the largest value you actually can transmit between the client and server is determined by the amount of available memory and the size of the communications buffers. https://dev.mysql.com/doc/refman/8.0/en/blob.html…

MySQL中的Blob类型 MySQL中存放大对象的时候,使用的是Blob类型.所谓的大对象指的就是图片,比如jpg.png.gif等格式的图片,文档,比如pdf.doc等,以及其他的文件.为了在数据库中存放这些文件,数据库软件中一般都支持blob类型,用来把这些文档的二进制数据存入其中. 目录 1.大对象介绍 2.MySQL中如何存储大对象 3.MySQL中Blob类型的使用,创建blob类型的字段,插入blob数据,查询blob数据 1.大对象介绍 =============== 参考资料:…

一.概述 1.SACK下的特殊处理过程 SACK下的拥塞控制处理是linux中拥塞控制的实现依据,再次强调一遍RFC6675的重要性,linux中拥塞控制主体框架的实现是与RFC6675一致的,所以如果要理解linux中拥塞控制的实现,强烈建议看一下RFC6675.我这里给出RFC6675中SACK处理的2个关键点,下面的描述实际上不太严谨,严谨定义请参考RFC6675. 1.SACK下对于dup ACK的定义简单说是指反馈了新的SACK信息,也就是说SACK下ack number不同的ACK报…

Given an integer array, find the top k largest numbers in it.   Example Given [3,10,1000,-99,4,100] and k = 3. Return [1000, 100, 10]. 解法一: class Solution { public: /* * @param nums: an integer array * @param k: An integer * @return: the top k larges…

RAC: Frequently Asked Questions [ID 220970.1]   修改时间 13-JAN-2011     类型 FAQ     状态 PUBLISHED   Applies to: Oracle Server - Enterprise Edition - Version: 9.2.0.1 to 11.2.0.1 - Release: 9.2 to 11.2 Purpose Frequently Asked Questions for Real Applicatio…

RFID读写器的工作原理 RFID的数据采集以读写器为主导,RFID读写器是一种通过无线通信,实现对标签识别和内存数据的读出和写入操作的装置. 读写器又称为阅读器或读头(Reader).查询器(Interrogator).读出装置(Reading Device). 扫描器(Scanner).通信器(Communicator).编程/编码器(Programmer)等等. 读写器工作原理 RFID读写器的基本原理是利用射频信号与空间耦合传输特性,使电子标签与阅读器的耦合元件在射频耦合通道内进行能量传…

This 125 kHz RFID reader http://www.serasidis.gr/circuits/RFID_reader/125kHz_RFID_reader.htm http://www.serasidis.gr/circuits/RFID_reader/images/125kHz_RFID_reader_schem.GIF I will try to explain with simple words how the RFID works. The ATtiny13 use…

Network Working Group R. Fielding Request for Comments: 2616 UC Irvine Obsoletes: 2068 J. Gettys Category: Standards Track Compaq/W3C J. Mogul Compaq H. Frystyk W3C/MIT L. Masinter Xerox P. Leach Microsoft T. Berners-Lee W3C/MIT June 1999 Hypertext T…

https://msdn.microsoft.com/en-us/library/ff647787.aspx Retired Content This content is outdated and is no longer being maintained. It is provided as a courtesy for individuals who are still using these technologies. This page may contain URLs that we…

原文链接:https://openmaniak.com/iperf.php Iperf is a tool to measure the bandwidth and the quality of a network link. Jperf can be associated with Iperf to provide a graphical frontend written in Java. The network link is delimited by two hosts running I…

Copied From:https://computing.llnl.gov/tutorials/parallel_comp/ Author: Blaise Barney, Lawrence Livermore National Laboratory UCRL-MI-133316 Table of Contents Abstract Overview What is Parallel Computing? Why Use Parallel Computing? Who is Using Para…

part of Hypertext Transfer Protocol -- HTTP/1.1RFC 2616 Fielding, et al. 14 Header Field Definitions(规定) This section(部分,章节) defines(规定定义) the syntax(语法) and semantics(语意) of all standard(标准) HTTP/1.1 header fields. For entity-header fields, both sen…

Introduction Computer Network: hosts, routers, communication channels Hosts run applications Routers forward information Packets: sequence of bytes contain control information e.g. destination host Protocolis an agreement: meaning of packets structur…

原文网址:http://blog.csdn.net/longxibendi/article/details/6048231 1.网址: http://www.mjmwired.net 2.比如查看这个 proc.txt ,就在这里能找到. http://www.mjmwired.net/kernel/Documentation/filesystems/proc.txt 内核参数解释全在这里了.不过,也可以下载内核完源代码,从/usr/src/linux/Documentation/proc.tx…

Linux TCP Performance Tuning News Linux Performance Tuning Recommended Books Recommended Links Linux performance bottlenecks Kernel parameters tuning on Linux Performance Monitoring tcpdump iptraf netstat ntop nfsstat lsof vmstat Disk subsystem tunin…

SNMP OID Reference - NetScaler 10 https://docs.citrix.com/content/dam/docs/en-us/netscaler/10/downloads/ctx132381.htm System Limits for a NetScaler Appliance 参考 https://support.citrix.com/content/dam/supportWS/kA460000000CcAzCAK/CTX118716.pdf This re…

转自:https://www.linuxtv.org/downloads/legacy/video4linux/API/V4L2_API/spec-single/v4l2.html Video for Linux Two API Specification Revision 2.6.32 Michael H Schimek <mschimek@gmx.at> Bill Dirks Original author of the V4L2 API and documentation. Hans V…

转自:http://blog.csdn.net/jmq_0000/article/details/7536805#t136 Video for Linux Two API Specification Revision 0.24 Michael H Schimek <mschimek@gmx.at> Bill Dirks Hans Verkuil Martin Rubli Copyright © 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 20…

1 https://zh.wikipedia.org/wiki/HTTP/2 HTTP/2 维基百科,自由的百科全书                         HTTP/2(超文本传输协议第2版,最初命名为HTTP 2.0),是HTTP协议的的第二个主要版本,使用于万维网.HTTP/2是HTTP协议自1999年HTTP 1.1发布后的首个更新,主要基于SPDY协议.它由互联网工程任务组(IETF)的Hypertext Transfer Protocol Bis(httpbis)工作小组进行…

NOTE: This specific issue was fixed before the launch of Privacy-Preserving Contact Tracing in iOS 13.5 in May 2020. In this demo I remotely trigger an unauthenticated kernel memory corruption vulnerability which causes all iOS devices in radio-proxi…

内容概述 本文内容来自开发文档"Traning > Displaying Bitmaps Efficiently",包括大尺寸Bitmap的高效加载,图片的异步加载和数据缓存. Bitmap的处理和加载非常重要,这关系到app的流畅运行和内存占用,如果方法不当,很容易导致界面卡顿和OOM.其中的原因大致有: android系统对进程的内存分配限制,移动设备的配置较低. Bitmap会消耗很大内存.比如相机拍下的 2592x1936 像素的照片,以ARGB_8888 格式一次加载到…

Awesome系列的Java资源整理.awesome-java 就是akullpp发起维护的Java资源列表,内容包括:构建工具.数据库.框架.模板.安全.代码分析.日志.第三方库.书籍.Java 站点等等. 经典的工具与库 (Ancients) In existence since the beginning of time and which will continue being used long after the hype has waned. Apache Ant - Build…

消息,就是指Windows发出的一个通知,告诉应用程序某个事情发生了.例如,单击鼠标.改变窗口尺寸.按下键盘上的一个键都会使Windows发送一个消息给应用程序.消息本身是作为一个记录传递给应用程序的,这个记录中包含了消息的类型以及其他信息.例如,对于单击鼠标所产生的消息来说,这个记录中包含了单击鼠标时的坐标.这个记录类型叫做TMsg, 它在Windows单元中是这样声明的:typeTMsg = packed recordhwnd: HWND; / /窗口句柄message: UINT; / /…

By now almost everyone has heard of so-called zero-copy functionality under Linux, but I often run into people who don't have a full understanding of the subject. Because of this, I decided to write a few articles that dig into the matter a bit deepe…

对Oracle数据库整体性能的优化,首先要关注的是在有性能问题时数据库排名前几位等待事件是哪些.Oracle等待事件众多,随着版本的升级,数量还在不断增加,可以通过v$event_name查到当前数据库版本包含的等待事件.例如我在Linux平台查11.2.0.4版本的Oracle是有1367个等待事件.SELECT name FROM V$EVENT_NAME ORDER BY name; 如此多的等待事件自然是要分类汇总,并对常见的等待事件有比较深入的认识,才能在Oracle数据库调优这条路上…

1.环境介绍 服务器硬件:Dell R710 服务器OS:红帽子Linux   RHEL4.8 数据库:Oracle 10g 2.出现的问题 因为数据表每天有上百万的数据写入表,加上建立索引,导致表空间不停增长,表空间被设置为自动增长,因此dbf文件在不断增大,硬盘空间在每天约400M的速度减少.数据库虽有自清理的脚本,清理3个月前的数据,但实际增加的数据太多,清理释放的空间不能满足需求了. 3.处理过程 解决思路是,该服务器的硬盘有预留空间,未完全划分的约有100G,可以建立新的分区,将已经存…

PORT Mode: 1. FTP client use TCP port 1026 for command to FTP server command port 212. FTP server use TCP port 21 responed  to FTP client command port 10263. FTP server use TCP port 20 for sending data to FTP client data port 1027 (1026 + 1)4. FTP cl…

问题导读1.borker包含哪些属性?2.Producer包含哪些属性?3.Consumer如何配置?borker(0.9.0及0.10.0)配置Kafka日志本身是由多个日志段组成(log segment).一个日志是一个FileMessageSet,它包含了日志数据以及OffsetIndex对象,该对象使用位移来读取日志数据 * borker配置就是指配置server.properties文件 *最小配置通常情况下需要在减压缩kafka后,修改config/server.properties…

常规方法 超时 class MedianFinder { vector<int> coll; public: MedianFinder(){ } void heapfu(vector<int>& coll,int idx,int max){ int left=2*idx+1,right=2*idx+2; int largest=idx; if(left<max&&coll[left]>coll[idx]) largest=left; if(rig…

#    WELCOME TO SQUID 3.0.STABLE26#    ----------------------------##    This is the default Squid configuration file. You may wish#    to look at the Squid home page (http://www.squid-cache.org/)#    for the FAQ and other documentation.##    The def…