???????:
????1.????????
????2.???????select??????
???????:
????1.??Щ??????????WITH (NOLOCK)??SQL???Ч?????????33%??
????2.????????inner join ???
???????: ?????????????????????????????????????????????????????????????????????????????????????????????????????????????
???????????:
?????????SQL????Ч??????????????????????(index)????????????????index??????????????????SQL Command????????м????WITH (NOLOCK)???????????????????????????????LOCK???????????????Ч???
????????????????????????WITH (NOLOCK)??SQL SELECT?п???????Dirty Read(???)??
???????磺
????SELECT  COUNT(UserID)
????FROM    EMPLOYEE WITH (NOLOCK)
????JOIN WORKING_GROUP WITH (NOLOCK)
????ON EMPLOYEE.UserID = WORKING_GROUP.UserID
???????????SELECT?????JOIN??SELECT?????????????????DELETE??INSERT??UPDATE??Щ???transaction???????????…
??????Щ??????????WITH (NOLOCK)??SQL???Ч?????????33%??
????????WITH (NOLOCK)??????SQL Server??????????SELECT??????????????table??transaction lock???????Ч???????????????????????????????Lock???????????????(????Dead Lock)??
?????? ?????????????WITH (NOLOCK)????????table??transaction lock?????????Щ????????????phase????(???????table??transaction????-->???????)??WITH (NOLOCK)?????????????process???????????…
?????????????????????NoLock??????????????Щ????????????н???????????????????????????transaction???????????????????????WITH (NOLOCK)??ú????????
??????????迼??transaction??WITH (NOLOCK)????????????ο???
?????1??WITH ( < table_hint > )
???????????????????????衢???????????
?????????????????????????????????????????????
?????2??WITH (NOLOCK)????READ UNCOMMITTED