• Summary of Oracle common views


    1. Dynamic performance view of database / instancev$database :displays information about the database from the control file.V $instance: displays the state of the current instanceV $option: displays Oracle database options and features        Option must be separately licensed        whereas features come with the product and are enabled based on         The product that is runningv$parameter :displays information […]

  • Merge sort and cardinal sort


    Merge sort example Recursive sorting by iteration performance analysis Cardinal sort Multi keyword sorting Chain radix sort Comparison of various sorting methods

  • Springboot annotation Description:


    Basic annotation in springboot @Spring bootapplication annotation Any project has an entry. In the springboot boot boot class, you need to have @ springbootapplication annotation for contempt, and define a main method in the class. The main method will read the configuration file, load the specified resources, and then initializeTherefore: when the spring boot project […]

  • Less nesting rule


    describeIt is a set of CSS properties that allow the properties of one class to be used for another class and contain the class name as its property. In less, you can use class or ID selectors to declare mixins in the same way as CSS styles. It can store multiple values and can be […]

  • Practice of spa routing Trilogy


    review Core principles of spa routing TrilogyBefore we begin, let’s review what we learned in the previous article: there are two popular modes of front-end Routing: hash mode and history mode, which use the browser’s own characteristics to achieve single page navigation. Hash mode: window. Location or a label changes the anchor value, and window. […]

  • Elasticsearch series – production cluster deployment (Part 2)


    outline This article continues to explain the details of elasticsearch cluster deployment Cluster restart problem If our elasticsearch cluster does some off-line maintenance operations, such as expanding the disk and upgrading the version, it needs to start the cluster. When there are a large number of nodes, it may take a long time to start […]

  • How to write efficient controller in asp.net core


    By following best practices, you can write better controllers. So called “thin” controllers (controllers with less code and less responsibilities) are easier to read and maintain. And once your controllers are thin, you may not need to test them too much. Instead, you can focus on testing business logic and data access code. Another advantage […]

  • Introduction to Objective-C


    1、 Introduction to Objective-C Objective-objective-c is a strict superset of C language any C language program can directly pass through the Objective-C compiler without modification, and it is completely legal to use C language code in Objective-C. Objective-C is described as a thin layer over C language, because the original intention of Objective-C is to […]

  • Build sonarqube code quality detection platform based on docker composition


    1、 Demand In the process of our development, it is inevitable that sometimes the code is not standardized, or there are some static bug problems. At this time, a good code checking tool is very necessary, andsonarqubeIt just meets the whole requirement. 2、 The compilation of docker compose file version: “3” services: sonarqube: image: sonarqube:8.3.1-community […]

  • Vue finishing


    1、 Vue Vue is a front-end framework that follows MVVM architecture pattern NPM import path:https://cdn.jsdelivr.net/npm/[email protected]/dist/vue.js MVVM architecture model data view template ViewModel processing data 1. Common syntax of ES6: Variable definition, VaR, let, const Var variable promotion, function scope, global scope, redefinition will not report an error, can be re assigned Let block level scope […]

  • Custom debug function used in C / C + + Development


    1、 Colorless version 1、 Custom printf #include <stdio.h> #ifdef MYDEBUG #define DEBUG(arg…) {\ printf(“[debug]:%s:%s:%d —->”,__FILE__,__FUNCTION__,__LINE__);\ printf(arg);\ fflush(stdout);\ } #else #define DEBUG(arg…) {} #endif Call instance: DEBUG(“my debug……\n”); DEBUG(“the a is %d\n”,a); 2、 Custom printf #ifdef DEBUG #define D_STR(_STR_) printf(“f:%s(l:%d)%s\n”,__FILE__,__LINE__,_STR_); #define D_LINE printf(“f:%s(l:%d)-fn:%s\n”,__FILE__,__LINE__,__FUNCTION__); #define D_CHAR(_CHAR_) printf(“f:%s(l:%d)%d\n”,__FILE__,__LINE__,_CHAR_); #define D_HEX(_HEX_) printf(“f:%s(l:%d)[%x]\n”,__FILE__,__LINE__,_HEX_); #else #define D_STR(_STR_) ; #define D_LINE ; […]

  • Pgboxer best practices: series four


    Author: Wang Zhibin, a former PGCE of China, is an official certified lecturer of PostgreSQL and a specially invited gold medal lecturer of Pangu cloud classroom. Finally, let’s talk about the deployment forms of pgboxer, including single application scenario, multi application scenario, cluster scenario and multi instance scenario. These methods are all based on different […]