多项选择题
A.It fails if any existing row violates the constraint.
B.It does not validate the existing data in the table.
C.It enables the constraint to be enforced at the end of each transaction.
D.It prevents insert， update， and delete operations on the table while the constraint is in the process of being enabled.
单项选择题 Your database is started by using the server parameter file （SPFILE）. You issued this command to change the value of the LOG_BUFFER initialization parameter： ALTER SYSTEM SET LOG_BUFFER=24M SCOPE=BOTH What would be the outcome of this command？（）
单项选择题 You are using flat files as the data source for one of your data warehousing applications. You plan to move the data from the flat file structures to an Oracle database to optimize the application performance. In your database you have clustered tables. While migrating the data， you want to have minimal impact on the database performance and optimize the data load operation. Which method would you use to load data into Oracle database？（）
单项选择题 YourdatabaseisinNOARCHIVELOGmodeandalogswitchhappensevery20minutes.OnThursdaymorning，mediafailureresultedincorruptionofadatafilebelongingtotheTOOLStablespace.BackupsaretakenoneverySunday.Whatwouldyoudointhissituation？（）