多项选择题
Which two statements are true about the primary key constraint in a table？ （）
A.It is not possible to disable the primary key constraint.
B.It is possible to have more than one primary key constraint in a single table.
C.The primary key constraint can be referred by only one foreign key constraint.
D.The primary key constraint can be imposed by combining more than one column.
E.The non-deferrable primary key constraint creates an unique index on the primary key column if it is not already indexed.
相关考题
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单项选择题
Youareusingflatfilesasthedatasourceforoneofyourdatawarehousingapplications.YouplantomovethedatafromtheflatfilestructurestoanOracledatabasetooptimizetheapplicationperformance.Inyourdatabaseyouhaveclusteredtables.Whilemigratingthedata，youwanttohaveminimalimpactonthedatabaseperformanceandoptimizethedataloadoperation.WhichmethodwouldyouusetoloaddataintoOracledatabase？（）
A.use the external table population
B.use the Oracle Data Pump export and import utility
C.use the conventional path data load of SQL*Loader utility
D.use the direct path data load of Oracle export and import utility -
单项选择题
Inyourdatabase，theSTATISTICS_LEVELinitializationparameterissettoBASIC.Whatistheimpactofthissetting？（）
A.The optimizer statistics are collected automatically.
B.Only the timed operating system （OS） statistics and plan execution statistics are collected.
C.The Oracle server dynamically generates the necessary statistics on tables as part of query optimization.
D.The snapshots for the Automatic Workload Repository （AWR） are not generated automatically.
E.Snapshots cannot be collected manually by using DBMS_WORKLOAD_REPOSITORY PACKAGE. -
单项选择题
Youwanttomonitorandcontroltheresourceusagebysessions.Youwanttobewarnedautomaticallywhenmorethan100sessionsareopenedwithyourdatabase.Whatactionwouldyoutaketoachievethis？（）
A.Use the Database Resource Manager.
B.Set the limits in the profiles used by users.
C.Modify the SESSIONS initialization parameter.
D.Set the warning threshold for the Current Logons Count metric.
