多项选择题
A. The database must have multiplexed redo logs for the flashback to succeed.
B. The database must be MOUNTED for the flashback to succeed.
C. The database must use block change tracking for the flashback to succeed.
D. The database must be opened in restricted mode for the flashback to succeed.
E. The database must be opened with the RESETLOGS option after the flashback is complete.
F. The database must be opened in read-only mode to check if the database has been flashed back to the correct SCN.
多项选择题 Which three statements are true about SQL plan directives?（）
单项选择题 Your multitenant container database (CDB) contains pluggable databases (PDBs), you are connected to the HR_PDB. You execute the following command: SQL > CREATE UNDO TABLESPACE undotb01 DATAFILE ‘u01/oracle/rddb1/undotbs01.dbf’ SIZE 60M AUTOEXTEND ON; What is the result?（）
单项选择题 Your database has the SRV1 service configured for an application that runs on middle-tier application server. The application has multiple modules. You enable tracing at the service level by executing the following command: SQL > exec DBMS_MONITOR.SERV_MOD_ACT_TRACE_ENABLE (‘SRV1’); The possible outcome and actions to aggregate the trace files are as follows: 1. The command fails because a module name is not specified. 2. A trace file is created for each session that is running the SRV1 service. 3. An aggregated trace file is created for all the sessions that are running the SRV1 service. 4. The trace files may be aggregated by using the trcess utility. 5. The trace files be aggregated by using the tkprof utility. Identify the correct outcome and the step to aggregate by using tkprof utility?（）