Question

我有一个连接数据库的Java应用程序。在生产环境中，数据集非常大，因此应用程序非常慢，我想在开发环境中模拟（缓慢）。有没有办法，如何减慢mysql，所以响应时间更长？我知道，我可以扩大我的测试数据集，但是大数据集的处理会占用处理器周期，我宁愿在sleep中搜索能够“廉价”MySQL的东西。< / p>

Answer 1

MySQL有一个SLEEP(duration)杂项函数，其中duration是秒数。

来源：http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_sleep

Answer 2

您可以将MySQL数据库文件复制到（慢，旧）usb密钥，并将MySQL的设置datadir设置为指向usb。我将MySQL数据目录复制到usb键并将datadir变量设置为usb。

#Path to the database root
#datadir="C:/Program Files (x86)/MySQL/MySQL Server 5.0/Data/"
datadir = "E:/data"

我认为将innodb_flush_log_at_trx_commit设置为1非常重要。

# 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

这样每次更新，删除，插入语句都会导致I / O刷新。

Answer 3

要添加到SLEEP（）函数注释，这里可以轻松地将睡眠集成到任何SQL查询中，而不能将其作为单独的语句运行：

LEFT JOIN (SELECT SLEEP(30)) as `sleep` ON 1=1

mysql故意放慢速度

3 个答案: