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TokuMX vs. MongoDB 性能对比 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
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磁盘消耗对比:
选择MongoDB就必然会面对磁盘消耗的问题。我们拿到的数据大概是这样的:每天的数据量不到200万条,平均数据的大小不超过4k,但MongoDB存一个月的数据就需要接近40G,最近三个月的数据则需要接近100G。限...
闲扯Nginx的accept_mutex配置 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...新连接,其它的Worker会重新进入休眠状态,这就是「惊群问题」。
Nginx缺省激活了accept_mutex,也就是说不会有惊群问题,但真的有那么严重么?实际上Nginx作者Igor Sysoev曾经给过相关的解释:
OS may wake all processes waiting on accept(...
MySQL ('root'@'%') does not exist 的问题 - 爬虫/数据库 - 清泛IT社区,为创新赋能!
MySQL ('root'@'%') does not exist的问题:
在使用mysql时出现问题: The user specified as a definer ('root'@'%') does not exist。
一般是由于root用户对全局host无访问权限。因此只要给root用户添加一个访问权限即可。
解决办法:
登陆mysql ,...
大数据不是万能的 - 资讯 - 清泛网 - 专注C/C++及内核技术
...地方。我们认为,大数据其实面对的不是99%的机构面对的问题,这个说法跟市场上很多的说法不大一样。
我们看一下,把这个额度分配到一万到十万区域。在这个领域从事信贷服务的,大家马上想到的是信用卡,也可能想到某...
PHP json_decode() returns NULL with valid JSON?
...ters since I started the application and there were no problems before. Locally, the JSON decoding works perfectly. On my server, it doesn't. And I can't call json_last_error() because it's PHP 5.2.9. That function appears on PHP 5.3.0.
– Joel A. Villarreal Bertoldi
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一文讲透区块链技术原理 - 资讯 - 清泛网 - 专注C/C++及内核技术
...定是可信的。
区块链技术原理的来源可归纳为一个数学问题:拜占庭将军问题。拜占庭将军问题延伸到互联网生活中来,其内涵可概括为:在互联网大背景下,当需要与不熟悉的对手方进行价值交换活动时,人们如何才能防止...
How to convert all tables from MyISAM into InnoDB?
I know I can issue an alter table individually to change the table storage from MyISAM to InnoDB.
26 Answers
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How do I make a request using HTTP basic authentication with PHP curl?
I'm building a REST web service client in PHP and at the moment I'm using curl to make requests to the service.
11 Answers
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How to apply bindValue method in LIMIT clause?
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@Ross I cannot specifically answer this- but I can point out that LIMIT and OFFSET are features that were glued on AFTER all this PHP/MYSQL/PDO madness hit the dev circuit... In fact, I believe it was Lerdorf himself who oversaw LIMIT implementatio...
coinitialize失败,返回值是0x80010106 无法在设置线程模式后对其加以更改 ...
...ze()不当所致。遂改用
CoInitializeEx(NULL, COINIT_MULTITHREADED);
问题得以解决。
CoInitialize、CoInitializeEx都是windows的API,主要是告诉windows以什么方式为程序创建COM对象,原因是程序调用com库函数(除CoGetMalloc和内存分配函数)之前...
