Your database is running in archivelog mode. Examine the parameters for your database
instance:
LOG_ARCHIVE_DEST_l =’LOCATION=/disk1/arch MANDATORY’
LOG_ARCHIVE_DEST_2 =’LOCATION=/disk2/arch’
LOG_ARCHIVE_DEST_3 =’LOCATIO=/disk3/arch’
LOG_ARCHIVE_DEST _4 =’LOCATIONs/disk4/arch’
LOG_ARCHIVE _MIN_SUCCEED_DEST = 2
While the database is open, you notice that the destination set by the log_archive_dest_1
parameter is not available. All redo log groups have been used.
What happens at the next log switch?
A.
The database instance hangs and the redo log files are not overwritten.
B.
The archived redo log files are written to the fast recovery area until the mandatory
destination is made available.
C.
The database instance is shutdown immediately.
D.
The destination set by the log_archive_dest parameter is ignored and the archived redo
log files are created in the next two available locations to guarantee archive log success.
d
Thats WRONG
Right answer is A
Read
The failure of any mandatory destination, including a mandatory standby destination, makes the LOG_ARCHIVE_MIN_SUCCEED_DEST parameter irrelevant.
MANDATORY and OPTIONAL
You can specify a policy for reusing online redo log files using the OPTIONAL or MANDATORY attributes. If a destination is optional, archiving to that destination may fail, yet the online redo log file is available for reuse and may be overwritten eventually. If the archival operation of a mandatory destination fails, online redo log files cannot be overwritten.
If neither the MANDATORY nor the OPTIONAL attribute is specified, the default is OPTIONAL. At least one destination must succeed even if all destinations are designated to be optional.
The LOG_ARCHIVE_MIN_SUCCEED_DEST=n parameter (where n is an integer from 1 to 10) specifies the number of destinations that must archive successfully before the log writer process can overwrite the online redo log files. All mandatory destinations and non-standby optional destinations contribute to satisfying the LOG_ARCHIVE_MIN_SUCCEED_DEST=ncount. For example, you can set the parameter as follows:
# Database must archive to at least two locations before
# overwriting the online redo log files.
LOG_ARCHIVE_MIN_SUCCEED_DEST = 2
When determining how to set your parameters, note that:
This attribute does not affect the data protection mode for the destination.
You must have at least one local destination, which you can declare OPTIONAL or MANDATORY.
At least one local destination is operationally treated as mandatory, because the minimum value for the LOG_ARCHIVE_MIN_SUCCEED_DEST parameter is 1.
The failure of any mandatory destination, including a mandatory standby destination, makes the LOG_ARCHIVE_MIN_SUCCEED_DEST parameter irrelevant.
The LOG_ARCHIVE_MIN_SUCCEED_DEST parameter value cannot be greater than the number of destinations, nor greater than the number of mandatory destinations plus the number of optional local destinations.
If you defer a mandatory destination, and the online redo log file is overwritten without transferring the redo data to the standby site, then you must transfer the redo log file to the standby site manually.
The BINDING column of the V$ARCHIVE_DEST fixed view specifies how failure affects the archival operation.
MANDATORY
Specifies that the transmission of redo data to the destination must succeed before the local online redo log file can be made available for reuse.
OPTIONAL
Specifies that successful transmission of redo data to the destination is not required before the online redo log file can be made available for reuse. If the value set for the LOG_ARCHIVE_MIN_SUCCEED_DEST parameter (that defines the minimum number of destinations that must receive redo data successfully before the log writer process on the primary database can reuse the online redo log file) is met, the online redo log file is marked for reuse.
Examples
The following example shows the MANDATORY attribute:
LOG_ARCHIVE_DEST_1=’LOCATION=/arch/dest MANDATORY’
LOG_ARCHIVE_DEST_STATE_1=ENABLE
LOG_ARCHIVE_DEST_3=’SERVICE=denver MANDATORY’
LOG_ARCHIVE_DEST_STATE_3=ENABLE
Thanks Vonpire!
And here is the doc:
https://docs.oracle.com/cd/B28359_01/server.111/b28294/log_arch_dest_param.htm#i77784
So, A. Oracle doc IS NOT wrong.
Vonpire,
I think is D, look the test.
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.
So oracle documentation is wrong?
Youre right. I made the testcase and D is the answer. Oracle documentation I provided appears to be wrong!
OK RIGHT ANSWER IS A!
Made more logfile switch until all redos groups are full. first log switch succeds, second also succeds then next will hang database.
Oracle documentation IS NOT WRONG!
Question clearly states All redo log groups have been used.
Do the test and youll see I was right as well as oracle doc.
A is the correct answer!
Hi Vonpire. Do you have any suggestions for better preparing for 1Z0-067?
Regards
Max
You right Vonpire, this answer is A, very well.
Thank you!!
A
A
are you doing the test in 12c database ?
I have performed test on Oracle 12c database and the correct answer for me is D.
Oracle documentation says: ‘The failure of any mandatory destination makes the LOG_ARCHIVE_MIN_SUCCEED_DEST parameter irrelevant.’
D – I was test this example in 12c.
log_archive_dest_1 string location=/db/log_1 mandatory
log_archive_dest_2 string location=/db/log_2
log_archive_dest_3 string location=/db/log_3
log_archive_dest_4 string location=/db/log_4
log_archive_min_succeed_dest integer 2
alter system switch logfile;
/
/
/
have not errors
$cd /db
$mv log_1 log_01
alter system switch logfile;
/
/
/
have not errors
A
https://docs.oracle.com/cd/B28359_01/server.111/b28294/log_arch_dest_param.htm#i77784
if the archival operation of a mandatory destination fails, online redo log files cannot be overwritten.
D
D !!
The failure of any mandatory destination, including a mandatory standby destination, makes the LOG_ARCHIVE_MIN_SUCCEED_DEST parameter irrelevant.
A