• Detailed explanation of nonvolatile flash


    Flash (flash or flash memory) was first introduced by Intel in 1988. It is a nonvolatile memory that can be quickly erased and programmed by electricity. Its speed is relative to EEPROM. Flash can be divided into nor flash and NAND flash from chip technology. Nor FlashNOR flash is characterized by on-chip execution (XIP), which allows […]

  • Why write key in the list component when react / Vue project, and what is its function?


    Key is the unique ID given to each vnode. You can rely on the key to get the corresponding vnode node in oldvnode more accurately and faster. More accurate Because it is not in place reuse with key, in the samenode function a.key = = = b.key comparison, in place reuse can be avoided. So […]

  • Row and column for hybrid workloads


    Bridging the Archipelago between Row-Stores and Column-Stores for Hybrid WorkloadsCarnegie Mellon University(2016) A middle layer, can mix OLTP / OLAP, row benefits: NSM (n-ary) read single row multiple attributes fast, DSM (decomposition) column benefits: better vectorization, suitable for reading less attributes, not suitable for single large insert, to split a row into different columns.Physically, different […]

  • Using memcached as cache in 2016 Django


    With memcached as cache, Django’s speed seems to fly up install sudo apt-get install memcached pip install python-memcached sudo apt-get install python-dev sudo apt-get install libmemcached-dev pip install pylibmc to configure CACHES = { ‘default’: { ‘BACKEND’: ‘django_pylibmc.memcached.PyLibMCCache’, ‘LOCATION’: ‘localhost:11211’, ‘TIMEOUT’: 500, ‘BINARY’: True, ‘OPTIONS’: { # Maps to pylibmc “behaviors” ‘tcp_nodelay’: True, ‘ketama’: True […]

  • Use canvas to simulate free fall movement to cool desktop background story


    1、 At the beginning of the story, I want a ball Objective: to make a free falling ball with canvas. The ball is elastic. Junior high school physics had gravity, remember the height,speedGravity, gravityaccelerationIf the ball is elastic, it will rebound. So use canvas to simulate an experimental scene, Build HTML template, initialize canvas and […]

  • Caching and buffering


    The idea of cache has a long history. In short, the purpose of cache is to save the calculation results which need to be expensive and take them out directly when they are needed in the future, so as to avoid repeated calculation. Computers and even the Internet, the application of cache is numerous, we […]

  • Accelerating GitHub cloning


    Background of the story During this period of time, GitHub’s clone was killing people. I was forced to watch several methods online Change hosts First pull to gitee, then clone from gitee Agency I used proxy. The second method is not suitable for me. Why? One is that I am lazy, and the other is […]

  • Large amount of data, paging query is very slow, how to optimize?


    When there are tens of thousands of records in the table to be queried from the database, all the results of one-time query will become very slow, especially with the increase of the amount of data. For database paging query, there are many methods and optimization points. Here are some of the ways I know. […]

  • A kind of Front end multi thread large file download practice, speed up 10 times, take advantage of Baidu cloud disk


    background Yes, you’re right. It’s front-end multithreading, notNode。 This exploration originated from the recent development. When we met the development requirements related to video stream, we found a special status code, his name is called206~ In order to prevent the boring of this paper, the first effect of the town text. (take a picture3.7MFor example, […]

  • Double the optimization of webpack to improve your construction efficiency


    Project construction analysis and specific methods 1. Project construction analysis tool 1. Speed analysis tool speed measure webpack plugin, you can see the time consumption of each loader and plug-in2. Webpack bundle analyzer, the size of the packaged file can be seenThrough the analysis tool, we can know exactly where the bottleneck of our construction […]

  • Using cache to improve the speed of secondary construction in webpack


    1. Babel loader enables caching Description in official documents: https://webpack.docschina.org…Cachedirectory: the default value is false. When there are settings, the specified directory will be used to cache the execution results of the loader. After the webpack build, it will try to read the cache to avoid the Babel recompilation process which may cause high performance […]

  • How to set up agent for Git


    Today, we found that git was very slow when pulling projects.Obviously, I have already set up SS. In the past, the speed was still OK. Today, I found that it was only ten kilos.This paper studies the method of GIT setting proxy. First of all, make sure that you have opened an agent locally. My […]