mysql故意放緩

Question

我有一個連接到數據庫的Java應用程序。在生產環境中，數據集非常大，所以應用程序非常慢，我想在開發環境中模擬（緩慢）。有沒有辦法，如何減慢mysql，所以響應時間更長？
我知道，我可以放大我的測試數據集，但大數據集的處理會佔用處理器週期，我寧願在MySQL中尋找「便宜」sleep s。

Answer 1

MySQL有一個SLEEP(duration)輔助功能，其中duration是秒數。

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

Answer 2

您可以MySQL數據庫文件複製到（慢，舊）USB閃存盤，並設置MySQL的設置DATADIR指向USB。我將MySQL數據目錄複製到USB密鑰並將datadir變量設置爲USB。

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

我猜想的innodb_flush_log_at_trx_commit設置爲1

# 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 

這樣每次更新，刪除，插入語句會導致I/O沖洗是很重要的。

Answer 3

要添加到SLEEP（）函數評論，下面是睡眠集成到任何SQL查詢時，您不能運行它作爲單獨的聲明一個簡單的方法：

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