开启 Profiling
功能,对慢查询进行优化:mongodb可以通过profile来监控数据,进行优化。查看当前是否开启profile功能用命令db.getProfilingLevel()
返回level等级,值为0|1|2,分别代表意思:0代表关闭,1代表记录慢命令,2代表全部db.setPr...
分类:
数据库 时间:
2014-05-24 01:26:42
阅读次数:
352
InnoDBRecord, Gap, and Next-Key
Locks考虑到翻译准确性,对于某些特殊名称不做翻译,以免误导;InnoDBhas several types of record-level locks
including record locks, gap locks, and n...
分类:
数据库 时间:
2014-05-23 23:19:29
阅读次数:
683
解决办法:首选找到 build path - 然后选择 Configure build
path项选择 "Order and Export" 栏选中
"achartengine-1.0.0.jar“,然后让它置顶,点击"UP"更新你的项目(Project ->
Clean...)碰到包类似的错,也....
分类:
编程语言 时间:
2014-05-23 10:24:56
阅读次数:
311
表T_phone中字段:Id, Haoduan, Adress, Type,
Quhao1,ROW_NUMBER()是个开窗函数,它可以与聚合函数一起用,就算删除表中的列,排序也不会乱select *,ROW_NUMBER()
over(order by id) as 排序 from T_Phone...
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其他好文 时间:
2014-05-20 13:16:26
阅读次数:
260
Communication SystemTime Limit: 1000MSMemory Limit:
10000KTotal Submissions: 22445Accepted: 7977DescriptionWe have received an order
from Pizoor Comm....
分类:
其他好文 时间:
2014-05-20 07:37:17
阅读次数:
454
volatile:java关键字,意为易变的,不稳定的,标识修饰java同步字段,示例:java单利模式public
class ApplicationCache{ private Map attributeMap; // volatile so that JVM
out-of-order...
分类:
编程语言 时间:
2014-05-19 14:56:56
阅读次数:
334
本技术支持指南主要处理:ASCII, binary, and MAT
files.要得到MATLAB中可用来读写各种文件格式的完全函数列表,可以键入以下命令: help iofun MATLAB中有两种文件I/O程序:high
level and low level. High leve...
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其他好文 时间:
2014-05-19 14:01:25
阅读次数:
393
题目链接 You are given two linked lists representing
two non-negative numbers. The digits are stored in reverse order and each of
their nodes contain a si...
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其他好文 时间:
2014-05-19 13:53:32
阅读次数:
296
DescriptionIn order to get from one of the F (1
2 and 1 –> 6 –> 5 –> 21 – 4: 1 –> 2 –> 3 –> 4 and 1 –> 6
–> 5 –> 43 – 7: 3 –> 4 –> 7 and 3 –> 2 –> 5 ....
分类:
其他好文 时间:
2014-05-19 12:43:06
阅读次数:
200
You are given two linked lists representing two
non-negative numbers. The digits are stored in reverse order and each of their
nodes contain a single ...
分类:
其他好文 时间:
2014-05-19 12:05:23
阅读次数:
386