ethay,cat-->atcay
Wordsstartingwithvowel:
add'way'attheend
eat-->eatway,and-->andway
Haveaniceday!
-->Avehayawayicenayayday!
Areyoulookingforajob?
-->Arewayouyayookinglayorfayawayobjay?
Oinkoink
-->Oinkwayoinkway
(2014-07-28 08:20:38)
Owneristhecreater.
Useristheuseraccountunderacertaindb.
schemaisacontainerfororganizingtheobjects.
schemasvsusers
dbo--1.dbowner;2.useraccount:dbo;3.schema:dbo
dbo.tblPerson--heredboisreferredasthe'SCHEMAdbo',not'userdbo'or'ownerdbo'
proofschema.tblxxx:
Sincetheobjectsarenottiedtoanyuseraccounts,youdonothavetoworryaboutchangingtheownerofobjectswhenanaccountistoberemoved...[閱讀全文]
Useristheuseraccountunderacertaindb.
schemaisacontainerfororganizingtheobjects.
schemasvsusers
dbo--1.dbowner;2.useraccount:dbo;3.schema:dbo
dbo.tblPerson--heredboisreferredasthe'SCHEMAdbo',not'userdbo'or'ownerdbo'
proofschema.tblxxx:
Sincetheobjectsarenottiedtoanyuseraccounts,youdonothavetoworryaboutchangingtheownerofobjectswhenanaccountistoberemoved...[閱讀全文]
(2014-07-22 21:30:01)
SSISDBcatalog
deployanSSISprojectintoSSISDB(3ways)
datatools-BIDS(inearlyversion)
DTS(inearlierversion)-->SSIS(08orlaterversion)(tasks/importorexport...)
connectiontype(OLEDB,ODBC)
stagingtable
Hibernateinsert
bulkinsertwithbulkadmin
con:
popularinlegacysystem,SP'slogicisstillonDBitself.
SPincreasesthedifficultyofdeploymentandmaintenance,causeshigercoupling....[閱讀全文]
deployanSSISprojectintoSSISDB(3ways)
datatools-BIDS(inearlyversion)
DTS(inearlierversion)-->SSIS(08orlaterversion)(tasks/importorexport...)
connectiontype(OLEDB,ODBC)
stagingtable
Hibernateinsert
bulkinsertwithbulkadmin
con:
popularinlegacysystem,SP'slogicisstillonDBitself.
SPincreasesthedifficultyofdeploymentandmaintenance,causeshigercoupling....[閱讀全文]
(2014-07-22 07:54:49)
文檔管理文檔、電子表格、圖形和影象掃描文檔的存儲、分類和檢索。每個文本具有一個類似於索引卡的記錄，記錄了諸如作者、文檔描述、建立日期和使用的應用程序類型之類的信息。這些文檔一般歸檔在較便宜的磁帶上，必要時歸檔在可讀寫的光盤上。[閱讀全文]
(2014-07-20 21:23:34)
BuildHadoopinAzure.HDInsightmakesApacheHadoopavailableasaserviceinthecloud.
[閱讀全文]
[閱讀全文]
(2014-07-19 09:32:50)
IPO,InitialPublicOffering,acorporation'sfirstoffertosellstocktothepublic
Cloudera(halfboughtbyIntel)>MapR(recentlyfundedbyGoogleCapitalandQualcomm)>Hortonworks(fundedbyGoogleVenture)??
GoogleCapital:biggerfundforlatestagestartups
GoogleVenture:smallerfundforearlystagestartups
AWS
EC2AmazonElasticCloudCompute,providesscalablevirtualprivateserversusingXen.
S3AmazonSimpleStora...[閱讀全文]
Cloudera(halfboughtbyIntel)>MapR(recentlyfundedbyGoogleCapitalandQualcomm)>Hortonworks(fundedbyGoogleVenture)??
GoogleCapital:biggerfundforlatestagestartups
GoogleVenture:smallerfundforearlystagestartups
AWS
EC2AmazonElasticCloudCompute,providesscalablevirtualprivateserversusingXen.
S3AmazonSimpleStora...[閱讀全文]
(2014-07-18 07:24:35)
normalization/denormaliztion
fact/dimension/base
staging
cursor(performacekiller)
CTE
WITH
Hierarchicaldata
HierarchyIDdatatype
recursivetree
windowfunction
analyticalfunction
aggregatefunction
rankingfunction
performancetuning(SETNOCOUNTON)
randomdataordatasample(TOPn,TABLESAMPLE(nROWS),ORDERBYNEWID(),CHECKSUM(NEWID())
CASE
IDENTITYA...[閱讀全文]
fact/dimension/base
staging
cursor(performacekiller)
CTE
WITH
Hierarchicaldata
HierarchyIDdatatype
recursivetree
windowfunction
analyticalfunction
aggregatefunction
rankingfunction
performancetuning(SETNOCOUNTON)
randomdataordatasample(TOPn,TABLESAMPLE(nROWS),ORDERBYNEWID(),CHECKSUM(NEWID())
CASE
IDENTITYA...[閱讀全文]
