You have configured flash recovery area in your database and you set the following Initialization
parameters for your database instance:
LOG_ARCHIVE_DEST 1 = LOCATION=/disk1/arch MANDATORY’
LOG _ARCHIEVE_DEST 2 = LOCATION=/disk2/arch’
LOG_ARCHIVK_DEST_3 = LOCATION=/diSk3/arch
LOG_ARCH1VK_DEST_4 = ‘ LOCATION=/disk4/arch’
LOG_ARCHIVE_MIN-SUCCEED_DEST = 2
While the database instance is functional, you realized that the destination set by the
LOG_ARCHIVE_DEST_I parameter Is not available for the archived redo log file to be created in.
All redo log groups have been used. What happens in an event of log switch?
A.
The online redo log file Is not allowed to be overwritten.
B.
The archived redo log files are written to the flash recovery area until the MANDATORY
destination is made available.
C.
The database instance will crash because the archived redo log file cannot be created in a
destination set as MANDATORY.
D.
The destination set by the LOG_ARCHIVE_DEST_1 parameter is ignored and the archived
redo log files are created in the next two available locations to guarantee archive log success.
Wrong answer.
For mandatory archive log destinations, if the archive log cannot be written to the location successfully, the online redo log file will not be overwritten.
“LOG_ARCHIVE_MIN_SUCCEED_DEST defines the minimum number of destinations that must succeed in order for the online logfile to be available for reuse.”
http://docs.oracle.com/cd/B28359_01/server.111/b28320/initparams120.htm#REFRN10091
I think D is correct, LOG_ARCHIVE_MIN-SUCCEED_DEST = 2 is a clue
LOG_ARCHIVE_MIN_SUCCEED_DEST defines the minimum number of destinations that must succeed in order for the online logfile to be available for reuse.
If the value of this parameter is less than the number of enabled, valid MANDATORY destinations, this parameter is ignored in favor of the MANDATORY destination count. If the value is more than the number of enabled, valid MANDATORY destinations, some of the enabled, valid OPTIONAL non-standby destinations are treated as MANDATORY.
Which prooves that A is the right answer! “If the value is more than the number of enabled, valid MANDATORY destinations, some of the enabled, valid OPTIONAL non-standby destinations are treated as MANDATORY.” this means that the mandatory + another dest (2,3,4) must also succeed! Archiving only in mandatory location is not enouh, but failing of the mandatory one is CRITICAL!
The Sybex OCP said:
“In addition, if any archive log destination is designated as MANDATORY, a failure
of this destination prevents the online log files from being overwritten until the
failure is resolved. In this case, parameter LOG_ARCHIVE_MIN_SUCCEED_DEST is
also ignored”
i think that A is a answer
agree
The answer is A
Here’s the test case
SQL > CREATE pfile=’/tmp/initorcl.ora’ from spfile;
SQL > shutdown immediate
$cat /tmp/initorcl.ora
** add the below lines to initorcl.ora **
log_archive_min_succeed_dest=2
log_archive_dest_1=’LOCATION=/home/oracle/u01 MANDATORY’
log_archive_dest_2=’LOCATION=/home/oracle/u02′
SQL > STARTUP pfile=’/tmp/initorcl.ora’;
SQL> show parameter archive
** Extract of the result **
NAME TYPE VALUE
log_archive_dest_1 string LOCATION=/home/oracle/u01 MANDATORY
log_archive_dest_2 string LOCATION=/home/oracle/u02
log_archive_min_succeed_dest integer 2
SQL> ALTER SYSTEM SWITCH LOGFILE;
SQL> !ls -l /home/oracle/u01
/* To verify if its creating logs */
SQL>! rm -rf /home/oracle/u01
SQL > ALTER SYSTEM SWITCH LOGFILE;
Conclusion
DEST_1 is ignored and archivelogs are created in the next 2 available locations.
oops.. typo.. the answer is D!