Oracle Oracle Database 1Z0-888 Questions & Answers

• Question 1:

  Given these table definitions and the explain plan: Which ALTER TABLE statement will improve the performance of the query?

  

  A. ALTER TABLE `CountryLanguage` ADD INDEX `idx_Lang` (`Language`);

  B. ALTER TABLE `Country` ADD INDEX `idx_Code` (`Code`);

  C. ALTER TABLE `CountryLanguage` ADD INDEX `idx_OffLang` (`IsOfficial`, `Language`);

  D. ALTER TABLE `Country` ADD INDEX `idx_NameCont` (`Name`, `CountryCode`);

  Correct Answer: B

• Question 2:

  You have a MySQL instance running in a single cpu (1vCPU) VM in a shared infrastructure environment.

  Your users are complaining that MySQL is sporadically slow and you have a suspicion that the VM infrastructure host is at fault due to resource contention.

  You review the output of your scripts that monitor the database VM operating system during an extended period of slowdown.

  What are the two most common indicators of the VM infrastructure host being at fault due to resource contention? (Choose two.)

  A. 10% CPU

  B. 90% RAM

  C. 9.1 five minute load average, 10% iowait

  D. 100% CPU use, 50% RAM

  E. 100% iowait

  F. 100% SWAP, 100% RAM

  Correct Answer: DF

• Question 3:

  Assuming that a user has correct privileges, which Linux console command will fail to shut down a MySQL server?

  A. mysqld -e 'shutdown'

  B. service mysqld stop

  C. mysqladmin shutdown

  D. mysql -e 'shutdown'

  Correct Answer: A

• Question 4:

  You want to create the first configuration file for a new installation of MySQL.

  1.

  You will start mysqld manually (not automate it to start when the host machine starts or execute as a service).

  2.

  You will stop mysqld using mysqladmin.

  3.

  You will interact with mysqld by using only the command-line client mysql.

  Which option identifies a maximal set of sections where you can put the "max_allowed_packet=16M" parameter without creating a problem?

  A. [mysql] and [mysqld] and [mysqladmin]

  B. [mysql] and [mysqladmin]

  C. [mysql]

  D. [mysqld]

  E. [mysqld] and [mysqladmin]

  F. [mysqladmin]

  G. [mysql] and [mysqld]

  Correct Answer: C

  Reference: https://dev.mysql.com/doc/refman/8.0/en/program-variables.html

• Question 5:

  You are installing MySQL Server 5.7 from a tarball package. You have already set up the correct PATH environment variable and configured your /etc/my.cnf file.

  Which command will correctly prepare a data directory?

  A. service mysqld prepare-init

  B. mysqld_safe --initialize ...

  C. mysql -u root -p < support-files/mysqldb.sql

  D. mysqld_safe --user=mysql

  E. mysqld --initialize ...

  Correct Answer: E

  Reference: https://dev.mysql.com/doc/refman/5.7/en/data-directory-initialization.html

• Question 6:

  You have a scheduled task on Linux that executes mysqldump against the localhost server periodically.

  When checking the logs of this event to ensure that things are working and that backups will restore, you

  notice an output that is concerning.

  The command the scheduled task is executing as follows:

  $ mysqldump -u backupuser -h 127.0.0.1 -pt100043va living --protocol=TCP

  > /backups/latest.sql

  Warning: Using a password on the command-line interface can be insecure.

  Which two methods are available to avoid the warning? (Choose two.)

  A. Use mysql_config_editor, which allows you to store encrypted login credentials in your home directory.

  B. Use the password validation plugin available to improve user name and password strength.

  C. Store your password in an option file eg: ~/.my.cnf and use --defaults-file so that it is read and used. [client] password=t100043va

  D. Connect through the --socket rather than the default --protocol=TCP for local connection. $ mysqldump -u backupuser -h 127.0.0.1 -pt100043va living -socket=/tmp/mysql.sock > /backups/latest.sql

  Correct Answer: AB

  Reference: https://dev.mysql.com/doc/mysql-security-excerpt/8.0/en/password-security-user.html https://dev.mysql.com/doc/refman/5.6/en/validate-password.html

• Question 7:

  What are three typical causes of MySQL becoming suddenly slow and unavailable? (Choose three.)

  A. A configuration change was made.

  B. The hardware includes a single point of failure.

  C. Monitoring has not enabled all Performance Schema instruments.

  D. The MySQL Query Cache is disabled.

  E. OPTIMIZE TABLE is not executed for the InnoDB tables.

  F. The application executes a new untested query.

  Correct Answer: CDE

• Question 8:

  You are using the mysqldumpslow utility to view the contents of the slow query log.

  You notice the letter N and the character string `S' in a number of locations in the output.

  What does the N indicate?

  A. the number of times the statement was executed

  B. an abbreviation for NULL in a statement

  C. the name of the user issuing the statement

  D. an abstracted substitution for numbers indicated in WHERE clauses

  Correct Answer: A

  Reference: https://dev.mysql.com/doc/refman/5.7/en/mysqldumpslow.html

• Question 9:

  You have issued this statement:

  GRANT PROXY ON 'a' FOR 'b';

  When user account 'b' issues a query, the query returns an access denied error.

  What could have caused that error?

  A. When connecting, user account 'b' is not entering the correct password for user account 'a'.

  B. You have not set the proxy_user variable in the configuration file.

  C. User account 'b' has not been granted permission to access the data being queried.

  D. User account 'a' has not been granted permission to access the data being queried.

  Correct Answer: A

  When a client connects to the server, the server determines the proper account based on the user name passed by the client program and the host from which the client connects.

  Reference: https://dev.mysql.com/doc/refman/8.0/en/proxy-users.html

• Question 10:

  A general purpose MySQL instance is configured with the following options:

  --slow-query-log --long-query-time=.0001 --log-queries-not-using-indexes --log-slow-admin-queries --general-log --log-bin --binlog-format=STATEMENT --innodb-flush-log-at-trx-commit=1

  Which three statements are true for most workloads? (Choose three.)

  A. The Slow Query Log records more data than the General Query Log.

  B. The General Query Log records more data than the Slow Query Log.

  C. The Slow Query Log records more data than the Binary Log.

  D. The Binary Log records more data than the General Query Log.

  E. The Binary Log records more data than the Slow Query Log.

  F. The General Query Log records more data than the Binary Log.

  Correct Answer: BCF