• Lock contention in MySQL


    Lock is a mechanism for computer to coordinate multiple processes or threads to access a resource concurrently!No matter MyISAM or InnoDB, lock contention will occur. In theAll kinds of locks in MySQLIn this article, we have talked about how to view table lock and row lock contention ======================================================================= 1. Table locking SHOW STATUS LIKE ‘table%’; […]

  • Universal webassembly runtime — wasmer 1.0 GA


    Wasmer was the first to run on the server sideNginxWeb assembly (wasm) runtime of. Using wasm for software containerization, we create a general binary file, which can run anywhere without modification, including Linux, MacOS, windows, web browser and other operating systems. By default, wasm automatically sandboxes applications for safe execution, thus protecting the host environment […]

  • Angular2 Dependency Injection


    preface Dependency injection is one of the core concepts of angular. Through dependency injection, we can hand over complex and tedious object management to angular, and focus our work on business better.Dependency injection itself is the concept of back-end coding, which should be familiar to those who are familiar with spring framework. Angular1 introduced dependency […]

  • MySQL optimization I (Introduction to literacy and indexing) (Advanced chapter)


    Previously, we learned about the locks of MyISAM and inoodb engines. Now let’s talk about the differences between the two engines. What are they suitable for? What MyISAM engine is suitable for:(it doesn’t support transactions or foreign keys, especially for fast access speed, no requirement for transaction integrity, or application based on select and insert […]

  • Mybatis [2.3] – must mybatis use commit to successfully modify data?


    The code is placed directly in GitHub warehouse【 https://github.com/Damaer/Myb… 】Mybatis-02 can be run directly, so it doesn’t take up space. Why do we sometimes modify the database successfully without using commit? [TOC] 1. From the database level, in fact, it mainly depends on what “storage engine” you use For example, the following code uses the […]

  • Research on hybrid development framework of flutter boost


    1、 Introduction to flutter boost As we all know, flutter is a cross platform technical framework composed of flutter engine implemented by C + + and framework implemented by dart. Among them, the flutter engine is responsible for thread management, dart VM state management and dart code loading, while the framework implemented by dart code […]

  • MySQL unique index


    Unique index of MySQL(unique index)It’s easy to understand that the value of this index is unique. There are not many documents and concepts related to unique index. Just remember the core concept of “unique” This is mysqlUnique IndexesThe official text of Unique Indexes A UNIQUE index creates a constraint such that all values in the […]

  • Apache Flink in the past, present and future of Kwai Fu


    This article is shared by Zhao Jianbo, the head of Kwai Kwai big data architecture team, which mainly introduces the past, present and future of Apache Flink. The contents include: Why Flink Flink’s development in Kwai Fu Business data flow technological innovation Future plans 1、 Why Flink Hello, everyone. I am Zhao Jianbo, from Kwai […]

  • Real time computing framework: Spark cluster construction and introduction case


    1、 Spark overview 1. Introduction to spark Spark is designed for large-scale data processing. It is a fast, universal and scalable cluster computing engine based on memory. It implements an efficient DAG execution engine. It can process data streams efficiently based on memory. Compared with MapReduce, the computing speed has been significantly improved. 2. Operation […]

  • MySQL query statement execution process


    MySQL query statement execution process   MySQL is divided intoServer layerandStorage engineTwo parts, maybe one more layeradjoining course   Connection layer MySQL uses a typical C / S architecture. The connector completes the connection through a typical TCP handshake. It should be noted that, If the user name and password are correct, then the permissions […]

  • MySQL storage engine and application scenarios


    1 Isam It is fast in reading data, and does not occupy a lot of memory and storage resourcesHowever, transaction, foreign key and index are not supported.MySQL ≥ 5.1 is no longer supported. 2 Berkeley Transaction features such as commit and rollback are supported. MySQL is no longer supported in versions ≥ 5.1. 3 CSV […]

  • Springboot quick start Chapter 9 web application development


    1 Application Development Foundation 1.1 static files 1: Spring boot provides us with static resource processing by default. Webmvcautoconfiguration is used to configure various properties. It is recommended to use the default configuration method. The static resource mapping provided is as follows according to the priority order: classpath:/META-INF/resources classpath:/resources classpath:/static classpath:/public 2: It can be […]