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preface dynamodb is a non relational database of AWS. It is applicable to big data without frequent addition, deletion, modification and query and with weak relevance, such as the historical order information of a user. Historical orders may not be queried frequently, but the amount of data is large, and they can be queried as long as there is ...

The original content of GreatSQL community cannot be used without authorization. Please contact Xiaobian and indicate the source for reprint.In order to experience GreatSQL for community users, we also provide Docker images. This article describes in detail how to deploy GreatSQL in Docker and build an MGR cluster.The operating environment invo ...

Common problems in redis development - cache penetration - cache avalanche - redis brain crack - cache breakdown preface In our daily development, we all use the database to store data. Because there is usually no high concurrency in general system tasks, it seems that there is no problem. However, once the demand for a large amount of ...

Filter data This chapter will teach you how to specify search criteria using the WHERE clause of a SELECT statement. Use WHERE clause Databases generally contain a large amount of data and rarely need to retrieve all rows in the table. Usually, only part of the table data will be extracted according to the requirements. To retrieve only the ...

sql language Overview and function **Overview: * * structured query language is abbreviated as SQL, and SQL statement is a language for database operation. **Function: * * you can add, delete, modify and query the data in the database, tables and tables in the database management system through Sql language. <br/ > sql classification ...

Operating environment: Development tools: IDEA /Eclipse Database: mysql5 seven Application service: Tomcat7/Tomcat8 Using framework: Spring + spring MVC + mybatis Project introduction Nowadays, great changes have taken place in our computer-based lifestyle. The rapid development of the Internet makes everyone pay attention to the value of th ...

concept Master Slave replication refers to copying data from one Redis server to other Redis servers. The former is called master/leader and the latter is called slave/follower; Data replication is unidirectional and can only be from master node to Slave node. Master mainly writes, Slave mainly reads. Master-slave copy, read-write separation! ...

In work, we delete data or database by mistake. Do we have to run away? I don't think so. Programmers must learn to save themselves and retrieve the data unconsciously. In MySQL database, we know that binlog logs record all our operations on the database, so binlog logs are a sharp tool for us to save ourselves. Today, taking MySQL databa ...

The original content of GreatSQL community cannot be used without authorization. Please contact Xiaobian and indicate the source for reprint.Content outline1, Test environment construction2, Execute process resolution3, Precautions1, Test environment constructionFirst, create a table and insert several rows of data fields:CREATE TABLE t (s1 INT ...

Data preparation 1. Student form Student(SId,Sname,Sage,Ssex) – SId student number, Sname student name, Sage date of birth, Ssex student gender create table Student(SId varchar(10),Sname varchar(10),Sage datetime,Ssex varchar(10)); insert into Student values('01' , 'Lei Zhao' , '1990-01-01' , 'male'); insert into Student values('02' ...