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  Why MySQL 8 drops support of query cache

Many of you may have heard or used MySQL's query cache, because it used to be a popular way to improve MySQL's performance. As an important feature for improving MySQL's performance, the query cache was often recommended as a solution for slow queries. However, why has MySQL 8 abandoned the query cache? Today, we will analyze and explore this decision. What is query cache? According to official document: The query cache stores the text of a SELECT statement together with the correspon...

   MYSQL 8,QUERY CACHE     2023-03-11 09:05:17

  Should All Web Traffic Be Encrypted?

The prevalence of free, open WiFi has made it rather easy for a WiFi eavesdropper to steal your identity cookie for the websites you visit while you're connected to that WiFi access point. This is something I talked about in Breaking the Web's Cookie Jar. It's difficult to fix without making major changes to the web's infrastructure. In the year since I wrote that, a number of major websites have "solved" the WiFi eavesdropping problem by either making encrypted HTTPS web traffic an accou...

   Web traffic,Security,HTTPS.Encryption,Wifi     2012-02-24 05:02:58

  Find max subarray of an array

In computer science, the maximum subarray problem is the task of finding the contiguous subarray within a one-dimensional array of numbers (containing at least one positive number) which has the largest sum. For example, for the sequence of values −2, 1, −3, 4, −1, 2, 1, −5, 4; the contiguous subarray with the largest sum is 4, −1, 2, 1, with sum 6. The problem was first posed by Ulf Grenander of Brown University in 1977,...

   Max Subarray, Divide and conquer,Kadane     2013-04-22 11:50:35

  Bytes Matter

I love to profile applications, because I always learn something that surprises me. Initial Profiler Surprise: Client Side Case in point, I was recently profiling our Android application, the Famigo Sandbox. This app sends a lot of data back and forth with our API, as we try to determine which of the apps on your phone are safe for your kids. I always assumed that, if app performance suffered during some of the ...

   Byte,Low level,Operation,Importance     2012-02-28 08:07:22

  Speed Hashing

A given hash uniquely represents a file, or any arbitrary collection of data. At least in theory. This is a 128-bit MD5 hash you're looking at above, so it can represent at most 2128 unique items, or 340 trillion trillion trillion. In reality the usable space is substantially less; you can start seeing significant collisions once you've filled half the space, but half of an impossibly large number is still impossibly large. Back in 2005, I wondered about the difference between a checksum and...

   Speed hashing,Security,MD5     2012-04-07 10:35:15

  20 Database Design Best Practices

Use well defined and consistent names for tables and columns (e.g. School, StudentCourse, CourseID ...).Use singular for table names (i.e. use StudentCourse instead of StudentCourses). Table represents a collection of entities, there is no need for plural names.Don’t use spaces for table names. Otherwise you will have to use ‘{‘, ‘[‘, ‘“’ etc. characters to define tables (i.e. for accesing table Student Course you'll write “Student Cour...

   Database design,20 tips,Well defined name,Design pattern     2012-02-07 12:10:48

  Where do software engineers get highest pay?

According to Tencent Tech, Tech companies are generous to engineers is not a secret because there is a lack of excellent engineers. These companies are willing to pay high salary and provide attractive welfare to attract these talented people. Recently, a list of companies which pay highest average salary to software engineers is published. The interesting thing is Apple, Google or Facebook is not the company which pays highest. Then which one? The answer is Juniper. The average salary in Junipe...

   Software engineer,Salary,Juniper     2013-04-12 21:06:52

  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

  Linux的早期岁月

我的名字是 Lars Wirzenius，我曾经见证了Linux的起点。Linux现在是一个全球成功的操作系统，但它的开始却非常谦逊。这些是我对Linux最早的日子、它的创造以及它走向今天的记忆。 我于1988年秋季开始在赫尔辛基大学攻读计算机科学，并认识了 Linus Torvalds，他也是当年计算机科学专业的新生之一，而且和我一样说瑞典语。在那个学年的末尾，我们得到了一台Unix服务器的访问权限...

   LINUX,HISTORY,STORY     2023-05-18 07:23:18

  10 stupid things smartphone users usually do

What are the things you like doing with your smartphones? Making phone calls? Playing games? Taking photos? Today we will not discuss what we should do with our smartphones, instead we will summarize 10 stupid things smartphone users usually do. 1. Taking photos of food and share them Please. The only time people want to stare at food is when we see the menu before ordering. 2. Sending SMS to solve dispute You will miss the two key components in communication : content and tone. 3. Holding mobil...

   Smartphone,Stupid     2013-05-28 12:49:05

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