Oracle 12C--1z0-062（1）

Examine the parameters for your database instance:
You execute the following command:

SQL> ALTER TABLESPACE undotbs1 RETENTION NOGUARANTEE;
Which statement is true in this scenario?
A.
Undo data is written to flashback logs after 1200 seconds.
B.
Inactive undo data is retained for 1200 seconds even if subsequent transactions fail due to lack of space in the undo tablespace.
C.
You can perform a Flashback Database operation only within the duration of 1200 seconds.
D.
An attempt is made to keep inactive undo for 1200 seconds but transactions may overwrite the undo before that time has elapsed.

answer：D 指明retention为1200为不强制的。

A user establishes a connection to a database instance by using an Oracle Net connection. You want to ensure the following:
1. The user account must be locked after five unsuccessful login attempts.
2. Data read per session must be limited for the user.
3. The user cannot have more than three simultaneous sessions.
4. The user must have a maximum of 10 minutes session idle time before being logged off automatically.
How would you accomplish this?
A.
by granting a secure application role to the user
B.
by implementing Database Resource Manager
C.
by using Oracle Label Security options
D.
by assigning a profile to the user

answer：D profile是用来对用户所能使用的数据库资源进行限制的

As a user of the ORCL database, you establish a database link to the remote HQ database such that all users in the ORCL database may access tables only from the SCOTT schema in the HQ
database. SCOTT’s password is TIGER. The service mane “HQ” is used to connect to the remote HQ database.Which command would you execute to create the database link?
A.
CREATE DATABASE LINK HQ USING ‘HQ‘;
B.
CREATE DATABASE LINK HQ CONNECT TO CURRENT_USER USING ‘HQ’;
C.
CREATE PUBLIC DATABASE LINK HQ CONNECT TO scott IDENTIFIED BY tiger USING ‘HQ‘;
D.
CREATE DATABASE LINK HQ CONNECT TO scott IDENTIFIED BY tiger USING ‘HQ‘;

answer：考察dblink的写法，待测试