Postgres Partition Table II
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 ...
Added by lordphate on Sat, 05 Mar 2022 01:19:37 +0200
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 ...
Added by spxdcz on Sat, 05 Mar 2022 01:06:07 +0200
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: ...
Added by sunnyside on Fri, 04 Mar 2022 11:02:58 +0200
1. Multi table query:
1. Query syntax:
Column name list
Table name list
2. Prepare sql
Create department table
CREATE TABLE dept(
id INT PRIMARY KEY AUTO_INCREMENT,
INSERT INTO dept (NAME) VALUES ('Development Department'),('Marketing Department'),('Finance Department');
Create employee tabl ...
Added by Celadon on Fri, 04 Mar 2022 10:13:52 +0200
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 ...
Added by Sanjib Sinha on Fri, 04 Mar 2022 08:54:45 +0200
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 ...
Added by aeonsky on Fri, 04 Mar 2022 03:55:35 +0200
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
2. Introduction and installation
Similar to Scrapy, feapder supports l ...
Added by nickiehow on Fri, 04 Mar 2022 00:23:05 +0200
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 ...
Added by Placebo on Thu, 03 Mar 2022 15:31:53 +0200
As we all know, Redis has five storage structures: String, List, Set, Zset and Hash
1.1 single character writing and query
1.2 batch string writing and query
1.4 set expiration time
1.6 numerical calculation
1.7 string splicing
2.1 queue (right in left out)
2.2 stack (ri ...
Added by Dingbats on Thu, 03 Mar 2022 06:17:47 +0200