explain analyze in MySQL 8.0

Original address: https://mysqlserverteam.com/mysql-explain-analyze/   MySQL 8.0.18 was just released. October 17, 2019 ), which includes a new feature to analyze and understand how queries are executed: explain analyze. What is explain analyze EXPLAIN ANALYZE is a query analysis tool that tells you how much time MySQL spends on queries and why ...

Added by dw89 on Fri, 29 May 2020 19:45:52 +0300

0. Chapter 0 of MySql, installation and cluster configuration

Chapter 0 of MySql, installation and cluster configuration 1, MySql installation 1. RPM installation RPM installation, unable to customize some installation paths and configuration file paths ##Fill in the pit later 2. Generic installation Binary precompiled Generic, download address: https://cdn.mysql.com/archives/mysql-5.7/mysql- ...

Added by khendar on Tue, 26 May 2020 17:54:42 +0300

Optimistic Lock (CAS) retry data version not updated under mysql transaction default isolation level

Exception Information Ccom.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Lock wait timeout exceeded; try restarting transaction Reasons for the problem When optimistic locks modify data, the data version number has been modified, causing the modification to fail. When retrying the modification, each time the data read from the d ...

Added by xsist10 on Fri, 22 May 2020 21:51:58 +0300

Basic usage of JDBC

JDBC fixing steps: Load driver String url="jdbc:mysql://localhost:3306/jdbcstudy?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT"; String username="root"; String password="123456"; Class.forName("com.mysql.cj.jdbc.Driver");//I don't know why com.mysql.jdbc.Driver will report an error. Please leave a message if you have any ...

Added by PHPfolife on Wed, 20 May 2020 17:31:54 +0300

Introduction to Connection-Control for MySQL

In Oracle and SQL Server databases, you can set up some complex account password policies, such as locking an account more than N times after a failed login, so can you do the same in MySQL?The answer is that MySQL has similar capabilities, except in MySQL it delays the response time when its login fails beyond the threshold, instead of locking ...

Added by marco839 on Tue, 19 May 2020 20:23:28 +0300

Consul configuration center of Spring Cloud series

We have learned about Spring Cloud Config before: Consul configuration center of Spring Cloud series (I) Consul configuration center of Spring Cloud series (2) Consul configuration center of Spring Cloud series (3) It provides the function of configuration center, but it needs to cooperate with git, svn or external storage (such as various da ...

Added by synergypoint on Mon, 18 May 2020 09:51:39 +0300

MySQL database functions

1, Date and time functions 1. Function to get the current dateIt's the same. It's different CURDATE() : Used to get the current date of the system CURRENT_DATE() Used by the system to get the current date mysql> select CURDATE(),CURRENT_DATE(); 2. Get function of current time CURTIME() : Used to get the current time of the system mysql& ...

Added by brighton on Thu, 14 May 2020 12:11:49 +0300

Prometheus+Grafana visual monitoring MySQL

Use Prometheus and Grafana to monitor MySQL server performance.Use two exporter s:Node? Exporter: server system data collectionmysqld_exporter: MySQL server data collectionMonitoring architecture: Prometheus installation configurationInstallation mode binary installation, see here for details CentOS7 deployment PrometheusVersion: current late ...

Added by dhruvasagar on Thu, 14 May 2020 02:15:46 +0300

Issue 04: column CHECK constraint

check constraint means to filter one or more columns according to certain preset rules. If the condition is true, the filtering succeeds; if the condition is false, the filtering fails and the failure code is returned to the client. Why do you want to list and write this separately? You often encounter irregular SQL. In many cases, you can onl ...

Added by AndyB on Wed, 13 May 2020 12:25:22 +0300

MySQL 8.0 InnoDB supports instant add column

Original address: https://mysqlserverteam.com/mysql-8-0-innodb-now-supports-instant-add-column/   For a long time, instant DDL has been one of the most popular InnoDB functions. For the growing and fast-growing data set, any network scale database must have the function of executing DDL immediately. Developers often need to add new columns to m ...

Added by coolfool on Tue, 12 May 2020 16:55:02 +0300