Programmer Think

Master-slave database theoretical knowledge First step The master's operations on the data are recorded in the Binary log. Before each transaction updates the data, the master records these changes and writes them to the Binary log serially. After completing the log writing, the master notifies the storage engine to commit the transaction. T ...

The original content of GreatSQL community cannot be used without authorization. Please contact Xiaobian and indicate the source for reprint.1. Switch the master node2. Switch single master / multi master mode3. Add a new node4. Delete node5. Add back the node that exited abnormally6. Restart MGR cluster7. SummaryReferences, documentsDisclaimer ...

In the development process, it is sometimes encountered that only a part of a certain field of the database is required. Sometimes, this scenario is more convenient and faster to operate directly through the database than through code. MySQL has many string functions that can be used to deal with these requirements, such as left, right, subs ...

688. Knight's probability on the chessboard 2022.2.1 one question per day Title Description On an n x n chess board, a knight starts from a row (column) and tries to make k moves. Rows and columns start at 0, so the upper left cell is (0,0) and the lower right cell is (n - 1, n - 1). Chess knight has 8 possible walking methods, as shown in ...

Server communication process Server: 1,adopt socket()Function to create a to receive a connection request socket 2,To construct the host connection address sockaddr_in structural morphology,include sin_family,sin_port,sin_addr Three members 3,binding sockaddr_in Structure and socket 4,adopt listen()Function will stocket Set to listenin ...

1, PrefaceSpringBoot 2.6.x does not recommend the use of circular dependency, which is good news. Springboot gradually guides developers to write standard code from the bottom. At the same time, it is also sad news. The application scenarios of circular dependency are too wide.If you upgrade from a lower version to 2.6 x. Then the first problem ...

prefaceWhether it is ID generation in distributed systems or the generation of unique numbers such as requesting serial numbers in business systems, it is a scenario that software developers often face. The snowflake algorithm is a solution to these scenes.Taking distributed ID as an example, its generation often requires uniqueness, increment, ...

File contains Thinking: the function of PHP requires that the function must be called in memory, but the function is written in the corresponding PHP file one by one. Must the code in other files be copied to access it? Introduction: if the corresponding function in a file has been written, if you want to use it in other PHP files, yo ...

typedef enum { RESET = 0, SET = !RESET } FlagStatus, ITStatus; This sentence means to alias enum {reset = 0, set =! Reset}: FlagStatus and ITStatus The FlagStatus and ITStatus that appear after this can be regarded as enum {reset = 0, set =! Reset} The purpose of this is to save code, improve readability, and be easy to maintain~ 1. De ...

10. Multi table query of mybatis Relational database tables are divided into * one-on-one * One to many * Many to many give an example The ID number is one to one. A person can only have one ID number. An ID number can only belong to one person.Users and orders are one to many, and orders and users are many to one One user can place multip ...