Oracle Oracle Certifications 1Z0-908 Questions & Answers

• Question 121:

  You have configured GTID-based asynchronous replication with one master and one slave.

  A user accidentally updated some data on the slave.

  To fix this, you stopped replication and successfully reverted the accidental changes.

  Examine the current GTID information:

  

  You must fix GTID sets on the slave to avoid replicating unwanted transactions in case of failover. Which set of actions would allow the slave to continue replicating without erroneous transactions?

  A. RESET MASTER; SET GLOBAL gtid_purged=aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:1-10167;

  B. SET GLOBAL gtid_purged=aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:1- 2312,bbbbbbbb- bbbb-bbbb-bbbb-bbbbbbbbbbbb:1-9; SET GLOBAL gtid_executed=aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:1-10167;

  C. RESET SLAVE; SET GLOBAL gtid_purged=aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:1-3820; SET GLOBAL gtid_executed=aaaaaaaa-aaaa-aaaa-aaaa--aaaaaaaaaaaa:1-10300;

  D. RESET MASTER; SET GLOBAL gtid_purged-aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:1-2312; SET GLOBAL gtid_executed=aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:1-10167;

  E. RESET SLAVE; SET GLOBAL gtid_purged=aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:1-10167;

  Correct Answer: D

• Question 122:

  A valid raw backup of the shop.customers MyISAM table was taken.

  You must restore the table. You begin with these steps:

  1.Confirm that secure_file_priv='/var/tmp'

  2.mysql> DROP TABLE shop.customers;

  3.shell> cp /backup/customers.MY* /var/lib/mysql/shop/

  Which two actions are required to complete the restore? (Choose two.)

  A. shell> cp /backup/customers.sdi /var/tmp

  B. shell> cp /backup/customers.sdi /var/lib/mysql/shop/

  C. mysql> SOURCE `/var/tmp/customers.sdi'

  D. mysql> IMPORT TABLE FROM /var/tmp/customers.sdi

  E. shell> cp /backup/customers.frm /var/lib/mysql/shop/

  F. mysql> IMPORT TABLE FROM /var/lib/mysql/shop/customers.sdi

  G. mysql> ALTER TABLE shop.customers IMPORT TABLESPACE

  H. mysql> ALTER TABLE shop.customers DISCARD TABLESPACE

  Correct Answer: DG

• Question 123:

  An existing asynchronous replication setup is running MySQL 8.

  Which two steps are a part of implementing GTID replication? (Choose two.)

  A. Enable GTID by executing this on the master and the slave: SET GLOBAL GTID_ENABLED=on;

  B. Execute this on the slave to enable GTID: START SLAVE IO_THREAD WITH GTID;

  C. Restart MySQL (master and slave) with these options enabled: --gtid_mode=ON --log-bin --log-slave-updates --enforce-gtid-consistency

  D. Execute this on the slave to enable GTID: RESET SLAVE; START SLAVE GTID_NEXT=AUTOMATIC;

  E. On the slave, alter the MySQL master connection setting with: ALTER channel CHANGE MASTER TO MASTER_AUTO_POSITION = 1;

  F. On the slave, alter the MySQL master connection setting with: CHANGE MASTER TO MASTER_AUTO_POSITION = 1;

  Correct Answer: CF

  Reference: https://dev.mysql.com/doc/refman/8.0/en/replication-gtids-howto.html

• Question 124:

  You have an installation of MySQL 8 on Oracle Linux.

  Consider the outputs: Which statement is true about disk temporary tables for this installation?

  

  A. Only internal temporary tables from the optimizer will be created in tmpdir.

  B. Temporary tables will use the InnoDB temporary tablespace located in datadir.

  C. Temporary tables are created in tmpdir only if configured to use MyISAM.

  D. Temporary tables are created in tmpdir only after they reach tmp_tabie_size.

  E. Temporary tables will use the InnoDB temporary tablespace located in /tmp.

  Correct Answer: A

• Question 125:

  Examine this partial output for InnoDB Cluster status:

  

  Which statement explains the state of the instance deployed on host2?

  A. It can be recovered from a donor instance on host3 by cloning using the command cluster.rejoinInstance ('@host3:3377')

  B. It can rejoin the cluster by using the command cluster.addInstance('@host3:3377')

  C. It has been removed from the cluster by using the command STOP GROUP_REPLICATION;

  D. It can rejoin the cluster by using the command dba.rebootClusterFromCompleteOutage()

  E. It has been expelled from the cluster because of a transaction error.

  Correct Answer: D

• Question 126:

  You have just installed MySQL on Oracle Linux and adjusted your /etc/my.cnf parameters to suit your installation. Examine the output:

  

  What statement is true about the start attempt?

  A. MySQL server was not started due to a problem while executing process 2732.

  B. MySQL server continued to start up even though another process existed.

  C. systemd found the mysqld service disabled and failed to start it.

  D. systemd waited for 30 seconds before timing out and start up failed.

  E. systemd attempted to start mysqld, found another systemd mysqld process running, and shut it down.

  Correct Answer: E

• Question 127:

  Examine this statement and output:

  

  You must try to reduce query execution time.

  Which two queries should you focus on? (Choose two.)

  A. QN = 3

  B. QN = 5

  C. QN = 1

  D. QN = 4

  E. QN = 2

  Correct Answer: CE

• Question 128:

  Which three are requirements for a secure MySQL Server environment? (Choose three.)

  A. Restrict the number of OS users that have access at the OS level.

  B. Ensure appropriate file system privileges for OS users and groups.

  C. Minimize the number of non-MySQL Server-related processes running on the server host.

  D. Encrypt the file system to avoid needing exact file-system permissions.

  E. Keep the entire software stack on one OS host.

  F. Run MySQL server as the root user to prevent incorrect sudo settings.

  Correct Answer: BDE

• Question 129:

  Examine this query:

  

  What information does this query provide?

  A. total memory used across all connections associated with the user on connection number 10

  B. total memory used by the first 10 connections

  C. total memory used by thread number 10

  D. total memory used across all connections associated with the user on thread number 10

  E. total memory used by connection number 10

  F. total memory used by the first 10 threads

  Correct Answer: E

• Question 130:

  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 cluster is running and there is at least one ONLINE instance.

  C. The instance deployed on host3 must be synchronized from a donor deployed on host1 by using the command cluster.addInstance(`host1:3377').

  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 active session instance is invalid and must be re-created by using the command shell.connect (`host3:3377').

  Correct Answer: C