YouexecutethiscommandtodroptheITEMtable,whichhastheprimarykeyreferredintheORDERtable:SQL>DROPTABLEscott.itemCASCADECONSTRAINTSPURGE;Whichtwostatementsaretrueabouttheeffectofthecommand()
A. NoflashbackispossibletobringbacktheITEMtable.
B. TheORDERtableisdroppedalongwiththeITEMtable.
C. ThedependentreferentialintegrityconstraintsintheORDERtablearedisabled.
D. ThedependentreferentialintegrityconstraintsintheORDERtableareremoved.
E. ThetabledefinitionoftheITEMtableandassociatedindexesareplacedintherecyclebin.
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WhichtwostatementsaretrueregardingtheUSINGandONclausesintablejoins?()
A. BothUSINGandONclausescanbeusedforequijoinsandnonequijoins
B. AmaximumofonepairofcolumnscanbejoinedbetweentwotablesusingtheONclause
C. TheONclausecanbeusedtojointablesoncolumnsthathavedifferentnamesbutcompatibledatatypes
D. TheWHEREclausecanbeusedtoapplyadditionalconditionsinSELECTstatementscontainingtheONortheUSINGclause
Inyourdatabaseinstance,theusersessionsareconnectedtothedatabaseserverfromtheremotemachines.Youwanttoachievethefollowingfortheseusers:1:Theuseraccountmustbelockedafterfourunsuccessfulloginattempts.PASSWORD_LOCK_TIME2:Theusermustbepromptedtochangethepasswordatregularintervals.PASSWORD_LIFE_TIME3:Theusermaynothavemorethanthreesimultaneoussessions.SESSIONS_PER_USER4:Theusersessionmustautomaticallybeloggedoffifmorethan10minuteselapsedtimeused.CONNECT_TIMEHowwouldyouaccomplishtheabove()
A. byassigningprofilesfortheusers
B. byimplementingFine-GrainedAuditing(FGA)
C. bygrantingasecureapplicationroletotheusers
D. byimplementingtheDatabaseResourceManagerplan
在航天科学研究发展,人未正式乘坐航天器遨游天空之前,先用其它一些动物做实验,通过考察鼠、狗、兔等动物的身体在太空中能经受长时间失重的考验,于是得出结论:“一切动物的身体在太空中都能经受长时间的失重考验。”这是属于()推理。
A. 必然性
B. 假言
C. 完全归纳
D. 简单枚举归纳
排中律的适用范围是()。
A. 反对关系
B. 矛盾关系
C. 差等关系
D. 下反对关系