The instance abnormally terminates because of a power outage. Which statement is true
about redo log files during instance recovery?
A.
Online and archived redo files are required to accomplish instance recovery
B.
All redo log entries after the last checkpoint are applied from redo log files to data files
C.
Inactive and current redo log files are required to accomplish recovery
D.
All redo log entries recorded in the current log file until the checkpoint position are
applied to data files
B
https://docs.oracle.com/cd/E11882_01/server.112/e40540/startup.htm#CNCPT1301
Overview of Instance Recovery
Instance recovery is the process of applying records in the online redo log to data files to reconstruct changes made after the most recent checkpoint. Instance recovery occurs automatically when an administrator attempts to open a database that was previously shut down inconsistently.
…
When a transaction is committed, log writer (LGWR) writes both the remaining redo entries in memory and the transaction SCN to the online redo log. However, the database writer (DBW) process writes modified data blocks to the data files whenever it is most efficient. For this reason, uncommitted changes may temporarily exist in the data files while committed changes do not yet exist in the data files.
…
Instance recovery uses only online redo log files and current online data files to synchronize the data files and ensure that they are consistent.