Sometimes we need to save a lot of data, which is time-sensitive, such as some logs. After a period of time, the existence of these data is not significant, and in addition to taking up a lot of hard disk space, it may make data queries slow.This data needs to be cleaned up regularly.We can cope with ...
Posted by timtom3 on Sat, 20 Jun 2020 17:56:03 -0700
Adding fields to a table of ten million or more levels in MySQL has always been a headache. In this case, how to deal with it? This paper uses three common scenarios to illustrate the case.
1. Environmental preparation
Database version: 5.7.25-28 (Percona branch)
Server configuration: three centos 7 virtual machines with 2CPU 2G memory
Posted by romilbm on Fri, 19 Jun 2020 23:20:57 -0700
Introduction of master and slave
What is master-slave?
MySQL master-slave replication is one of its most important functions. Master-slave replication refers to that one server acts as the master database server and another or more servers act as the slave database server, and the data in the master ...
Posted by grimz on Fri, 19 Jun 2020 05:48:13 -0700
SELECT pf1001.attrId, attrCode, attrName,
when '04' THEN CONCAT('product-',(select productName from pf1003 where productId= pf1001.scopeId))
WHEN '03' THEN CONCAT('Product line-',(select productLineName from pf1004 where productLineId= pf1001.scopeId))
WHEN '02' THEN CONCAT( ...
Posted by philwhite on Thu, 18 Jun 2020 03:29:30 -0700
Hunt Framework is a full stack Web framework developed in D language, similar to Laravel / SpringBoot / Django, etc., which enables D language developers to create projects quickly. The built-in super multi business specifications are convenient for developers to use out of the box, and convenient for managers to review project code more easily ...
Posted by jesse_james on Thu, 18 Jun 2020 02:11:58 -0700
Finish MySQL in half a day (all)
Finish MySQL (all) 1 in half a day
The blogger uses MySQL version 8.0, and the storage engine is InnoDB. We don't explain InnoDB in detail here. If necessary, we recommend you to know This article Blog (or Baidu) https://www.jianshu.com/p/519fd7747137
3A. Add, delete, ...
Posted by pella.d on Wed, 17 Jun 2020 23:46:05 -0700
Recently, the task is relatively light, and I have free time to learn learning technology, so I come to study how to realize the separation of reading and writing. Here we use blog to record the process. On the one hand, it can be viewed in the future, and on the other hand, it can also be shared with you (most of the information on the Interne ...
Posted by ctoshack on Tue, 16 Jun 2020 23:22:11 -0700
Create a test table
Create the corresponding JavaBean
Create mybatis configuration file and sql mapping file
MyBatis operation database
Create MyBatis global profile
The global configuration file of MyBatis contains settings and properties information, such as database connection pool information, which affect MyBatis' ...
Posted by sumolotokai on Tue, 16 Jun 2020 20:27:06 -0700
Previous writing is too messy, turn it out and reorganize it
Small Catalog Series:
(1) Getting started with MySQL is not a big problem
(1) introducing constraints
(1) Where do constraints occur?
To explain constraints, you need to know where and why constraints are used.
The SQL language completes the definitio ...
Posted by gacon on Tue, 16 Jun 2020 18:12:15 -0700
Article content output source: Lago education Java high salary training camp.
This article is part of the notes in the MySQL learning course.
This post explains in detail how to build MySQL with high availability and provides a solution to solve the problem that the common master-slave replicat ...
Posted by sgtbash on Sun, 14 Jun 2020 21:38:57 -0700