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?
- 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 definition language (DDL), and queries performed by the session.