单项选择题 You have two database servers SEMP and SACCT. The database in the SEMP server maintains the employeeinformation and the database in the SACCT server maintains the accounts payable information. The employeessubmit the expense reports to the accounts payable department. A user of the accounts payable databasewants to extract the employee information from the database in the SEMP server for cross-verification.  Whichschema object enables the user to access the information from the remote database（）

单项选择题 The database instance has the following parameter setting： OS_AUTHENT_PREFIX = OPS$ OS_ROLES = FALSE REMOTE_OS_AUTHENT = FALSE REMOTE_OS_ROLES = FALSE TIMED_OS_STATISTICS = 0 You have a local operating system user SKD.You create a database user OPS$SKD， and then assign external authentication. The user OPS$SKD has theCREATE SESSION privilege.  What would you achieve by the above process（）

单项选择题 WhydoesperformancedegradewhenmanyUPDATE，INSERT，orDELETEstatementsareissuedonatablethathasanassociatedBitmapindex（）