Click the Exhibit button. In the exhibit, the Compression > Basic > Endpoints page shows an icon of a red "X" under the tunnel status "IN" column. The error message displays, "No Request Received". What does this indicate?（）

A、 There are no devices at the remote site.

B、 The remote side does not have QoS enabled.

C、 The remote side is not configured for compression to this endpoint.

D、 The remote side is not configured for decompression to this endpoint.

You need to ensure that the database users should be able to use the various flashback query features in order to go back in time by four hours. What would you do to achieve this?（）

set SQL_TRACE=True 

set UNDO_RETENTION=14400 

set FAST_START_MTTR_TARGET=240 

set LOG_CHECKPOINT_INTERVAL=240 

set DB_FLASHBACK_RETENTION_TARGET=14400 

set the RETENTION GUARANTEE clause for the undo tablespace

以昆虫为媒介而传播的疾病是（）

A、麻疹

B、戊型肝炎

C、艾滋病

D、流行性出血热

E、结核病

What are two requirements when using Packet Flow Acceleration? （）(Choose two.)

Traffic needs be compressed.

Quality of service must be enabled.

A service tunnel must exist in at least one direction.

PFA must be enabled on the client-side WX device.

A UDT is a data type which:（）

A、must contain unique values.

B、cannot be CAST to other data types.

C、is created using the CREATE DISTINCT command.

D、contains a value that was automatically calculated from values in other columns.

Which object may be used during query optimization to improve the performance for a subset of SELECT queries?（）

A、MQT

B、Trigger

C、Read Only Cursor

D、Stored Procedure