7

我刚刚安装了具有 InnoDB 默认引擎的 MySQL 5.5，并实现 INSERT 查询真的很慢！禁用通用日志后，它变得更好了，但仍然很慢。我分析mysql以找到问题但没有机会。

这是比较这个的基准：

使用 500 行测试一个 (n) MISAM 表。 - 每秒 5866 次插入。- 每秒 128866 行读取。- 每秒 56306 次更新。

使用 500 行测试一个 (n) INNODB 表。 - 每秒 9 次插入。- 每秒 28539 行读取。- 每秒 4358 次更新。

与使用 MyISAM 的 5866 相比，我在 InnoDB 上有 9 个插入查询。

这是我的 my.ini（Windows 8 64 位）：

[mysql]

default-character-set=utf8
no-auto-rehash

[mysqld]
max_allowed_packet = 500M
table_open_cache = 512

# 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 5.5\"

# Path to the database root
datadir="D:\MySQL Datafiles\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=utf8

# 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=0
#general_log_file="POOYA.log"
#slow-query-log=0
#slow_query_log_file="POOYA-slow.log"
#long_query_time=10

#innodb_flush_log_at_trx_commit = 2

# Binary Logging.
# log-bin

# Error Logging.
log-error="POOYA.err"


max_connections=100

query_cache_size=32M

table_cache=512

tmp_table_size=64M

thread_cache_size=8

myisam_max_sort_file_size=100G

myisam_sort_buffer_size=64M

key_buffer_size=256M

# 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=1M
read_rnd_buffer_size=4M

# This buffer is allocated when MySQL needs to rebuild the index in
# REPAIR, OPTIMZE, ALTER table statements as well as in LOAD DATA INFILE
# into an empty table. It is allocated per thread so be careful with
# large settings.
sort_buffer_size=1M

#*** 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=64M

# 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=8M

# 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=512M

# 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=49M

# 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
[mysqldump]
quick
max_allowed_packet = 16M

[myisamchk]
key_buffer_size = 128M
sort_buffer_size = 128M
read_buffer = 2M
write_buffer = 2M

[mysqlhotcopy]
interactive-timeout

我已经编辑了这个文件以获得高性能，mysql 5.1也没有任何问题

4

3 回答 3

9

根据要求，提交级别的日志记录通常会导致大量磁盘压力，从而大大降低了带有 inno 的 mysql 实例上的数据吞吐量。

将 mysql.ini 设置为innodb_flush_log_at_trx_commit = 0（或 2）通常可以解决此问题。

请注意，ACID 规则希望该值为 1...

于 2013-01-02T12:07:59.580 回答
1

您也可以使用以下命令直接在 MySQL 命令行上进行设置：

SET GLOBAL innodb_flush_log_at_trx_commit = 0;
于 2013-11-18T11:48:21.123 回答
1

您是否一次添加一行？

如果您为每个事务添加多行，那将有很大帮助。

# 1:
INSERT INTO my_table VALUES (1, "A");
INSERT INTO my_table VALUES (2, "B");

# 2:
INSERT INTO my_table VALUES (1, "A"),(2, "B");

# 3:
BEGIN;
INSERT INTO my_table VALUES (1, "A");
INSERT INTO my_table VALUES (2, "B");
COMMIT;

在 InnoDB 中 #2 和 #3 将比 #1 快得多。

#2 对 MyISAM 也有帮助，但作用不大。粗略的数字，我看到这将 MyISAM 提高了 2 倍，将 InnoDB 提高了 100 倍。

于 2014-07-19T15:38:21.580 回答