单选题MySQL is installed on a Linux server and has the following configuration: What is the purpose of changing ownership of datadir to the ‘mysql’ user?（）A MySQL requires correct file ownership while remaining secureB MySQL needs to be run as the root use

A.MySQL requires correct file ownership while remaining secure

B.MySQL needs to be run as the root user, but file cannot be owned by it

C.MySQL cannot be run as the root user

A.A

B.B

C.C

D.D

A.mysqladmin-urootpasswordtest

B.mysql-urootpasswordtest

C.mysql-uroot-ptest

D.mysql-uroot-passwordtest

You execute the following statement in a Microsoft Windows environment. There are no conflicts in the path name definitions.C: \＞ mysqld – install Mysql56 – defaults – file = C :\my –opts.cnf What is the expected outcome?（）

A.Mysql is installed as the Windows service name Mysql56, and uses c: \my-opts.cnf as the configuration file

B.An error message is issued because – install is not a valid option for mysqld

C.A running Mysql 5.6 installation has its runtime configuration updated with the server variables set in c: \my-opts.cnf

D.Mysqld acts as an MSI installer and installs the Mysql 5.6 version, with the c: \my-opts.cnf configuration file

You have forgotten the root user account password. You decide to reset the password and execute the following:Shell＞ /etc/init.d/mysql stopShell＞ /etc/init.d/mysql start – skip-grant tablesWhich additional argument makes this operation safer?（）

A.–skip-networking, to prohibit access from remote locations

B.–reset-grant-tables, to start the server with only the mysql database accessible

C.–read-only,to set all data to read-only except for super users

D.–old-passwords, to start Mysql to use the old password format while running without the grant tables

Consider the query:Mysql＞ SET @run = 15;Mysql＞ EXPLAIN SELECT objective, stage, COUNT (stage)FROM iteminformationWHERE run=@run AND objective=’7.1’GROUP BY objective,stageORDER BY stage;The iteminformation table has the following indexes;Mysql＞ SHOW INDEXES FROM iteminformation:This query is run several times in an application with different values in the WHERE clause in a growing data set.What is the primary improvement that can be made for this scenario?（）

A.Do not pass a user variable in the WHERE clause because it limits the ability of the optimizer to use indexes

B.Add an index on the objective column so that is can be used in both the WHERE and GROUP BY operations

C.Drop the run_2 index because it has caused a conflict in the choice of key for this query

D.Execute the run_2 index because it has caused a conflict in the choice of key for this query

E.Add a composite index on (run,objective,stage) to allow the query to fully utilize an index

While reviewing the MySQL error log, you see occasions where MySQL has exceeded the number of file handles allowed to it by the operating system.Which method will reduce the number of file handles in use?（）

A.Activating the MySQL Enterprise thread pool plugin

B.Relocating your data and log files to separate storage devices

C.Disconnecting idle localhost client sessions

D.Implementing storage engine data compression options

Mysqldump was used to create a single schema backup; Shell> mysqldump –u root –p sakila > sakila2013.sqlWhich two commands will restore the sakila database without interfering with other running database?（）

A.Mysql＞ USE sakila; LOAD DATA INFILE ‘sakila2013.sql‘;

B.Shell＞ mysql –u root –p sakila sakila2013.sql

C.Shell＞ mysql import –u root –p sakila sakila2013.sql

D.Shell＞ mysql –u root -p –e ‘use sakila; source sakila2013.sql‘

E.Shell＞ mysql –u root –p –silent ＜ sakila2013.sql