我已将我的 MySQL 数据库从 5.6 迁移到 5.7 版。现在我遇到了性能问题。
两个版本都执行了特定的语句，我注意到 5.7 的速度要慢得多。特别是有大量数据。
即使是简单的选择语句也慢得多
5.6: 2,948 sec
5.7: 6,536 sec
在我的应用程序中，我有更复杂的语句需要更多时间来执行，所以它变得不可用。
我还注意到我的表的字段数在 5.7 中很重要，但在 5.6 中不重要。
my.ini 中的配置值没有改变。
要测试此问题，您可以使用以下代码：
#Create Tables
DROP TABLE IF EXISTS aTest;
DROP TABLE IF EXISTS sTest;
CREATE TABLE `aTest` (
`T_BETREFF` CHAR(40) NOT NULL DEFAULT '',
`T_DATUM` DATETIME NOT NULL DEFAULT '0000-00-00 00:00:00',
`T_ZEIT` CHAR(5) NOT NULL DEFAULT '',
`T_SACHBEARB` CHAR(2) NOT NULL DEFAULT '',
`SYS_UID` INT NOT NULL AUTO_INCREMENT,
`SYS_DATE` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
UNIQUE INDEX `TODO01` (`SYS_UID`),
INDEX `TODO02` (`T_SACHBEARB`)
)
COLLATE='latin1_swedish_ci'
ENGINE=MyISAM;
CREATE TABLE `sTest` (
`V_NR` CHAR(2) NOT NULL DEFAULT '',
`V_NAME` CHAR(30) NOT NULL DEFAULT '',
`SYS_UID` INT NOT NULL AUTO_INCREMENT,
`SYS_DATE` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
UNIQUE INDEX `S_VERK01` (`SYS_UID`),
UNIQUE INDEX `S_VERK02` (`V_NR`)
)
COLLATE='latin1_swedish_ci'
ENGINE=MyISAM;
#Fill Tables
DROP PROCEDURE IF EXISTS load_foo_atest_data;
DELIMITER //
CREATE PROCEDURE load_foo_atest_data()
BEGIN
DECLARE v_max int unsigned default 1000000;
DECLARE v_counter INT UNSIGNED DEFAULT 0;
WHILE v_counter < v_max DO
INSERT INTO aTest (T_BETREFF, T_DATUM, T_ZEIT, T_SACHBEARB) VALUES('TEST 1234,', NOW(), '00:00', v_counter DIV 100000 * 10);
IF (v_counter MOD 100000 = 0) THEN
INSERT INTO sTest (V_NR, V_NAME) VALUES(v_counter DIV 100000 * 10, CONCAT('TEST', v_counter));
END IF;
SET v_counter=v_counter+1;
END WHILE;
END //
DELIMITER ;
call load_foo_atest_data();
这是我的声明：
FLUSH TABLES;
SELECT * FROM atest
LEFT JOIN sTEST ON v_nr = t_sachbearb
GROUP BY atest.sys_uid
ORDER BY t_datum DESC, t_zeit DESC
编辑
解释结果：
5.6：
+----+-------------+--------+--------+------------- --+------------+----------+-------------- -----------------+---------+---------- ------------+ | 编号 | 选择类型 | 表| 类型 | 可能的键 | 关键 | key_len | 参考 | 行 | 额外 | +----+-------------+--------+--------+------------- --+------------+----------+-------------- -----------------+---------+---------- ------------+ | 1 | 简单 | 证明 | 全部 | 待办事项01 | 空 | 空 | 空 | 1000000 | 使用临时的；使用文件排序 | | 1 | 简单 | 测试 | eq_ref | S_VERK02 | S_VERK02 | 2 | obs_mysql_bergau_57test.test.T_SACHBEARB | 1 | 空 | +----+-------------+--------+--------+------------- --+------------+----------+-------------- -----------------+---------+---------- ------------+
5.7
+----+-------------+--------+------------+--------+ ---------------+----------+---------+---------- ------------------+---------+---------- -+----------------------------------+ | 编号 | 选择类型 | 表| 隔断 | 类型 | 可能的键 | 关键 | key_len | 参考 | 行 | 过滤 | 额外 | +----+-------------+--------+------------+--------+ ---------------+----------+---------+---------- ------------------+---------+---------- -+----------------------------------+ | 1 | 简单 | 证明 | 空 | 全部 | 待办事项01 | 空 | 空 | 空 | 1000000 | 100.00 | 使用临时的；使用文件排序 | | 1 | 简单 | 测试 | 空 | eq_ref | S_VERK02 | S_VERK02 | 2 | obs_mysql_bergau_57test.test.T_SACHBEARB | 1 | 100.00 | 空 | +----+-------------+--------+------------+--------+ ---------------+----------+---------+---------- ------------------+---------+---------- -+----------------------------------+
我的.ini：
# Other default tuning values
# MySQL Server Instance Configuration File
# ----------------------------------------------------------------------
# Generated by the MySQL Server Instance Configuration Wizard
#
#
# Installation Instructions
# ----------------------------------------------------------------------
#
# On Linux you can copy this file to /etc/my.cnf to set global options,
# mysql-data-dir/my.cnf to set server-specific options
# (@localstatedir@ for this installation) or to
# ~/.my.cnf to set user-specific options.
#
# On Windows you should keep this file in the installation directory
# of your server (e.g. C:\Program Files\MySQL\MySQL Server X.Y). To
# make sure the server reads the config file use the startup option
# "--defaults-file".
#
# To run run the server from the command line, execute this in a
# command line shell, e.g.
# mysqld --defaults-file="C:\Program Files\MySQL\MySQL Server X.Y\my.ini"
#
# To install the server as a Windows service manually, execute this in a
# command line shell, e.g.
# mysqld --install MySQLXY --defaults-file="C:\Program Files\MySQL\MySQL Server X.Y\my.ini"
#
# And then execute this in a command line shell to start the server, e.g.
# net start MySQLXY
#
#
# Guildlines for editing this file
# ----------------------------------------------------------------------
#
# In this file, you can use all long options that the program supports.
# If you want to know the options a program supports, start the program
# with the "--help" option.
#
# More detailed information about the individual options can also be
# found in the manual.
#
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
#
#
# CLIENT SECTION
# ----------------------------------------------------------------------
#
# The following options will be read by MySQL client applications.
# Note that only client applications shipped by MySQL are guaranteed
# to read this section. If you want your own MySQL client program to
# honor these values, you need to specify it as an option during the
# MySQL client library initialization.
# [client] no-beep
# pipe
# socket=0.0 port=3306
[mysql]
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=1 [mysqld]
# The next three options are mutually exclusive to SERVER_PORT below.
# 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
# Path to installation directory. All paths are usually resolved relative to this.
# basedir="C:/Program Files/MySQL/MySQL Server 5.7/"
# Path to the database root datadir=C:/ProgramData/MySQL/MySQL Server 5.7\Data
# The default character set that will be used when a new schema or table is
# created and no character set is defined character-set-server = latin1
# The default storage engine that will be used when create new tables when default-storage-engine = MYISAM
# Set the SQL mode to strict sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
# Enable Windows Authentication
# plugin-load=authentication_windows.dll
# General and Slow logging. log-output=FILE general-log=1 general_log_file="PC-THIEL.log" slow-query-log=1 slow_query_log_file="PC-THIEL-slow.log" long_query_time=10
# Binary Logging.
# log-bin
# Error Logging. log-error="PC-THIEL.err"
# Server Id. server-id=1
# Secure File Priv. secure-file-priv="C:/ProgramData/MySQL/MySQL Server 5.7/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=1000
# 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 = 2G
# 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=3G
# 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=6G
# 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 = 8G
# 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
# 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=1M
# 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=8M
# 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=1000
# 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 = 1
# 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
query_cache_limit = 30M collation-server = latin1_swedish_ci default_tmp_storage_engine = MYISAM
myisam_use_mmap concurrent_insert = AUTO