About Altering the Default Full Data Redaction Value You can alter the default displayed values for full Data Redaction polices. By default, 0 is the redacted value when Oracle Database performs full redaction (DBMS_REDACT.FULL) on a column of the NUMBER data type. If you want to change it to another value (for example, 7), then you can run the DBMS_REDACT.UPDATE_FULL_REDACTION_VALUES procedure to modify this value. The modification applies to all of the Data Redaction policies in the current database instance. After you modify a value, you must restart the database for it to take effect.
Note:
*The DBMS_REDACT package provides an interface to Oracle Data Redaction, which enables you to mask (redact) data that is returned from queries issued by low-privileged users or an application.
*UPDATE_FULL_REDACTION_VALUES Procedure
*After you create the Data Redaction policy, it is automatically enabled and ready to redact data.
*Oracle Data Redaction enables you to mask (redact) data that is returned from queries issued by low-privileged users or applications. You can redact column data by using one of the following methods:
This procedure modifies the default displayed values for a Data Redaction policy for full redaction.
/ Full redaction. / Partial redaction. / Regular expressions. / Random redaction. / No redaction.
Reference: Oracle Database Advanced Security Guide 12c, About Altering the Default Full Data Redaction Value

http://docs.oracle.com/cd/E16655_01/server.121/e17209/statements_8003.htm#SQLRF54751 If you omit this clause and the current container is a PDB, then CONTAINER = CURRENT is the default. If you omit this clause and the current container is the root, then CONTAINER = ALL is the default.
create table only in current container

During SQL execution, if a cardinality misestimate occurs, then the database creates SQL plan directives. During SQL compilation, the optimizer examines the query corresponding to the directive to determine whether missing extensions or histograms exist (D). The optimizer records any missing extensions. Subsequent DBMS_STATS calls collect statistics for the extensions.
The optimizer uses dynamic sampling whenever it does not have sufficient statistics corresponding to the directive. (B, not C)
E: Currently, the optimizer monitors only column groups. The optimizer does not create an extension on expressions.
Incorrect:
Not A: SQL plan directives are not tied to a specific SQL statement or SQL ID.
Note:
* A SQL plan directive is additional information and instructions that the optimizer can use to generate a more optimal plan. For example, a SQL plan directive can instruct the optimizer to record a missing extension.

If you run multiple AUDIT statements on the same unified audit policy but specify different EXCEPT users, then Oracle Database uses the last exception user list, not any of the users from the preceding lists. This means the effect of the earlier AUDIT POLICY ... EXCEPT statements are overridden by the latest AUDIT POLICY ... EXCEPT statement.
Note:
*The ORA_DATABASE_PARAMETER policy audits commonly used Oracle Database parameter settings. By default, this policy is not enabled.
*You can use the keyword ALL to audit all actions.The following example shows how to audit all actions on the HR.EMPLOYEES table, except actions by user pmulligan.
Example Auditing All Actions on a Table
CREATE AUDIT POLICY all_actions_on_hr_emp_pol
ACTIONS ALL ON HR.EMPLOYEES;
AUDIT POLICY all_actions_on_hr_emp_pol EXCEPT pmulligan;