Answers to Review Questions - OCP: Oracle Database 12c Administrator Certified Professional - page 675

new transactions, or that the user has exceeded the undo quota that has been set by the
database resource manager. FLASHBACK GUARANTEE is not a valid option, so option B is
incorrect. Flashback queries would not interfere with transactions entering the system,
so options C and D are incorrect.
8. D. Flashback Version Query does not change data at all, so option A is incorrect. B could
be correct, but only if one of the specified points in time was the current timestamp.
Therefore, B is not the best description. Option C is incorrect because Flashback Version
Query does not provide the SQL to undo the changes.
9. C. The VERSIONS_XID column contains the unique transaction identifier for the row.
None of the other choices are valid pseudocolumn names.
10. A, C. Lists of values are not valid, so both B and E are incorrect. Also, sequence values
are not valid, so D is also incorrect.
11. E. A Flashback Drop operation restores dropped objects from the Recycle Bin. It does
not use SCN or timestamp ranges, so options A, B, and D are incorrect. Also, Flashback
Drop operations don't create objects in the Recycle Bin (they move them out of the Recy-
cle Bin), so C is incorrect. The likely cause is that multiple versions of the table existed in
the Recycle Bin and the wrong one was restored.
12. C. The VERSIONS BETWEEN clause of the Flashback Version Query cannot query past
table modifications or DDL changes to a table.
13. D. Like the other Flashback options, Flashback Table must be able to find the necessary
undo records in order to recover. The use of SCNs is valid in Flashback Table; therefore
option A is incorrect. Row movement must be enabled in all cases, not just when a sig-
nificant number of changes have been made. Therefore option B is incorrect. One of the
main features of Flashback Table is that the tablespace can remain online, so option C
is incorrect.
14. A. The default action for the FLASHBACK TABLE command is to disable all triggers
regardless of their previous state. If the ENABLE TRIGGER clause is added to the
FLASHBACK TABLE command, then triggers that were previously enabled will be
reenabled after the operation completes.
15. B, C. FLASHBACK_TRANSACTION_QUERY is the correct view to query, and it can be done
using either timestamps or SCN ranges. DBA_TRANSACTION_QUERY is not a valid view;
therefore options A and D are incorrect.
16. B. Flashback Database relies on flashback logs in the fast recovery area. The Flashback
Data Archive and undo tablespace are not required. The RMAN command line is not
required to recover to a flashback point; the DBA can execute the FLASHBACK DATABASE
command from within SQL Plus.
17. C. The Flashback Database architecture consists of the recovery writer RVWR back-
ground process and Flashback Database logs. When the Flashback Database is enabled,