MYSQL 1Z0-874 問題集

質問 1：
Which of the following should be done to enable secure logging of events which may be needed for recovery operations and to track down security incidents? (Choose three)
A. Set the --encrypt-logs option
B. Enable the binary log
C. Enable the slow log
D. Enable the general log
E. Set permissions on log files so they are only readable by the user owning the mysql process
正解：B,D,E

質問 2：
Given the following MyISAM table structure:
mysql> desc city;
+-------------+----------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+----------+------+-----+---------+----------------+
| ID | int(11) | | PRI | NULL | auto_increment |
| Name | char(35) | | | | |
| CountryCode | char(3) | | | | |
| District | char(20) | | | | |
| Population | int(11) | | MUL | 0 | |
+-------------+----------+------+-----+---------+----------------+
And the following SQL statement: SELECT Population FROM city WHERE Population = 10000
ORDER BY Population LIMIT 5; which of the following statements best describes how MySQL
optimizer executes the query?
A. The optimizer will never read data from disk, since MySQL caches both data and index in the key buffer.
B. The optimizer uses the primary key column ID to read the index values, then uses the index on Population to filter the results. The optimizer will always choose to use a unique index first, then use a secondary index if available.
C. The optimizer uses the index on the Population column to search and filter the WHERE clause. A temporary table is used to perform a filesort on the results, and then only 5 records are returned to the client.
D. The optimizer uses the index on the Population column to search, filter and sort the Population column, and returns 5 records to the client. The optimizer does not need to read the data rows, and can return values from the index only because only those columns where specified in the SELECT statement.
E. The optimizer uses the index on the Population column to search, filter and sort the Population column, then returns 5 records to the client. The optimizer does not need to read the data rows, and can return values from the index only, because the index contains just integer values that form a leftmost prefix for the key.
正解：D

質問 3：
What kind of replication is supported by the MySQL server?
A. Multiple-master replication
B. MySQL doesn't support replication
C. Single file based clustering
D. Master to slave replication
正解：D

質問 4：
How can the SHOW PROCESSLIST command be helpful when optimizing queries?
A. It shows how the server processes a query.
B. It shows if a query is using an index or not.
C. It shows the percentage of processing power that each query is using on a server.
D. If checked periodically, it can reveal a queries that causes other queries to hang.
正解：D

質問 5：
Can multi-column FULLTEXT indexes be used? If so, when?
A. Yes, they should be used to search multiple columns simultaneously.
B. No, they can not be used.
C. Yes, they can be used to search either one or all of the indexed columns.
正解：A

質問 6：
Which of the following describe the correct single-statement syntax for allowing the existing user 'kofi'@'%' to perform SELECT, INSERT, DELETE and UPDATE actions on all tables in the world database?
A. GRANT world.* (SELECT, INSERT, DELETE, UPDATE) TO 'kofi'@'%'
B. Unless using ALL PRIVILEGES, it is not possible to assign more than one type of privilege at any one time.
C. GRANT SELECT, INSERT, DELETE, UPDATE ON world.* TO 'kofi'@'%';
D. GRANT (SELECT, INSERT, DELETE, UPDATE) ON world.* TO 'kofi'@'%'
E. GRANT SELECT INSERT DELETE UPDATE ON world.* TO 'kofi'@'%'
正解：C

質問 7：
The type of file system you chose may affect MySQL use and/or performance with regard to... (Choose three)
A. The number of users MySQL can handle.
B. Size limits of files.
C. Table opening time.
D. The type of storage engines that can be used.
E. Time to recover from a crash.
正解：B,C,E

質問 8：
In which ways can you set the query_cache_type option? (Choose three)
A. You can set it at runtime for the current connection with the following statement: SET SESSION query_cache_type=[0|1|2]
B. You can set it in the configuration file and restart the server.
C. You can set it at runtime for the entire server with the following statement: SET GLOBAL query_cache_type=[0|1|2]
正解：A,B,C

質問 9：
Consider the following: mysql> EXPLAIN SELECT Name FROM Country WHERE Population BETWEEN 1 AND 10000 *************************** 1. row *************************** id: 1 select_type: SIMPLE table: Country type: range possible_keys: i_pop key: i_pop key_len: 4 ref: NULL rows: 10 Extra: Using where
What is the meaning of the range value of the type column?
A. The optimizer has determined that only data from the very beginning or the very end of the table is needed
B. The type of index uses the range algorithm.
C. The index is used to select rows that fall between a range of index values.
D. There is a range of indexes that can be used.
正解：C