Upgrade Oracle DBA 11g to Oracle Database 12c — Question 12

You create a table with the period for clause to enable the use of the Temporal Validity feature of Oracle Database 12c.
Examine the table definition:
create table employees
(empno number, salary number,
deptid number, name varchar2(100),
period for employee_time);
Which three statements are true concerning the use of the Valid Time Temporal feature for the EMPLOYEES table?

Answer options

• A. The valid time columns employee_time_start and employee_time_end are automatically created.
• B. The same statement may filter on both transaction time and valid temporal time by using the AS OF TIMESTAMP and PERIOD FOR clauses.
• C. The valid time columns are not populated by the Oracle Server automatically.
• D. The valid time columns are visible by default when the table is described.
• E. Setting the session valid time using DBMS_FLASHBACK_ARCHIVE.ENABLE_AT_VALID_TIME sets the visibility for data manipulation language (DML), data

Correct answer: A, B, E

Explanation

Option A is correct because the valid time columns are indeed created automatically when using the PERIOD FOR clause. Option B is also true as it allows filtering on both transaction and valid time using the respective clauses. Option E is correct regarding session valid time visibility. However, options C and D are incorrect; the valid time columns are not automatically populated, and they are not visible by default when the table is described.