• Let MySQL record the execution process for us


    Let MySQL record the execution process for us   We can turn on profiling and let MySQL record the execution process of SQL statements for us   View the profiling parameter shell > select @@profiling; Make changes shell > set profiling = 1; Execution statement select * from employees limit 100; View the statement execution […]

  • Chrome developer tool — performance reference


    Link to the original text:https://developers.google.com…Related articles:https://github.com/hewq/blog/… Disable JavaScript Samples By default,MainSection will record the call stack of JavaScript in detail, using theDisable JavaScript SamplesYou can hide these calls. Like some custom function calls will be hidden. The figure below shows the comparison before and after hiding View main thread MainSection records the activity of the […]

  • Leetcode 746. Using the least cost to climb stairs Python implementation


    Title Requirements: Thinking: dynamic programming The minimum amount of physical strength required to go up the current staircase is the lower of the previous staircase and the two previous stairs plus the amount of physical strength required to go up the current staircase Maintain an array DP, which is used to save the physical strength […]

  • Building a blockchain with go — Part 6: transaction (2)


    A series of translated articles I have put on GitHub:blockchain-tutorialAny subsequent updates will be on GitHub and may not be synchronized here. If you want to run the code directly, you can also run it in the SRC directory from the tutorial repository on clone GitHubmakeThat’s fine. introduction At the beginning of this series, we […]

  • Building blockchain based on Java language (6) — Merkle tree


    The final content is subject to the original texthttps://wangwei.one/posts/630… introduction At the beginning of this series, we mentioned that blockchain is a distributed database. At that time, we decided to skip distributed and focus on data storage. So far, we have implemented almost all the components of the blockchain. In this article, we will cover […]

  • Profiler of react learning


    ability: measure how often to render a react application and the cost of rendering, in order to identify the slower parts of the application. Usage: can be used anywhere in the react tree to measure the overhead of rendering that part. Demo: render() { return ( <App> <Profiler id=”Navigation” onRender={callback}> <Navigation props={…props} /> </Profiler> <Main […]

  • 20. Nginx performance optimization


    AB performance test yum install httpd-tools ab -n 100 -c 100 #Concurrent quantity Concurrency Level: 100 #Time spent on the whole test Time taken for tests: 0.014 seconds #Number of completed requests Complete requests: 100 #Number of failed requests Failed requests: 0 #Number of write errors Write errors: 0 #Number of non-200 response codes […]

  • Which do you choose, NPM or yarn?


    By Charlie midtlyng Crazy technology house Original: https://javascript.christmas/ No reprinting without permission Every team has to make decisions in the development process. It usually involvesyarn,npmOr other tools for building and packaging JavaScript code. Some developers are eager to move in a certain direction, sometimes they spend a lot of time trying to make decisions that […]

  • Python Foundation (18): preliminary understanding module, re module


    1. Understanding module Common scenario: a module is a file containing Python definitions and declarations. The filename is the module name plus the suffix. Py. However, the modules loaded by import are divided into four general categories: 1. Code written in python (. Py file) 2. C or C + + extensions that have been […]