Mysql：在我的本地機器上觀察到插入和更新都很慢

Question

這是Uday。我用一個innodb小表對寫入性能有問題。

There is a table called "wlists" on my local machine(mysql 5.1.X). 
    It has 5 attributes and has less than 1000 rows. 
    By default, innodb_flush_log_at_trx_commit is set to 1 ; 

    Now the thing is that 
    every insert/update it is taking 0.04 seconds, 
    this is horrible because i can do just 54K inserts per hour. 

    When innodb_flush_log_at_trx_commit set to 2, its working fine. 

如何獲得與innodb_flush屬性設置爲1相同的性能只.. ..？

Here are some other details that may help in addressing this: 
    load on the machine  : Quite normal 
    innodb_log_file_size  : 1MB 
    innodb_buffer_pool_size : 8MB 
    innodb_thread_concurrency : 8 
    Query      : update wlists set customer_id = 1000 where id = 300; 

我試圖像OPTIMIZE TABLE不同的選項，增加了日誌緩衝區，檢查網絡延遲，但沒有一個人工作。我會非常感謝那些願意幫助我的人。

這裏是表的DESC和EXPLAIN。

mysql> DESC wlists ; 
    +-------------+--------------+------+-----+---------+----------------+ 
    | Field  | Type   | Null | Key | Default | Extra   | 
    +-------------+--------------+------+-----+---------+----------------+ 
    | id   | int(11)  | NO | PRI | NULL | auto_increment | 
    | customer_id | int(11)  | NO | MUL | NULL |    | 
    | name  | varchar(45) | YES |  | NULL |    | 
    | created  | datetime  | YES |  | NULL |    | 
    | modified | varchar(255) | YES |  | NULL |    | 
    +-------------+--------------+------+-----+---------+----------------+ 
    5 rows in set (0.01 sec) 

    mysql> explain select customer_id from wlists where id = 300 ; 
    +----+-------------+-----------+-------+---------------+---------+---------+-------+------+ 
    | id | select_type | table  | type | possible_keys | key  | key_len | ref | rows | Extra | 
    ----+-------------+-----------+-------+---------------+---------+---------+-------+------+ 
    | 1 | SIMPLE  | wishlists | const | PRIMARY  | PRIMARY | 4  | const   | 1 |  | 
    +----+-------------+-----------+-------+---------------+---------+---------+-------+------+-------+ 
    1 row in set (0.00 sec) 

SELECT正在工作正常。問題僅在於UPDATE/INSERT。

問候， UDAY

Answer 1

的innodb_flush_log_at_trx_commit設置爲1，總會引起的寫入性能下降因爲InnoDB將等待操作系統每次操作後磁盤成功返回。儘管如此，請注意操作系統有時會基於自己的緩存而存在。

但是設置innodb_flush_log_at_trx_commit == 1也是保證ACID和完整數據恢復（假設操作系統不會太多）的唯一方法。所以這是一個折衷。處理這個問題的理想方法是使用具有自己的寫緩存的電池備份存儲系統。這樣，您就可以獲得寫入緩存的優勢，而不會出現數據恢復問題。當然，您必須確保電池備份完全維持，並且在電池經過定期維護週期時您將遇到寫入速度問題。