问数据库性能下降，升级到MySQL 8.0.20之后

EN

key_buffer_size = 2G
max_allowed_packet = 1M

;Added to reduce memory used (minimum is 400)
table_definition_cache = 600

sort_buffer_size = 4M
net_buffer_length = 8K
read_buffer_size = 2M
read_rnd_buffer_size = 2M
myisam_sort_buffer_size = 2G
;Path to mysql install directory
basedir="c:/wamp64/bin/mysql/mysql8.0.20"
log-error="c:/wamp64/logs/mysql.log"
;Verbosity Value  1 Errors only, 2  Errors and warnings , 3 Errors, warnings, and notes
log_error_verbosity=2
;Path to data directory
datadir="c:/wamp64/bin/mysql/mysql8.0.20/data"


;slow_query_log = ON
;slow_query_log_file = "c:/wamp64/logs/slow_query.log"

;Path to the language
;See Documentation:
; http://dev.mysql.com/doc/refman/5.7/en/error-message-language.html
lc-messages-dir="c:/wamp64/bin/mysql/mysql8.0.20/share"
lc-messages=en_US

; The default storage engine that will be used when create new tables
default-storage-engine=InnoDB
; New for MySQL 5.6 default_tmp_storage_engine if skip-innodb enable
; default_tmp_storage_engine=MYISAM

;To avoid warning messages
secure_file_priv="c:/wamp64/tmp"
skip-ssl

explicit_defaults_for_timestamp=true

; Set the SQL mode to strict
sql-mode=""
;sql-mode="STRICT_ALL_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_ZERO_DATE,NO_ZERO_IN_DATE,NO_AUTO_CREATE_USER"

;skip-networking

; Disable Federated by default
skip-federated

; Replication Master Server (default)
; binary logging is required for replication
;log-bin=mysql-bin

; binary logging format - mixed recommended
;binlog_format=mixed

; required unique id between 1 and 2^32 - 1
; defaults to 1 if master-host is not set
; but will not function as a master if omitted
server-id = 1

; Replication Slave (comment out master section to use this)

; New for MySQL 5.6 if no slave
skip-slave-start


; The InnoDB tablespace encryption feature relies on the keyring_file
; plugin for encryption key management, and the keyring_file plugin
; must be loaded prior to storage engine initialization to facilitate
; InnoDB recovery for encrypted tables. If you do not want to load the
; keyring_file plugin at server startup, specify an empty string.
early-plugin-load=""

;innodb_data_home_dir = C:/mysql/data/
innodb_data_file_path = ibdata1:12M:autoextend
;innodb_log_group_home_dir = C:/mysql/data/
;innodb_log_arch_dir = C:/mysql/data/

; You can set .._buffer_pool_size up to 50 - 80 %
; of RAM but beware of setting memory usage too high
innodb_buffer_pool_size = 4G

; Set .._log_file_size to 25 % of buffer pool size
innodb_log_file_size = 16M
innodb_log_buffer_size = 8M
innodb_thread_concurrency = 64
innodb_flush_log_at_trx_commit = 2

log_bin_trust_function_creators = 1;

innodb_lock_wait_timeout = 120
innodb_flush_method=normal
innodb_use_native_aio = true

innodb_flush_neighbors = 2
innodb_autoinc_lock_mode = 1

[mysqldump]
quick
max_allowed_packet = 16M

[mysql]
no-auto-rehash
; Remove the next comment character if you are not familiar with SQL
;safe-updates

[isamchk]
key_buffer_size = 20M
sort_buffer_size = 20M
read_buffer_size = 2M
write_buffer_size = 2M

[myisamchk]
key_buffer_size = 256M ;20M hys
sort_buffer_size_size = 20M
read_buffer_size = 2M
write_buffer_size = 2M

[mysqlhotcopy]
interactive-timeout

[mysqld]
port = 3306
skip-log-bin
default_authentication_plugin= mysql_native_password

max_connections = 400
max_connect_errors = 100000

innodb_read_io_threads = 32
innodb_write_io_threads = 8
innodb_thread_concurrency = 64