• Analysis of local memory in Android studio 4.1


    This article isWhat are the new features of Profiler in Android studio 4.1The second part of the article. Previous articles focused on introductionNew features of system trace in Android studio。 We learned from your feedback that it is very difficult to debug local memory with C + +, especially when developing games. In Android studio […]

  • The execution process of a SQL statement in MySQL


    First look at the architecture of MySQLIt can be said that the main architecture of MySQL is divided into server layer and storage engine layer. Connector: mainly responsible for user login database, user authentication, includingCheck account password, authority and other operationsIf the password of the user’s account has passed, the connector will query all the […]

  • Using build analyzer in Android studio to improve build performance


    As a member of the Android Developer Tools team, my team members and I make various tools with the idea of making Android the best Mobile Developer Platform every day. This means that we will build some tools to help you develop your application, so that you can focus on writing your application. We know […]

  • Lexical analyzer


    Wikipedia: lexical analysis is the process of transforming character sequence into marker sequence in computer science.A program or function that performs lexical analysis is called a lexical analyzer. There is the following original program code add_result = 1 + 2 The results are as follows NAME `add_result` 0, 0 SYMBOL `=` 0, 11 INT `1` […]

  • Lexical analysis with bklexer


    A few days ago, I have packaged the lexical analyzer and named itBKLexer, currentBKLexerGo / C + + / Python is supported respectively. The program code is in the GitHub projectClick on the project page You can refer to thetry_lexerCode learning, take go as an example: package main import ( “fmt” “strconv” “./bklexer” ) func […]

  • How to execute a SQL statement in MySQL


    An analysis of MySQL infrastructure 1.1 overview of MySQL basic architecture The figure below is a brief structure diagram of MySQL. From the figure below, you can clearly see how the user’s SQL statements are executed inside mysql. Let’s briefly introduce the basic functions of some components involved in the figure below to help you […]

  • Infrastructure: how is an SQL query executed?


    Reading guide MySQL is a hot spot in small and medium-sized enterprises. At present, as one of the mainstream databases, few back-end developers will not use it, but as an old driver, it is not enough to just use it. Today, through a simple query statement to talk about the internal execution process of MySQL. […]

  • What are the steps in the execution of MySQL logical architecture SQL statements


    What are the steps in the execution of MySQL logical architecture SQL statements From the perspective of MySQL architecture, we can disassemble MySQL into several parts, as shown in the figure below In general, MySQL can be divided intoServer layerandStorage engine layerTwo parts. The server layer includesConnector, query cache, analyzer, optimizer, executor, covering most of […]

  • How is an SQL query executed?


    What parts does MySQL have? Connectors: Manage Connections, verify permissions. Analyzer: lexical analysis, grammatical analysis. Optimizer: execution plan generation, index selection. Executor: operate the storage engine and return the result. Storage engine: store data and provide read-write interface. Connector The first step is to connect to the MySQL database, which is to connect to the […]

  • Analysis of MySQL infrastructure


    The article has been hosted to GitHub, you can go to GitHub to check and read, welcome to star! MySQL infrastructure 1、 Introduction When we learn mysql, the first step is to understand and install the MySQL client, and then use Mysql to do a series of database operations. But what we often ignore is […]

  • The execution flow of a query statement


    Execution of an update statement: This article comes from the experience of reading “45 lectures on MySQL” 1. ConnectorResponsible for managing the connection session with the client and obtaining the permission of the connecting user 2. AnalyzerResponsible for lexical analysis, syntax analysis, generate commands to be executed 3. OptimizerGenerate the execution plan, calculate the time […]

  • Why SQL Server2008 order by cannot be used directly in the union clause


    According to the requirements, each takes top 20. Since it is random, SQL Server order by newid() is used, and then all the data are unionized. So I immediately gave the answer: select top 20 * from xxx where type=1 order by newid()    union    select top 20 * from xxx where type=0 order by newid()   But the SQL query analyzer is wrong and the syntax is wrong. At first […]