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?（）

多项选择题Which two options describe how MySQL Server allocates memory?（）

A.Thread memory is pre-allocated up to thread_cache_size for performance
B.Each connection may have its own per-thread memory allocations
C.Global memory resources are allocated at server startup
D.Each thread allocates memory from a global pool

多项选择题Which two statements describe the behavior of the server's SQL mode?（）

A.The server's SQL mode determines how the server should behave when performing data validation check and interpreting different forms of syntax
B.The server's SQL mode determines whether the server should be read-only or should accept commands such as INSERT and UPDATE
C.The server's SQL mode can be changed at the session level with a SET SESSION sql_mode="new_value" command
D.The server's SQL mode, when globally set on a slave server, applies to events sent from the master

多项选择题A MySQL replication slave is set up as follows: User all InnoDB tables Receives ROW-based binary logs Has the read-only option The replication slave has been found in an error state. You check the MySQL error log file and find the following entries: 2013-08-27 13:55:44 9056 [ERROR] Slave SQL: Could not execute Write_rows event on table test.tl; Duplicate entry ‘3’ for key’PRIMARY’ , Error_code: 1062; handler error HA_ERR_FOUND_DUPP_KEY; the event’s master log 56_master-bin.000003, end_log_pas 653, Error_code: 1062 2013-08-27 13:55:44 9056 [Warning] Salve: Duplicate entry ‘3’ for key ‘PRIMARY’ Error_code: 1062 2013-08-27 13:55:44 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 496 What are two possible causes for this error to occur?（）

A.The slave was created with mysqldump –u root –p – skip-lock-table—all-databases > /data/data.sql
B.The slave user does have INSERT, UPDATE, or DELETE permission and cannot execute the write_rows function
C.For tables with UNIQUE keys, statement-based replication must be used maintain integrity
D.The root user on the slave has executed FLUSH LOGS, causing the relay-log to doublewrite
E.The applications have the SUPER privilege, which allows them to update rows

多项选择题Compare a typical Distributed Replicated Block Device (DRBD) with MySQL Standard Replication using master-slave replication. Which two statements are correct?（）

A.Both technologies guarantee an identical copy of data on the secondary node
B.Only MySQL can maintain a time-delayed copy of data on the secondary node
C.Both technologies use the TCP/IP stack as their primary transmission medium
D.DRBD uses shared-disk technology

多项选择题A general purpose MySQL instance is configured with the following options: —log-slow-queries —long-query-time=,0001 —log-slow-admin-queries —general-log —log-bin —binlog-format=STATEMENT —innodb-flush-log-at-trx-commit=1 Which three statements are true（）。

A.The General Query Log records more data than the Binary Log
B.The binary Log records more data than the General Query Log
C.The Slow Query Log records more data than the General Query Log
D.The General Query Log records more data than the Slow Query Log
E.The Slow Query Log records more data than the Binary Log
F.The Binary Log records more data than the Slow Query Log