我注意到我的服务器消耗了将近500 MB的RAM,启动了19个线程,如下图所示。
MYSQL线程顶部图像:
📷
以下是配置:
-------- General Statistics --------------------------------------------------
[--] Skipped version check for MySQLTuner script
[OK] Currently running supported MySQL version 5.1.41-3ubuntu12
[OK] Operating on 32-bit architecture with le
mysql> explain SELECT *
-> FROM (`items`)
-> WHERE `states` = 'A'
-> ORDER BY `updated_date` desc
-> LIMIT 20520, 40;
+----+-------------+--------+--------+----------------------------+---------------------+---------+----------+-------+-------------+
| id | sel
我要计算指数命中率。
“索引命中率”是指我做了多少选择查询命中索引。我在谷歌搜索过。但它不支持mysql。
我认为我可以使用二进制日志来计算索引命中率。但我不知道怎么实现
SELECT * FROM USER WHERE ID = 1 (Comes From server 1)
SELECT * FROM USER WHERE ID = 2 (Comes From server 2)
SELECT * FROM USER WHERE ID = 3 (Comes From server 1)
我有一个用于Mysql的虚拟化32位服务器(RAM : 115 Go)。
我正在尝试优化mysqltuner,我得到了以下内容:
>> MySQLTuner 1.1.1 - Major Hayden <major@mhtx.net>
>> Bug reports, feature requests, and downloads at http://mysqltuner.com/
>> Run with '--help' for additional options and output filtering
Please
我正在开发一个网站,其中每种类型的用户({guest,loggedIn})可以查看N个页面,在不同的文化({en-US...})。我使用GetVaryByCustomString来处理每个页面的缓存:
Public Overrides Function GetVaryByCustomString(ByVal currentContext As HTTPContext, ByVal customArgs As String) As String
Select Case customArgs
Case "userAndCulture"
在使用以下方法之一时是否存在性能问题?哪个更快(如果有的话)?如果有任何性能测试,那就太好了。
多维阵列:
// Using multidimmentional array:
int ****multidim_arr;
// ... initialization, etc. ...
int val = multidim_arr[a][b][c][d];
平面阵列:
// Using flat array (or single array)
int *flat_arr;
// ... initialization, etc. ...
int val2 = flat_arr[a * a_lvl +