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Postgres Partition Table II 1, Background   in the previous article Postgres partition table I In, we mentioned that there are some differences in the way Postgres creates and uses partition tables after version 10.0. This article will mainly introduce the creation and use of partition tables after Postgres 10.0.    after we cr ...

1 - learning objectives What do you do? What are the advantages? For which scenarios?What are the cluster schemes?Compared with other similar databases, what are the advantages and disadvantages?Detailed explanation of configuration file, how to optimize performance?Basic operation, data backup and recoveryQA summary 2 - what do you do? What ...

1, Introduction Why constraints Data Integrity refers to the Accuracy and Reliability of data. It is proposed to prevent the existence of data that does not comply with the semantic provisions in the database and to prevent invalid operation or error information caused by the input and output of error information. Entity Integrity: ...

1. Multi table query: 1. Query syntax: select Column name list from Table name list where.... 2. Prepare sql Create department table CREATE TABLE dept( id INT PRIMARY KEY AUTO_INCREMENT, NAME VARCHAR(20) ); INSERT INTO dept (NAME) VALUES ('Development Department'),('Marketing Department'),('Finance Department'); Create employee tabl ...

Introduction to persistence Redis is an in memory database. If the database state in memory is not saved to disk, the database state in the server will be lost once the server process exits. So redis provides persistence function! What is persistence The working mechanism of using permanent storage media to save data and recover the saved ...

DML language Data operation language: Inserting: insert ing Modify: update Delete: delete 1, Insert statement Mode 1: Syntax: insert into table name (column name...) Values (value 1,...); Features: it supports inserting multiple rows and querying subsets SELECT * FROM beauty; 1. The type of the inserted value should be consistent or com ...

1. Preface As we all know, Python's most popular crawler framework is Scrapy, which is mainly used to crawl website structural data Today, we recommend a simpler, lightweight and powerful crawler framework: feapder Project address: https://github.com/Boris-code/feapder 2. Introduction and installation Similar to Scrapy, feapder supports l ...

MySQL [Delete error] uses binlog to quickly roll back (python script is not required) Locate binlog position according to misoperation time In specific usage scenarios, binlog may store hundreds of thousands or more pieces of data, and the amount of data reaches the size of G. therefore, determining the location of binlog needs to be filtered ...

(1) Read the configuration file of MyBatis. mybatis-config.xml is the global configuration file of MyBatis, which is used to configure database connection information. (2) Load mapping file. The mapping file is the SQL mapping file, in which the SQL statements for operating the database are configured, which needs to be in the MyBatis config ...

As we all know, Redis has five storage structures: String, List, Set, Zset and Hash catalogue 1. String 1.1 single character writing and query 1.2 batch string writing and query 1.3 deletion 1.4 set expiration time 1.5 setnx 1.6 numerical calculation 1.7 string splicing 1.8 bitmap 2. list 2.1 queue (right in left out) 2.2 stack (ri ...