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  Data type in MySQL

For both small free database space and large e-commerce websites, reasonable database table structure design is essential. To achieve this, it requires us to have a full understanding of commonly used data types in database system. Below we share some knowledge about data types in MySQL.1. Numeric typesThe numeric types can be classified as : integer, float and decimal type.The so-called "decimal" refers DECIMAL and NUMERIC, they are of the same type. Strictly speaking it is not a numeric type, ...

   MySQL, Data type,VARCHAR     2013-01-01 10:56:06

  A Python assignment trap

Python has no assignment, it only has reference. Assume, we have following code snippet: >>> values = [0, 1, 2] >>> values[1] = values >>> values [0, [...], 2] Why the result is not [0, [0, 1, 2], 2], instead it goes into an infinite loop? To understand this, we need to understand some basics about Python. Python has no variables, it only has labels. When we run: values = [0, 1, 2] Python will first create a list object [0,1,2], then it labels it as values. If we later...

   Python,Assignment,Trap,Shallow copy     2013-07-19 22:08:36

  A journey to investigate a goroutine leakage case

In Go, creating goroutines is straightforward, but improper usage may result in a large number of goroutines unable to terminate, leading to resource leakage and memory leaks over time. The key to avoiding goroutine leaks is to manage the lifecycle of goroutines properly. By exporting runtime metrics and utilizing pprof, one can detect and resolve goroutine leakage issues. This post will go through one real case encountered by the author. The author maintains a service that connects to a targe...

   TIMEOUT,SSH,GUIDE,DEBUG,LEAK,GOROUTINE,PPROF,GOLANG     2024-03-16 11:00:23

  Amazon unveils 8.9" Kindle Fire HD

Amazon today unveiled 7 products of Kindle family, including the $69 new Kindle; Kindle Paperwhite WiFi/3G, priced at $119 / $179; 7-inch Kindle Fire regular edition/HD version, $159/$ 199; 8.9inch Kindle Fire HD with WiFi/4G Edition at $299 /$499. However, the Amazon phone did not show up. The 8.9-inch Kindle Fire HD is today's highlight, because it looks real similar to iPad. Kindle Fire HD has the following features: 1920 x 1200 resolution, 254PPI Texas Instruments OMAP 4470 proce...

   Amazon,Kindle Fire HD,tablet     2012-09-06 19:12:05

  this in JavaScript in detail

this in JavaScript is always confusing, it is one of the most frequently seen traps in JavaScript. this is not a good design in JavaScript(You can refer some other design flaws of JavaScript here), since it's lazy binding feature, it can be a global object, the current object or.... Some people even avoid using this in JavaScript. Actually if you master how this works, then you will know how to stay away from these traps. Let's take a look at what this points to in below situations. 1. In global...

   JavaScript,this,bind     2013-05-09 18:35:12

  Why is Golang's Compilation Speed So Fast?

Overview When I started learning the Go language, I already had experience with three statically typed languages—C/C++ and Java—and two dynamically typed languages—PHP and JavaScript. Because of this background, when I compiled a demo file of several hundred lines for the first time in Go, I was genuinely impressed by its compilation speed. At that moment, I thought to myself, "Go claims to have the execution speed of statically typed languages and the compilation speed of dyna...

   GOLANG,COMPILATION,GO     2024-10-07 22:02:23

  Stub Mixlib::ShellOut and shell_out in Ruby unit testing

Unit testing is part of software development to ensure the tiny component of a function can work as designed. Different frameworks and tools can be used to run unit testing for different programming languages. In Ruby, one popular unit testing framework is Rspec, or Chefspec if you are writing Chef recipes. While writing Chef recipes, some low level commands(DOS commands or shell commands) need to be executed on the managed resource to perform actions or gather information. For example, lis...

   RUBY,UNIT TESTING,RSPEC,CHEFSPEC,SHELL_OUT     2016-11-11 00:14:46

  Coming back, Nokia?

Nokia officially unveiled an Windows Phone 8 phone model Lumia 920T in cooperation with China Mobile in yesterday's Global Developer Conference of China Mobile. This is the first to support China Mobile's TD-SCDMA 3G mobile phone network standard in the Windows Phone ecosystem, it that Windows Phone is available in TD camp. Meanwhile, as China Mobile's official custom models, Lumia 920T will be sold using China Mobile's sales channel, this may further promote the sales of Nokia Windows Phone dev...

   Nokia, China Mobile, Lumia 920T,TD-SCDMA     2012-12-06 13:17:24

  Mount DD image on Linux

Yesterday, my Raspberry Pi running Arch Linux was not able to boot with error: Kernel Panic, not syncing: no init found. I spent a night on it, but could not find a working solution. The last option is easy: reinstall the system. That is really the last resort, for I do not want to re-setup everything I have done: samba server, Time Machine server, Xunlei Offline Downloader… Unable to mount the SD card The system does not boot, so I need to find a way to get into the file system to identi...

   LINUX,DD IMAGE     2014-06-24 07:49:14

  Samsung announces Galaxy Note II

Samsung announced Galaxy Note II in today's Mobile Unpacked conference. It has been one year since the first generation of Galaxy Note released in October last year.Galaxy Note â…¡ is not lighter, but a little thinner compared to Galaxy Note I. It is equipped with Android 4.1 Jelly Bean with a 5.5-inch screen. Detailed parameters are as follows: 1.6GHz quad-core Exynos processor 5.5 inches HD Super AMOLED screen, 1280 x 720 (16:9) 8 megapixel rear camera, 1.9 megapixel front camera 2G RAM,...

   Samsung,Galaxy Note II,Parameters,Price     2012-08-29 20:01:08

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