You performed an incomplete recovery and opened the database with the RESETLOGS
option. The LOG_ARCHIVE_FORMAT parameter is set to ‘ora_%t_%s_%r.log’. Which
statement regarding the archived redo log files, created in an earlier incarnation of the
database, is true?
A.
The archived redo log files will be overwritten.
B.
The archived redo log files are deleted automatically.
C.
The archived redo log files should be moved to some other location.
D.
The archived redo log files are still maintained because the file names are unique.
D is correct:
https://docs.oracle.com/cd/B19306_01/server.102/b14237/initparams103.htm#REFRN10089
OG_ARCHIVE_FORMAT is applicable only if you are using the redo log in ARCHIVELOG mode. Use a text string and variables to specify the default filename format when archiving redo log files. The string generated from this format is appended to the string specified in the LOG_ARCHIVE_DEST parameter.
The following variables can be used in the format:
%s log sequence number
%S log sequence number, zero filled
%tthread number
%Tthread number, zero filled
%a activation ID
%d database ID
%r resetlogs ID that ensures unique names are constructed for the archived log files across multiple incarnations of the database
Because of ‘ora_%t_%s_%r.log’ including %r, the unique names are maintained.