On your Oracle 12c database, you Issue the following commands to create indexes
SQL > CREATE INDEX oe.ord_customer_ix1 ON oe.orders (customers_id, sales_rep_id) INVISIBLE;
SQL> CREATE BITMAP INDEX oe.ord_customer_ix2 ON oe.orders (customers_id, sales_rep_id);
Which two statement are correct?（）

单项选择题A database is stored in an Automatic Storage Management (ASM) disk group, disk group, DGROUP1 with SQL: There is enough free space in the disk group for mirroring to be done. What happens if the CONTROLLER1 failure group becomes unavailable due to error of for maintenance?（）

A. Transactions and queries accessing database objects contained in any tablespace stored in DGROUP1 will fall.
B. Mirroring of allocation units will be done to ASM disks in the CONTROLLER2 failure group until the CONTROLLER1 for failure group is brought back online.
C. The data in the CONTROLLER1 failure group is copied to the controller2 failure group and rebalancing is initiated.
D. ASM does not mirror any data until the controller failure group is brought back online, and newly allocated primary allocation units (AU) are stored in the controller2 failure group, without mirroring.
E. Transactions accessing database objects contained in any tablespace stored in DGROUP1 will fail but queries will succeed.

多项选择题Which two are prerequisites for performing a flashback transaction?（）

A. Flashback Database must be enabled.
B. Undo retention guarantee for the database must be configured.
C. EXECUTE privilege on the DBMS_FLASHBACK package must be granted to the user flashing back transaction.
D. Supplemental logging must be enabled.
E. Recycle bin must be enabled for the database.
F. Block change tracking must be enabled tor the database.

单项选择题You are connected to a pluggable database (PDB) as a common user with DBA privileges. The STATISTICS_LEVEL parameter is PDB_MODIFIABLE. You execute the following: SQL > ALTER SYSTEM SET STATISTICS_LEVEL = ALL SID = ‘*’ SCOPE = SPFILE; Which is true about the result of this command?（）

A. The STATISTICS_LEVEL parameter is set to all whenever this PDB is re-opened.
B. The STATISTICS_LEVEL parameter is set to ALL whenever any PDB is reopened.
C. The STATISTICS_LEVEL parameter is set to all whenever the multitenant container database (CDB) is restarted.
D. Nothing happens; because there is no SPFILE for each PDB, the statement is ignored.

多项选择题In which two scenarios do you use SQL* Loader to load data?（）

A. Transform the data while it is being loaded into the database.
B. Use transparent parallel processing without having to split the external data first.
C. Load data into multiple tables during the same load statement.
D. Generate unique sequential key values in specified columns.

单项选择题Examine the following command; ALTER SYSTEM SET enable_ddl_logging = TRUE; Which statement is true?（）

A. Only the data definition language (DDL) commands that resulted in errors are logged in the alert log file.
B. All DDL commands are logged in the alert log file.
C. All DDL commands are logged in a different log file that contains DDL statements and their execution dates.
D. Only DDL commands that resulted in the creation of new segments are logged.
E. All DDL commands are logged in XML format in the alert directory under the Automatic Diagnostic Repository (ADR) home.