nerdexam
Oracle

1Z0-060 · Question #120

You want to flash back a test database by five hours. You issue this command: SQL > FLASHBACK DATABASE TO TIMESTAMP (SYSDATE - 5/24); Which two statements are true about this flashback scenario?

The correct answer is B. The database must be MOUNTED for the flashback to succeed. E. The database must be opened with the RESETLOGSoption after the flashback is complete. FLASHBACK DATABASE requires the database to be in MOUNT state during the operation and must be opened with RESETLOGS afterward to establish a new redo log incarnation.

New Features for Availability

Question

You want to flash back a test database by five hours. You issue this command:

SQL > FLASHBACK DATABASE TO TIMESTAMP (SYSDATE - 5/24); Which two statements are true about this flashback scenario?

Options

  • AThe database must have multiplexed redo logs for the flashback to succeed.
  • BThe database must be MOUNTED for the flashback to succeed.
  • CThe database must use block change tracking for the flashback to succeed.
  • DThe database must be opened in restricted mode for the flashback to succeed.
  • EThe database must be opened with the RESETLOGSoption after the flashback is complete.
  • FThe database must be opened in read-only mode to check if the database has been flashed back to

How the community answered

(23 responses)
  • B
    78% (18)
  • C
    4% (1)
  • D
    13% (3)
  • F
    4% (1)

Why each option

FLASHBACK DATABASE requires the database to be in MOUNT state during the operation and must be opened with RESETLOGS afterward to establish a new redo log incarnation.

AThe database must have multiplexed redo logs for the flashback to succeed.

Multiplexed redo logs are a high-availability best practice but are not a prerequisite for FLASHBACK DATABASE; the actual requirement is that flashback logging was previously enabled via the FLASHBACK DATABASE mode and DB_FLASHBACK_RETENTION_TARGET parameter.

BThe database must be MOUNTED for the flashback to succeed.Correct

The FLASHBACK DATABASE command can only be issued while the database is in MOUNT state because Oracle must apply flashback logs to roll back datafiles to the target timestamp without any active sessions or open datafiles interfering with the block-level undo process.

CThe database must use block change tracking for the flashback to succeed.

Block change tracking is a feature that accelerates incremental RMAN backups by recording changed block addresses; it plays no role in the FLASHBACK DATABASE process, which uses flashback logs stored in the fast recovery area.

DThe database must be opened in restricted mode for the flashback to succeed.

Restricted mode is used to limit access to an already-open database during maintenance; FLASHBACK DATABASE requires the database to be MOUNTED (not open in any mode, including restricted), so this choice describes an incompatible state.

EThe database must be opened with the RESETLOGSoption after the flashback is complete.Correct

After FLASHBACK DATABASE completes, the redo log sequence is no longer consistent with the restored SCN timeline, so Oracle requires the database to be opened with the RESETLOGS option to reset the log sequence number and create a new database incarnation.

FThe database must be opened in read-only mode to check if the database has been flashed back to

Opening the database in read-only mode after flashback is an optional verification step to confirm the correct point in time was reached before committing to RESETLOGS; it is not a mandatory requirement for the flashback operation itself to succeed.

Concept tested: FLASHBACK DATABASE prerequisites and post-operation RESETLOGS requirement

Source: https://docs.oracle.com/database/121/BRADV/flashback.htm

Topics

#flashback database#MOUNTED state#RESETLOGS#flashback prerequisites

Community Discussion

No community discussion yet for this question.

Sign up to join the discussion
Full 1Z0-060 Practice