1Z0-874 Online Practice Questions and Answers

When working with replication, why might you want to stop the SQL thread on the slave while keeping the I/O thread running?

A. So that no changes are made while making backups.

B. So that events for the slave do not get backlogged on the master.

C. So that remaining events can be processed while not receiving new events from the master.

Which of the following statements are true regarding the slow query log?

A. The slow query log can be switched on with the log_slow_queries option.

B. The slow query log is always enabled.

C. The slow query log contains queries that don't utilize any index.

D. To have the slow query log contain queries that don't utilize any index, the log-queries-not- using-indexes option needs to be set.

E. The slow query log will contain queries that take more than 10 seconds.

F. The slow query log will contain queries that take more seconds than configured in the long_query_time option.

G. You can use the mysqldumpslow command line tool to summarize the content of the slow query log.

H. You can use the SHOW SLOW QUERIES statement to display all entries in the slow queries log.

Does the ordering of tables shown in an EXPLAIN output have any significance? Why?

A. Yes, it determines the table from which data will read first.

B. No, it sorts them alphabetically.

C. Yes, it sorts by the most optimized to the least optimized.

D. No, the order is determined by the order in which tables are specified in the statement being EXPLAINed.

Consider the following:

mysql> SELECT * FROM CountryLanguages;

+----+---------------+-------------+----------+

| ID | CountryName | CountryCode | Language |

+----+---------------+-------------+----------+

| 1 | United States | USA | English |

| 2 | United States | USA | Spanish |

| 3 | Mexico | MEX | Spanish |

| 4 | Canada | CAN | English |

| 5 | Canada | CAN | French |

+----+---------------+-------------+----------+

Which of the following describe how this table would look correctly normalized?

A. Table Countries: CountryCode, CountryNameTable Languages: LanguageID, LanguageTable CountryLanguage: CountryCode, LanguageID

B. Table Countries: CountryCode, CountryNameTable Languages: LanguageID, CountryCode, Language

C. Table Countries: CountryCode, CountryName, LanguageIDTable Languages: LanguageID, Language

D. Table Countries: CountryCode, CountryNameTable Languages: LanguageID, CountryCodeTable CountryLanguage: LanguageID, CountryCode, Language

Why should one preferably group multiple statements for InnoDB tables within a transaction whenever it is possible?

A. It minimizes bandwidth usage.

B. It helps keep log file sizes down.

C. It minimizes the amount of flush operations needed.

D. It helps reduce the chance of the transaction failing due to a bad query.

By default, mysqld's memory settings are...

A. There are no default memory settings for mysqld.

B. Set to a median value good for overall general use.

C. Rather consuming and should be decreased if possible.

D. Rather conservative and should be increased if possible.

Which of the following best describes what you might expect after disabling InnoDB at run time?

A. It will disable InnoDBs associated memory buffers and data structures, however it will not save any memory.

B. It will still enable InnoDBs associated memory buffers and data structures, however it will save memory.

C. It will disable InnoDBs associated memory buffers and data structures, which will save memory.

Which of the following are methods to improve performance?

A. Spreading single tables to different disks pointed to by a symbolic link.

B. Spreading whole databases to different disks pointed to by a symbolic link.

C. Moving the MySQL utilities such as mysqladmin to different disks pointed to by a symbolic link.

D. Moving less needed parts of the MySQL install such as the documentation or the test files to different disks pointed to by a symbolic link.

What kind of replication is supported by the MySQL server?

A. Multiple-master replication

B. Master to slave replication

C. Single file based clustering

D. MySQL doesn't support replication

Which of the following best describes what MASTER_LOG_FILE and MASTER_LOG_POS provides?

A. The path of the log file.

B. The file to log replication actions to.

C. The masters binary log name used for replication.

D. The position in the masters binary log in which to start replication.