053 第500题

500.You opened the encryption wallet and then issued the following command:
SQL>CREATE TABLESPACE securespace
DATAFILE '/home/user/oradata/secure01.dbf'
SIZE 150M
ENCRYPTION USING '3DES168'
DEFAULT STORAGE(ENCRYPT);
Then you closed the wallet. Later, you issued the following command to create the EMPLOYEES table in
the SECURESPACE tablespace and you use the NO SALT option for the EMPID column.
What is the outcome?
A. It creates the table and encrypts the data in it.
B. It generates an error because the wallet is closed.
C. It creates the table but does not encrypt the data in it.
D. It generates an error because the NO SALT option cannot be used with the ENCRYPT option.
Answer: B

Use this clause to specify the encryption properties of the tablespace. This clause does not actually encrypt the tablespace. You must also specify theENCRYPT keyword as part of the DEFAULT storage_clause in this statement in order for the tablespace to be encrypted. In addition, you must already have used ALTER SYSTEM SET ENCRYPTION WALLET OPEN IDENTIFIED BY ... to load the TDE master key into database memory for the duration of the instance, or establish a connection to the HSM to send the encrypted table and tablespace keys to the HSM and receive them back decrypted.

SALT | NO SALT Specify SALT to instruct the database to append a random string, called "salt," to the clear text of the column before encrypting it. This is the default.

Specify NO SALT to prevent the database from appending salt to the clear text of the column before encrypting it.

The following considerations apply when specifying SALT or NO SALT for encrypted columns:

• If you want to use the column as an index key, then you must specify NO SALT. Refer to Oracle Database Advanced Security Administrator's Guide for a description of "salt" in this context.

• If you specify table compression for the table, then the database does not compress the data in encrypted columns with SALT.

You cannot specify SALT or NO SALT for LOB encryption.

实验

SQL> CREATE TABLESPACE securespace
  2  datafile 'E:\oradata\test\secures01.dbf'
  3  SIZE 150M
  4  ENCRYPTION USING '3DES168'
  5  DEFAULT STORAGE(ENCRYPT);
CREATE TABLESPACE securespace
*
第 1 行出现错误:
ORA-28365: Wallet 未打开