a picture of innodb_adaptive_hash_index
来源:互联网 发布:网络调研报告的格式 编辑:程序博客网 时间:2024/06/05 17:36
在默认情况下,innodb_adaptive_hash_index都是被打开的,大家可以通过如下的方式查看:
root@(none) 11:32:56>show variables like '%adaptive%';
+----------------------------+-------+
| Variable_name | Value |
+----------------------------+-------+
| innodb_adaptive_hash_index | ON |
+----------------------------+-------+
+----------------------------+-------+
| Variable_name | Value |
+----------------------------+-------+
| innodb_adaptive_hash_index | ON |
+----------------------------+-------+
关于通过innodb adaptive hash index访问数据的体系结构如下:
我选择了两个mysql数据库系统,查看了innodb status中关于 ADAPTIVE HASH INDEX部份,得到的信息如下:
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 0, seg size 2,
0 inserts, 0 merged recs, 0 merges
Hash table size 42499631, used cells 30149, node heap has 46 buffer(s)
0.22 hash searches/s, 618.09 non-hash searches/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 0, seg size 2,
0 inserts, 0 merged recs, 0 merges
Hash table size 42499631, used cells 1644761, node heap has 2475 buffer(s)
21688.13 hash searches/s, 5885.36 non-hash searches/s
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 0, seg size 2,
0 inserts, 0 merged recs, 0 merges
Hash table size 42499631, used cells 30149, node heap has 46 buffer(s)
0.22 hash searches/s, 618.09 non-hash searches/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 0, seg size 2,
0 inserts, 0 merged recs, 0 merges
Hash table size 42499631, used cells 1644761, node heap has 2475 buffer(s)
21688.13 hash searches/s, 5885.36 non-hash searches/s
从上面的显示结果可以看出,第一个通过hash searching命中率的相当低;而第二个命中率比较高。出现如上的情况,跟这两个数据库所运行的业务系统有着直接的关系,大家的系统是否存在这样的情况呢?
--EOF--
Trackback:http://rdc.taobao.com/blog/dba/html/262_picture-of-innodb_adaptive_hash_index.html/trackback
- a picture of innodb_adaptive_hash_index
- a picture of innodb_adaptive_hash_index
- The BIG Picture : a Map of CVM
- The BIG Picture : a Map of CVM
- How to remove background of a picture?
- a picture
- innodb innodb_adaptive_hash_index
- the picture of edyliu
- take a picture
- reading the path of picture
- VMware architecture - a rough picture
- A picture from notepad++ site.
- Gym 100917 A. Abstract Picture
- Euler Angle in a picture
- Grab a picture from a FLV file
- Hide a file in a picture
- Hide a file in a picture
- Picture of an Angel 天使留踪
- 防止同一用户同时登陆
- Eclipse插件管理
- 专注在浮躁的时代
- Oracle RAC For Redhat Linux 4
- PB与各种数据库连接
- a picture of innodb_adaptive_hash_index
- 进程优先级和进程nice值?
- 文档测试介绍
- My.Mp3.2009[01]
- happy
- 请高手指点怎么写校内网开心农场游戏的外挂代码
- 04/28/09
- My.Mp3.2009[02]
- OSI与TCP IP模型一(图)