Oracle 1Z0-908 問題集

質問 1：
An attempt to recover an InnoDB Cluster fails.
Examine this set of messages and responses:
host3:3377 ssl JS > dba.rebootClusterFromCompleteOutage() Reconfiguring the default cluster from complete outage...
The instance 'host1:3377'' was part of the cluster configuration. Would you like to rejoin it to the cluster?
[y/N]: y
The instance 'host2:3377' was part of the cluster configuration. Would you like to rejoin it to the cluster?
[y/N]: y
Dba.rebootClusterFromCompleteOutage: The active session instance isn't the most updated in comparison with the ONLINE instances of the Cluster's metadata. Please use the most up to date instance: 'host1:3377'.
(RuntimeError)
Which statement is true?
A. The instance deployed on host3 must be rebuilt with a backup from the primary instance.
B. The active session instance is invalid and must be re-created by using the command shell.connect ('host3:3377').
C. The cluster is running and there is at least one ONLINE instance.
D. It is possible to determine the most up-to-date instance by comparing different global transaction identifier (GTID) sets with GTID_SUBSET(set1,set2).
E. The instance deployed on host3 must be synchronized from a donor deployed on host1 by using the command cluster.addInstance('host1:3377').
正解：E

質問 2：
Which three are characteristics of a newly created role? (Choose three.)
A. It can be protected with a password.
B. It is created as a locked account.
C. It is stored in the mysql.role table.
D. It can be granted to user accounts.
E. It can be dropped using the DROP ROLE statement.
F. It can be renamed using the RENAME ROLE statement.
正解：A,D,E
解説: (Topexam メンバーにのみ表示されます)

質問 3：
Your MySQL environment has asynchronous position based-replication with one master and one slave.
The slave instance had a disk I/O problem, so it was stopped.
You determined that the slave relay log files were corrupted and unusable, but no other files are damaged.
You restart MySQL Server.
How can replication be restored?
A. The slave relay logs should be deleted; execute CHANGE MASTER to adjust the replication relay log file name, then issue start SLAVE;
B. The relay logs from the master should be used to replace the corrupted relay logs.
C. The slave needs to be restored from backup.
D. The slave relay logs should be deleted; then execute START SLAVE;
正解：B

質問 4：
All MySQL Server instances belonging to InnoDB Cluster have SSL configured and enabled.
You must configure InnoDB Cluster to use SSL for group communication.
Which two statements are true? (Choose two.)
A. SSL group communication requires the use of an additional set of parameters group_replication_recovery_*.
B. An existing InnoDB Cluster must be dissolved and created from scratch to enable SSL for group communication.
C. If only some InnoDB Cluster members are enabled for SSL group communication, and
--ssl-mode=PREFERRED, communication will fall back to unencrypted connection.
D. Configuring SSL group communication also configures SSL distributed recovery.
E. SSL group communication must be enabled at cluster creation time by specifying createCluster ({memberSslMode: 'REQUIRED'}).
F. SSL group communication can be enabled for an existing cluster, one instance at time, by setting group_replication_ssl_mode.
正解：A,E

質問 5：
Which statement is true about InnoDB persistent index statistics?
A. Increasing innodb_stats_persistent_sample_pages determines higher pages scanning speed, at the cost of increased memory usage.
B. Index statistics are calculated from pages buffered in the buffer pool for tables with InnoDB storage engine.
C. Execution plans based on transient index statistics improve precision when innodb_stats_persistent_sample_pages is increased.
D. Setting innodb_stats_auto_recalc=ON causes statistics to be updated automatically when a new index is created.
E. Updating index statistics is an I/O expensive operation.
正解：E