问题:单选题You have taken a Logical Volume Manager (LVM) snapshot backup of a volume that contains the MySQL data directory. Why is it important to remove snapshots after completing a RAW backup in this way?()A The snapshot size will continue to grow as changes to the volume are madeB The snapshots take a significant amount of disk space as they are a duplicate copy of the dataC The system can only support one snapshot per volume, and you need to remove it to be able to take your next backupD The system keeps a copy of changes in memory and can cause an out of memory event
Monday, April 8, 2024
问题:单选题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 pluginB Relocating your data and log files to separate storage devicesC Disconnecting idle localhost client sessionsD Implementing storage engine data compression options
Tuesday, August 15, 2023
问题:单选题You have forgotten the root user account password. You decide to reset the password and execute the following: Shell> /etc/init.d/mysql stop Shell> /etc/init.d/mysql start – skip-grant tables Which additional argument makes this operation safer?()A –skip-networking, to prohibit access from remote locationsB –reset-grant-tables, to start the server with only the mysql database accessibleC –read-only,to set all data to read-only except for super usersD –old-passwords, to start Mysql to use the old password format while running without the grant tables
Tuesday, April 9, 2024
问题:单选题What is true regarding InnoDB locking?()A InnoDB uses row and table-level locks, but row locks are not escalatesB InnoDB locks only those rows that are updatedC InnoDB only uses row locks, not page or table-level locksD InnoDB row locks may be escalated to page or table-level locksE InnoDB uses row-level or table-level locks depending on the number of rows affected
Monday, May 29, 2023
问题:单选题You adjust a default configuration to the following /etc/my.cnf on a Linux installation:[mysqld] Loq-bin Binrylog_format=ROW You do not notice the spelling error in binrylog_format and restart your production server. How does the MySQL server behave with incorrectly spelled options?()A Mysqld uses internal configuration versioning and reverts to the previous configurationB When using mysql_config_editor for configuration adjustments, it detects incorrect syntax and typing mistakesC The mysqld_safe script skips the unknown variable and starts using the remaining configuration changesD Mysqld prints to the error log about an unknown variable, and then exits
问题:多选题Which two statements are true about setting the per-thread buffers higher than required?()AMore memory per thread is beneficial in all scenariosBIt causes increased overhead due to initial memory allocationCIt can affect system stability during peak load times, due to swappingDIt requires increasing the thread_cache_size variable
Thursday, January 4, 2024
问题:多选题What are three facts about backups with mysqldump?()ACan back up a remote database serverBAllow a consistent backup to be takenCAre always faster to restore than binary backupsDAre able to back up specific items within a databaseECreate automatically compressed backupsFWill lock all storage engines for duration of backup
问题:多选题Consider the events_% tables in performance Schema. Which two methods will clear or reset the collected events in the tables?()AUsing DELETE statements, for example, DELETE FROM performance_schema.events_watis_currentBUsing the statement RESET PERFORMANCE CACHECUsing the statement FLUSH PERFORMANCE CACHEDUsing TRUNCATE statements, for example, TRUNATE TABLE performance_schema.events_waits_currentEDisabling and re-enabling all instrumentsFRestarting Mysql
Wednesday, December 20, 2023
问题:单选题ROW-based replication has stopped working. You investigate the error log file and find the following entries: 2013-08-27 14:15:47 9056 [ERROR] Slave SQL: Could not execute Delete_rows event on table test.t1; Can't find record in 't1', Error_code: 1032; handler error HA_ERR_KEY_NOT_FOUND; the event's master log 56_master-bin. 000003, end_log_pos 851, Error_code: 1032 2013-08-27 14:15:47 9056 [warning] Slave: Can't find record in 't1' Error_code: 1032 2013-08-27 14:15:47 9056 [ERROR] Error running query, slave SQL thread aborted. Fix the problem, and restart the slave SQL thread with "SLAVE START". We stopped at log '56_masterbin. 000003' position 684 Why did you receive this error?()A The slave SQL thread does not have DELETE privileges to execute on test.t1 table.sB The table definition on the slave -litters from the masterC Multi-threaded replication slaves can have temporary errors occurring for cross database updatesD The slave SQL thread attempted to remove a row from the test.t1 table, but the row did not exist
问题:多选题Mysqldump was used to create a single schema backup; Shell> mysqldump –u root –p sakila > sakila2013.sql Which two commands will restore the sakila database without interfering with other running database?()AMysql> USE sakila; LOAD DATA INFILE 'sakila2013.sql';BShell> mysql –u root –p sakila sakila2013.sqlCShell> mysql import –u root –p sakila sakila2013.sqlDShell> mysql –u root -p –e 'use sakila; source sakila2013.sql'EShell> mysql –u root –p –silent < sakila2013.sql
Thursday, May 2, 2024
问题:单选题Review the definition of the phone_list view. CHEATE OR REPLACE ALGORITHM=MERGE DEFINER= 'root'@localhost' SQL SECURITY DEFINER VIEW 'phone_list' AS SELECT e . id as id 'e . first_name AS 'first_name' 'e . last_name AS 'last_name' 'coalesce ( ph1.phone_no, ' – ') AS 'office_no' 'coalesce (ph2 .phone_no, ' – ') AS 'cell_no' FROM employees e LEFT JOIN employee_phone ph1 ON ph1.emp_id = e.id AND ph1.type = 'office' LEFT JOIN employee_phone ph2 ON ph2 .emp_id = e.id AND ph2 .type = 'mobile' The tables employees and employee_phone are InnoDB tables; all columns are used in this view. The contents of the phone_list view are as follows: Mysql> select * from phone_list; 1 row in set (0.00 sec) Which method can you use to change the cell_no value to '555-8888' for John Doe?()A INSERT INTO employee_phone (emp_id, phone_no, type) VALUES (1, '555-8888','mobile')B UPDATE phone_list SET cell_name '555-8888' WHERE first_name= 'John' and last_name= 'Doe'C DELETE FROM phone_list WHERE first_name= 'John' and last_name= 'Doe'; INSERT INTO phone_list (first_name, last_name, office_no, cell_no) VALUES ('John' , 'Doe' , 'x1234' , '555-8888)D UPDATE employee_phone SET phone_no= '555-8888' where emp_id=1
问题:单选题You want to start monitoring statistics on the distribution of storage engines that are being used and the average sizes of tables in the various databases. Some details are as follows: The Mysql instance has 400 databases. Each database on an average consists of 25-50 tables. You use the query: SELECT TABLE_SCHEMA, 'ENGINE', COUNT (*), SUM(data_length) total_size FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE= 'BASE TABLE' GROUP BY TABLE_SCHEMA, 'ENGINE' ; Why is this query slow to execute?()A Collecting information requires large numbers of locks on various INFORMATION_SCHEMA tablesB Aggregating details from various storage engine caches for the final output is time consumingC Collecting information requires various disk-level operations and is time consumingD Counting and summarizing all table pages in the InnoDB shared tablespace is time consuming
问题:单选题Consider the following: Which statement best describes the meaning of the value for the key_len column?()AIt shows the total size of the index rowBIt shows how many columns in the index are examinedCIt shows the number of characters indexed in the keyDIt shows how many bytes will be used from each index row
问题:多选题What are two methods of taking a binary backup of a Mysql Server using InnoDB storage engine?()AFile system snapshotsBMysqldumpslowCMysqlhotcopyDMysqldump with – binary-data optionEMysql Enterprise Backup
Friday, December 15, 2023
问题:多选题Which two options describe how MySQL Server allocates memory?()AThread memory is pre-allocated up to thread_cache_size for performanceBEach connection may have its own per-thread memory allocationsCGlobal memory resources are allocated at server startupDEach thread allocates memory from a global pool
问题:单选题You use—login-path to access a MySQL server on a Linux installation. Which statement is true about the – login-path option that is created by using mysql_config_editor?()A All system users have access to the MySQL server via—login path localB login-path can be used only for MySQL servers running on a local machineC login-path allows you to provide login credentials without passing clear text passwords on the command lineD When using – login-path to connect to a remote MySQL server, the remote server version must be 5.6 or later
问题:多选题Which two requirements would lead towards a high availability solution?()AWhen uptime is criticalBWhen data must be refactoredCWhen application concurrency is staticDWhen data loss is unacceptableEWhen application is a single point of failure
问题:单选题You have a server that has very limited memory but has a very large table. You will use mysqldump to back up this table. Which option will ensure mysqldump will process a row at a time instead of buffering a set of rows?()A — quickB — skip-bufferC — single-transactionD — tab