• Issue 12: performance monitoring of compression meter


    LastHas solved the concept of compressed table, the impact of index page and simple use. This article mainly introducesHow to observe the compressed table. 1、 Classification of usage scenarios of compressed tables 1. Select business This kind of operation does not need to decompress the compressed page, soPerfectUse compressed tables. 2. Insert service This kind […]

  • Jpg learning notes 5 (with complete code)


    The fourth step of JPG compression is Huffman coding. The following is mainly about the Huffman coding of JPEG. The picture is quoted from “compressed image file formats, JPEG, PNG, GIF, XBM, BMP – John Miano” [1] 1. Huffman symbol of AC data For AC data, the first four bits to be encoded represent how […]

  • Pointer passing of reference object


    The instance of the reference object represents a memory pointer. When modifying the properties of the reference object, the information in memory will change accordingly. If the reference object is new, it represents a new pointer. The change will not affect the object pointed to by the previous pointer. Similarly, after the new below, the […]

  • So called HTML5


    The so-called HTML5 actually means that HTML has developed to the fifth generation. Of course, this term now refers to a lot in a broad sense. In addition to just mentioning that it is the fifth generation of HTML, it also represents many new tags and downward compatibility. Even when it is referred to as […]

  • Project and package problems of eclipse import folder


    When using eclipse, you sometimes need to work from an existing folder At this time, you need to first create a new Java project in eclipse, then File > Import > file system, and select the parent folder of the file to import However, at this time, the problem of “the declared package does not […]

  • Tkinter (22) standardized appearance and options database


    Use the options database to set the default option values of the components. In addition, you can use the preset file. xdefaults fileEach part has a category name, which is basically the same as the category constructor, for example, the button isButtonIt can also be named by itself; another name is just like the instance […]

  • Blue Bridge Cup Sanyang xianrui


    For more articles, please pay attention to the official account of “BLOG of the sea“. problem Observe the following addition formula: Auspicious and bright +Sanyang xianrui —————- Sanyang is lucky Among them, the same Chinese characters represent the same number, different Chinese characters represent different numbers, and “three” and “Xiang” cannot be zero. Please figure […]

  • Gaode map API, map type switch (satellite map)


    Common controls AMap.MapType : map type switch plug-in, which can be used to switch satellite map First of all, remember to introduce plug-ins Add control map.addControl () map <span style=”background-color: #f5f5f5; color: #800000;”> *</span><span style=”background-color: #f5f5f5; color: #000000;”>{</span><span style=”background-color: #f5f5f5; color: #ff0000;”>margin</span><span style=”background-color: #f5f5f5; color: #000000;”>:</span><span style=”background-color: #f5f5f5; color: #0000ff;”>0</span><span style=”background-color: #f5f5f5; color: #000000;”>;</span><span style=”background-color: […]

  • Service tree series (1): what is a service tree and its core functions


    preface Service treeThis term is familiar to almost all students of operation and maintenance and operation and maintenance development, but we don’t know the principle of service tree and why to use service tree estimation. This paper first discusses these basic concepts, and then discusses how to realize them. The following figure is the core […]

  • How to use shell to write a command to display the directory structure?


    Using in LinuxShellWrite a command to display the directory structure to quickly find the directory structure. 1. Code #!/usr/bin/env bash #This command is used to display the file structure of the specified path or current path, and supports search #TF displays the file structure of the current directory #TF search current directory by keyword #TF directory […]

  • Tkinter (44) event


    In some cases of our program, we call the event. We link the event and related parameters to a function, called binding. When the event occurs, the function will be called. The event related content is divided into three parts: event event, callback function callback and binding Level of binding Binding components, usingbind()method Binding part […]

  • Full entry record of. Net core microservices (5) — Ocelot API gateway (2)


    Tips: This article has been added to the reading list of series articles. You can click to see more related articles. preface In the last article, the basic construction of Ocelot API gateway has been completed, and the unification of service entrance has been realized. Of course, this is only one of the most basic […]