The EMP table has some discrepancy in data entry with a particular employee ID. You execute the query as
shown in the Exhibit to retrieve all versions of the row that exist between two SCNs.View the Exhibit.
Which two statements about the results of the query shown in the Exhibit are correct? (Choose two.)
Exhibit:
A.
The LAST_SCN value in the first row is NULL, which means that the versions of the row still exist at SCN
6636300.
B.
The LAST_SCN value in the second row in NULL, which means that the version of the row still exists at
SCN 6636300.
C.
The LAST_SCN value in the third row is 6636280, which means that the version of row exists above SCN
6636280.
D.
The LAST_SCN value in the second row is NULL, which means that the version of the row no longer exists
because it was deleted.
Explanation:
Using Oracle Flashback Transaction Query with Oracle Flashback Version Query (link)
The query uses Oracle Flashback Version Query pseudocolumns:
SELECT versions_xid XID, versions_startscn START_SCN,
versions_endscn END_SCN, versions_operation OPERATION,
empname, salary
FROM emp
VERSIONS BETWEEN SCN MINVALUE AND MAXVALUE
WHERE empno = 111;
Results are similar to:3 rows selected.
The results table rows are in descending chronological order.
