Programming VIP

Introduction: in the morning, I received a text message with the content of "Dear Hello, XXX". At that time, I smiled. It's a joke that programmers can Get. It shows that the program doesn't Get my name correctly from the database, and then formats the null value as null. To get back to business, the reason for this situation i ...

MySQL sub database and table can be realized through the middleware Mycat. This paper briefly introduces several partition strategies of Mycat, mode, range and hash, and tests and verifies them respectively 1. MySQL implements database and table splitting based on Mycat 1.1 principle of warehouse and table division Data sharding can be div ...

1. Introduction We can see that the main data structures used in redis include: simple string (SDS), linked list, dictionary, compressed list, integer set, etc. Redis objects are implemented by these data structures. Moreover, in order to select more appropriate data structures for different objects in different use scenarios, redis has cr ...

1. The whole story One cool afternoon, I saw a news that the interface was being mechanically called. I suspected that someone was using script to brush the interface (mainly to divert water from the platform). what? No, the general interface request is encrypted. Unless you know the encryption key and encryption method, the call will not ...

Master-slave database Install docker Please refer to my other article: https://blog.csdn.net/m0_46435741/article/details/121502952 Create a new instance of the main mysql container Create a container with mysql version 5.7. Mount data volume: Mount the configuration file to the host Directory: / mydata / MySQL master / conf Mount the log ...

1. The database data is damaged due to misoperation of drop statement. Please write down the recovery idea and actual general steps? #The recovery of all data depends on backup. If there is no backup, it cannot be recovered In case of recovery after misoperation, the incremental recovery method shall be used for recovery. The specific steps ...

Pyspark establishes Spark RDD Each RDD can be divided into multiple partitions. Each partition can be regarded as a data set fragment and can be saved to different nodes in the Spark clusterRDD itself has fault-tolerant mechanism and is a read-only data structure, which can only generate new RDD through transformation; An RDD can be proces ...

thank Thank you, Mr. Zhou Yang ❤️❤️ Station b video address Uninstall previous version View the installed MySQL RPM - qa|grep - I MySQL Uninstall mysql-community-server-5.6.36-2 one by one using Yum remove el7. x86_ sixty-four Installation of MySQL for Linux Download MySQL installation package wget https://dev.mysql.com/get/mysql57-comm ...

0. General MySQL basic notes, review and useEnvironment construction: detailed installation steps of MySQL database nameexplaincommandDDL (data definition language)Define and manage data objects, such as databases, data tables, etccreate,drop,alterDML (data operation language)Used to manipulate data contained in database objectsinsert,update, ...

Redis publish and subscribe Redis publish / subscribe (pub/sub) is a message communication mode: the sender (pub) sends messages and the subscriber (sub) receives messages Redis client can subscribe to any number of channels Subscribe / publish message diagram: The following figure shows the relationship between channel 1 and the thre ...