8.2.1. 前言
MySQL 程序安装属于默认安装，其中配置文件在 windoes 下的文件名为：my.ini。
配置文件所处位置：
- windows:
C:\ProgramData\MySQL\MySQL Server ${version}\my.ini
8.2.2. 完整配置文件
# 以下选项会被MySQL客户端应用读取。
# 注意只有MySQL附带的客户端应用程序保证可以读取这段内容。
# 如果你想你自己的MySQL应用程序获取这些值。
# 需要在MySQL客户端库初始化的时候指定这些选项。
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
# *** DO NOT EDIT THIS FILE. It's a template which will be copied to the
# *** default location during install, and will be replaced if you
# *** upgrade to a newer version of MySQL.
[client]
# pipe
# socket=0.0
port=3306
default-character-set=utf8
[mysql]
no-beep
default-character-set=utf8
# SERVER SECTION
# ----------------------------------------------------------------------
#
# The following options will be read by the MySQL Server. Make sure that
# you have installed the server correctly (see above) so it reads this
# file.
#
# server_type=2
[mysqld]
# 不在 TCP/IP 端口上进行监听.
# 如果所有的进程都是在同一台服务器连接到本地的 mysqld,
# 这样设置将是增强安全的方法
# 所有 mysqld 的连接都是通过 Unix Sockets 或者命名管道进行的.
# 注意在 Windows下如果没有打开命名管道选项而只是用此项
# (通过 “enable-named-pipe” 选项) 将会导致 MySQL 服务没有任何作用!
# skip-networking
# enable-named-pipe
# shared-memory
# shared-memory-base-name=MYSQL
# The Pipe the MySQL Server will use
# socket=MYSQL
# The TCP/IP Port the MySQL Server will listen on
port=3306
# 使用给定目录作为根目录(安装目录)。
# basedir="C:/Program Files/MySQL/MySQL Server 5.6/"
# 从给定目录读取数据库文件。
datadir=C:/ProgramData/MySQL/MySQL Server 5.6/Data
# 默认编码集设置，当一个任务事件或者数据表被创建是没有被指定编码集时则采用该编码集
character-set-server=utf8
# The default storage engine that will be used when create new tables when
default-storage-engine=INNODB
# Set the SQL mode to strict
sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
# General and Slow logging.
log-output=FILE
general-log=0
general_log_file="MINGRN.log"
slow-query-log=1
slow_query_log_file="MINGRN-slow.log"
long_query_time=10
# 二进制日志
# log-bin
# 错误日志
log-error="MINGRN.err"
# Server Id.
server-id=1
# Secure File Priv.
secure-file-priv="C:/ProgramData/MySQL/MySQL Server 5.6/Uploads"
# The maximum amount of concurrent sessions the MySQL server will
# allow. One of these connections will be reserved for a user with
# SUPER privileges to allow the administrator to login even if the
# connection limit has been reached.
max_connections=151
# Query cache is used to cache SELECT results and later return them
# without actual executing the same query once again. Having the query
# cache enabled may result in significant speed improvements, if your
# have a lot of identical queries and rarely changing tables. See the
# "Qcache_lowmem_prunes" status variable to check if the current value
# is high enough for your load.
# Note: In case your tables change very often or if your queries are
# textually different every time, the query cache may result in a
# slowdown instead of a performance improvement.
query_cache_size=0
# The number of open tables for all threads. Increasing this value
# increases the number of file descriptors that mysqld requires.
# Therefore you have to make sure to set the amount of open files
# allowed to at least 4096 in the variable "open-files-limit" in
# section [mysqld_safe]
table_open_cache=2000
# Maximum size for internal (in-memory) temporary tables. If a table
# grows larger than this value, it is automatically converted to disk
# based table This limitation is for a single table. There can be many
# of them.
tmp_table_size=593M
# How many threads we should keep in a cache for reuse. When a client
# disconnects, the client's threads are put in the cache if there aren't
# more than thread_cache_size threads from before. This greatly reduces
# the amount of thread creations needed if you have a lot of new
# connections. (Normally this doesn't give a notable performance
# improvement if you have a good thread implementation.)
thread_cache_size=10
#*** MyISAM Specific options
# The maximum size of the temporary file MySQL is allowed to use while
# recreating the index (during REPAIR, ALTER TABLE or LOAD DATA INFILE.
# If the file-size would be bigger than this, the index will be created
# through the key cache (which is slower).
myisam_max_sort_file_size=100G
# If the temporary file used for fast index creation would be bigger
# than using the key cache by the amount specified here, then prefer the
# key cache method. This is mainly used to force long character keys in
# large tables to use the slower key cache method to create the index.
myisam_sort_buffer_size=2G
# Size of the Key Buffer, used to cache index blocks for MyISAM tables.
# Do not set it larger than 30% of your available memory, as some memory
# is also required by the OS to cache rows. Even if you're not using
# MyISAM tables, you should still set it to 8-64M as it will also be
# used for internal temporary disk tables.
key_buffer_size=8M
# Size of the buffer used for doing full table scans of MyISAM tables.
# Allocated per thread, if a full scan is needed.
read_buffer_size=64K
read_rnd_buffer_size=256K
#*** INNODB Specific options ***
# innodb_data_home_dir=0.0
# Use this option if you have a MySQL server with InnoDB support enabled
# but you do not plan to use it. This will save memory and disk space
# and speed up some things.
# skip-innodb
# Additional memory pool that is used by InnoDB to store metadata
# information. If InnoDB requires more memory for this purpose it will
# start to allocate it from the OS. As this is fast enough on most
# recent operating systems, you normally do not need to change this
# value. SHOW INNODB STATUS will display the current amount used.
innodb_additional_mem_pool_size=32M
# If set to 1, InnoDB will flush (fsync) the transaction logs to the
# disk at each commit, which offers full ACID behavior. If you are
# willing to compromise this safety, and you are running small
# transactions, you may set this to 0 or 2 to reduce disk I/O to the
# logs. Value 0 means that the log is only written to the log file and
# the log file flushed to disk approximately once per second. Value 2
# means the log is written to the log file at each commit, but the log
# file is only flushed to disk approximately once per second.
innodb_flush_log_at_trx_commit=1
# The size of the buffer InnoDB uses for buffering log data. As soon as
# it is full, InnoDB will have to flush it to disk. As it is flushed
# once per second anyway, it does not make sense to have it very large
# (even with long transactions).
innodb_log_buffer_size=16M
# InnoDB, unlike MyISAM, uses a buffer pool to cache both indexes and
# row data. The bigger you set this the less disk I/O is needed to
# access data in tables. On a dedicated database server you may set this
# parameter up to 80% of the machine physical memory size. Do not set it
# too large, though, because competition of the physical memory may
# cause paging in the operating system. Note that on 32bit systems you
# might be limited to 2-3.5G of user level memory per process, so do not
# set it too high.
innodb_buffer_pool_size=5G
# Size of each log file in a log group. You should set the combined size
# of log files to about 25%-100% of your buffer pool size to avoid
# unneeded buffer pool flush activity on log file overwrite. However,
# note that a larger logfile size will increase the time needed for the
# recovery process.
innodb_log_file_size=48M
# Number of threads allowed inside the InnoDB kernel. The optimal value
# depends highly on the application, hardware as well as the OS
# scheduler properties. A too high value may lead to thread thrashing.
innodb_thread_concurrency=17
# The increment size (in MB) for extending the size of an auto-extend InnoDB system tablespace file when it becomes full.
innodb_autoextend_increment=64
# The number of regions that the InnoDB buffer pool is divided into.
# For systems with buffer pools in the multi-gigabyte range, dividing the buffer pool into separate instances can improve concurrency,
# by reducing contention as different threads read and write to cached pages.
innodb_buffer_pool_instances=8
# Determines the number of threads that can enter InnoDB concurrently.
innodb_concurrency_tickets=5000
# Specifies how long in milliseconds (ms) a block inserted into the old sublist must stay there after its first access before
# it can be moved to the new sublist.
innodb_old_blocks_time=1000
# It specifies the maximum number of .ibd files that MySQL can keep open at one time. The minimum value is 10.
innodb_open_files=300
# When this variable is enabled, InnoDB updates statistics during metadata statements.
innodb_stats_on_metadata=0
# When innodb_file_per_table is enabled (the default in 5.6.6 and higher), InnoDB stores the data and indexes for each newly created table
# in a separate .ibd file, rather than in the system tablespace.
innodb_file_per_table=1
# Use the following list of values: 0 for crc32, 1 for strict_crc32, 2 for innodb, 3 for strict_innodb, 4 for none, 5 for strict_none.
innodb_checksum_algorithm=0
# The number of outstanding connection requests MySQL can have.
# This option is useful when the main MySQL thread gets many connection requests in a very short time.
# It then takes some time (although very little) for the main thread to check the connection and start a new thread.
# The back_log value indicates how many requests can be stacked during this short time before MySQL momentarily
# stops answering new requests.
# You need to increase this only if you expect a large number of connections in a short period of time.
back_log=80
# If this is set to a nonzero value, all tables are closed every flush_time seconds to free up resources and
# synchronize unflushed data to disk.
# This option is best used only on systems with minimal resources.
flush_time=0
# The minimum size of the buffer that is used for plain index scans, range index scans, and joins that do not use
# indexes and thus perform full table scans.
join_buffer_size=256K
# The maximum size of one packet or any generated or intermediate string, or any parameter sent by the
# mysql_stmt_send_long_data() C API function.
max_allowed_packet=4M
# If more than this many successive connection requests from a host are interrupted without a successful connection,
# the server blocks that host from performing further connections.
max_connect_errors=100
# Changes the number of file descriptors available to mysqld.
# You should try increasing the value of this option if mysqld gives you the error "Too many open files".
open_files_limit=4161
# Set the query cache type. 0 for OFF, 1 for ON and 2 for DEMAND.
query_cache_type=0
# If you see many sort_merge_passes per second in SHOW GLOBAL STATUS output, you can consider increasing the
# sort_buffer_size value to speed up ORDER BY or GROUP BY operations that cannot be improved with query optimization
# or improved indexing.
sort_buffer_size=256K
# The number of table definitions (from .frm files) that can be stored in the definition cache.
# If you use a large number of tables, you can create a large table definition cache to speed up opening of tables.
# The table definition cache takes less space and does not use file descriptors, unlike the normal table cache.
# The minimum and default values are both 400.
table_definition_cache=1400
# Specify the maximum size of a row-based binary log event, in bytes.
# Rows are grouped into events smaller than this size if possible. The value should be a multiple of 256.
binlog_row_event_max_size=8K
# If the value of this variable is greater than 0, a replication slave synchronizes its master.info file to disk.
# (using fdatasync()) after every sync_master_info events.
sync_master_info=10000
# If the value of this variable is greater than 0, the MySQL server synchronizes its relay log to disk.
# (using fdatasync()) after every sync_relay_log writes to the relay log.
sync_relay_log=10000
# If the value of this variable is greater than 0, a replication slave synchronizes its relay-log.info file to disk.
# (using fdatasync()) after every sync_relay_log_info transactions.
sync_relay_log_info=10000
# Load mysql plugins at start."plugin_x ; plugin_y".
# plugin_load
# 默认配置文件中没有该配置需要进行增加该配置。
# 如果不增加该配置，在数据库中创建一个事件后将不会自动触发。该配置用于开启事件。
event_scheduler=ON
8.2.3. 修改数据库编码格式
在mysql 5.5 之前，UTF-8编码只支持1-3个字节，支持BMP这部分的Unicode编码区。
从MySQL 5.5开始，可以支持4个字节UTF编码 utf8mb4 ，一个字符能够支持更多的字符集，也能够支持更多表情符号。
表情为四个字节，所以在存在 emoji 的场景下需要需要使用该编码集。
utf8mb4兼容utf8，且比utf8能表示更多的字符，是utf8字符集的超集。所以现在一些新的业务，比如 ISO 等，会将 MySQL 数据库的字符集设置为 utf8mb4。
现在将编码集设置为 utf8mb4，需要修改如下配置：
[client]
# 服务端默认编码格式，默认为 `utf-8`
default-character-set = utf8mb4
[mysql]
# 默认字符编码，默认 `utf-8`
default-character-set = utf8mb4
[mysqld]
# 默认编码集设置，当一个任务事件或者数据表被创建是没有被指定编码集时则采用该编码集
character-set-server = utf8mb4
以上修改完成后重启 mysql 服务，在 MySQL Command Line Client 中输入如下命令即可查看数据库编码集：
SHOW VARIABLES LIKE 'character%';
输出结果如下所示：
+--------------------------+---------------------------------------------------------+
| Variable_name | Value |
+--------------------------+---------------------------------------------------------+
| character_set_client | utf8mb4 |
| character_set_connection | utf8mb4 |
| character_set_database | utf8mb4 |
| character_set_filesystem | binary |
| character_set_results | utf8mb4 |
| character_set_server | utf8mb4 |
| character_set_system | utf8 |
| character_sets_dir | C:\Program Files\MySQL\MySQL Server 5.6\share\charsets\ |
+--------------------------+---------------------------------------------------------+
8 rows in set (0.00 sec)
可即看到编码格式被修改为 utf8mb4。
现在在命令行中执行进行 emoji 数据插入：
INSERT INTO `sys_role`(`id`, `role_name`, `role_type`, `status`, `deleted`, `sort`, `create_time`, `update_time`, `description`)
VALUES ('62eedcd2f47e11e8881d5615b7fd4e65', 'Emoji测试😀', '6888bc90f47e11e8881d5615b7fd4e65', 1, 1, 1, '2018-11-30 17:00:11', '2018-11-30 17:00:13', NULL);
mysql> select * from sys_role;
+----------------------------------+-----------------+----------------------------------+--------+---------+------+---------------------+---------------------+-------------+
| id | role_name | role_type | status | deleted | sort | create_time | update_time | description |
+----------------------------------+-----------------+----------------------------------+--------+---------+------+---------------------+---------------------+-------------+
| 3a74e039f47e11e8881d5615b7fd4e65 | 超级管理员 | 48264450f47e11e8881d5615b7fd4e65 | 1 | 1 | 1 | 2018-11-30 17:00:11 | 2018-11-30 17:00:13 | NULL |
| 62eedcd2f47e11e8881d5615b7fd4e65 | Emoji测试😀 | 6888bc90f47e11e8881d5615b7fd4e65 | 1 | 1 | 1 | 2018-11-30 17:00:11 | 2018-11-30 17:00:13 | NULL |
+----------------------------------+-----------------+----------------------------------+--------+---------+------+---------------------+---------------------+-------------+
2 rows in set (0.00 sec)
可以看到数据被正常插入，如果编码集设置为 utf-8 在插入是会提示异常。
参考