You want to flash back a test database by five hours.You issue this command:SQL > FLASHBACK DATABASE TO TIMESTAMP (SYSDATE - 5/24);Which two statements are true about this flashback scenario?（）

多项选择题Which three statements are true about SQL plan directives?（）

A. They are tied to a specific statement or SQL id.
B. They instruct the maintenance job to collect missing statistics or perform dynamic sampling to generate a more optimal plan.
C. They are used to gather only missing statistics.
D. They are created for a query expression where statistics are missing or the cardinality estimates by the optimizer are incorrect.
E. They instruct the optimizer to create only column group statistics.
F. Improve plan accuracy by persisting both compilation and execution statistics in the SYSAUX tablespace.

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?（）

A. It executes successfully and creates an UNDO tablespace in hr_pdb.
B. It falls and reports an error because there can be only one undo tablespace in a cdb.
C. It fails and reports an error because the CONTAINER=ALL clause is not specified in the command.
D. It fails and reports an error because the CONTAINER=CURRENT clause is not specified in the command.
E. It executes successfully but neither tablespace nor the data file is created.

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?（）

A. 1
B. 2 and 4
C. 2 and 5
D. 3 and 4
E. 3 and 5

单项选择题You are about to plug a multi-terabyte non-CDB into an existing multitenant container database (CDB) as a pluggable database (PDB). The characteristics of the non-CDB are as follows: -Version: Oracle Database 12c Releases 1 64-bit -Character set: WE8ISO8859P15 -National character set: AL16UTF16 -O S: Oracle Linux 6 64-bit The characteristics of the CDB are as follows: -Version: Oracle Database 12c Release 1 64-bit -Character set: AL32UTF8 -O S: Oracle Linux 6 64-bit Which technique should you use to minimize down time while plugging this non-CDB into the CDB?（）

A. Transportable database
B. Transportable tablespace
C. Data Pump full export / import
D. The DBMS_PDB package
E. RMAN

多项选择题Which three statements are true about the working of system privileges in a multitenant control database(CDB) that has pluggable databases (PDBs)?（）

A. System privileges apply only to the PDB in which they are used.
B. Local users cannot use local system privileges on the schema of a common user.
C. The granter of system privileges must possess the set container privilege.
D. Common users connected to a PDB can exercise privileges across other PDBs.
E. System privileges with the with grant option container all clause must be granted to a common user before the common user can grant privileges to other users.