SEARCH KEYWORD -- TECHNOLOGY

  MySQL Index Merge Optimization Practices

In production environment databases, it is often seen that some SQL where conditions include: equal condition on a normal index + primary key range query + order by limit Although using a normal index would be more efficient, the system chooses to use index merge instead in some cases. This article explores such index merge situations. Index Merge Official Introduction   The Index Merge access method retrieves rows with multiple range scans and merges their results into one. Generall...

   INDEX MERGE,MYSQL,PRIMARY INDEX,SECONDARY INDEX     2024-09-10 04:52:26

  Learning Server-Side JavaScript with Node.js

Node.js is all the buzz at the moment, and makes creating high performance, real-time web applications easy. It allows JavaScript to be used end to end, both on the server and on the client. This tutorial will walk you through the installation of Node and your first “Hello World” program, to building a scalable streaming Twitter server.What is Node.js?JavaScript has traditionally only run in the web browser, but recently there has been considerable interest in bringing it to the...

   JavaScript,Server side,Node.js.Implement     2011-09-20 13:33:15

  Stuff The Internet Says On Scalability For September 16, 2011

Between love and madness lies HighScalability:Google now 10x better: MapReduce sorts 1 petabyte of data using 8000 computers in 33 minutes; 1 Billion on Social Networks;Tumblr at 10 Billion Posts; Twitter at 100 Million Users; Testing at Google Scale: 1800 builds, 120 million test suites, 60 million tests run daily.From the Dash Memo on Google's Plan: Go is a very promising systems-programming language in the vein of C++. We fully hope and expect that Go become...

   Scalability,Go,Google,MapReduce,Muppet,M     2011-09-20 11:22:36

  Understand GoLang WaitGroup internals and how it works

Background Before getting into the main content, let me give a brief introduction to WaitGroup and its related background knowledge. Here, the focus is on the basic usage of WaitGroup and the fundamental knowledge of system semaphores. For those who are familiar with these, you can skip this section directly. WaitGroup WaitGroup is one of the most common concurrency control techniques in Golang, and its function can be roughly compared to the join() in concurrency control of other languages' mul...

   GOLANG,WAITGROUP,SOURCE CODE     2023-04-26 08:02:01

  Python and PLC Communication

This article provides detailed steps on how to use Python to communicate with Schneider M221 and Siemens S7-1200 PLCs via Ethernet. Additionally, we offer a packaged Python PLC client library, enabling you to easily build your own SCADA control programs, such as Human-Machine Interfaces (HMI). The system overview is shown below: To check the project detail please refer to Python Physical PLC Communication Clients # Created: 2024/06/29 # Version: v0.1.3 # Copyright: Copyright (c) 2024 ...

       2024-06-30 02:21:17

  Be Aware of these 10 mistakes while designing Your Mobile App!

So you have finally decided to enter the world of technology and you are going to design an application for your business. The time has become when you have to give all the nitty-gitty grins a look and design your own mobile app for promoting your business online. Well when you have finally decided to design your mobile application, here are some mistakes that you are not allowed to make. Have a look:   Do Not Start Designing Your App Without Wireframes Normal 0 false ...

       2014-12-11 02:12:02

  Top 10 Reasons to Use HTML5 Right Now

So you’re still not using HTML5, huh? I guess you probably have your reasons; it’s not fully adopted yet, it doesn’t work in IE, you don’t like users, you’re out of touch or you are just passionately in love with writing strict XHTML code. HTML5 is the revolution that the web needed and the fact is, it is the future whether you like it or not — suck it up and deal. HTML5 isn’t hard to use or understand and even though it’s not fully a...

   HTML5,Accessibility,Cross browser compatibility     2011-12-08 02:52:38

  Scala feels like EJB 2, and other thoughts

At Devoxx last week I used the phrase "Scala feels like EJB 2 to me". What was on my mind?ScalaFor a number of years on this blog I've been mentioning a desire to write a post about Scala. Writing such a post is not easy, because anyone who has been paying attention to anti-Scala blog posts will know that writing one is a sure fire way of getting flamed. The Scala community is not tolerant of dissent.But ultimately, I felt that it was important for me to speak out and express my opinions. As I s...

   Scala,Module,EJB,Concurrency,Feature     2011-11-22 08:29:44

  The Death Of The Spec

Earlier today, my colleague Matt Burns wrote a post noting that most tablet makers may be largely failing because they’ve sold their soul to Android and are now just in the middle of a spec war, which no one can win. I’m gonna go one step further in that line of thinking: the spec is dead.There have been a few key stories from the past couple of weeks that highlight this new reality. Barnes & Noble unveiled the new Nook Tablet. Consumer Reports looked at the...

   Specification,Android,Platform,Software design     2011-11-15 08:20:22

  SQL Injection through HTTP Headers

During vulnerability assessment or penetration testing, identifying the input vectors of the target application is a primordial step. Sometimes, when dealing with Web application testing, verification routines related to SQL injection flaws discovery are restricted to the GET and POST variables as the unique inputs vectors ever. What about other HTTP header parameters? Aren’t they potential input vectors for SQL injection attacks? How can one test all these HTTP parameters and whic...

   Code security,SQL injection,HTTP header     2012-04-05 11:42:04

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