MySQL

1, MySQL database when the slow query, is more dangerous, once there are other DDL operations, may cause the entire database waitingCan be divided into the following situations:When the table is a MyISAM table, the table has a slow query, does not

1, the cause of the error:Today received Zabbix disk alarm, through the du command to find the MySQL directory is too large, found that the relay log does not set the expiration time, so manually remove the relay log from the library, after

mysq version: 5.7.21Operating system: Linux (Ubuntu)  The basic idea of the whole operation is as follows (including the solution idea of the problem, you can see the final command summary first if you want to solve the problem directly)  Check

Table structureOne DB for a folder.One table two files The frm is a table structure, and IBD is the storage dataConnection layer:SockIpSQL Layer:Storage tiers: MY.CNF Read Order Observing the startup process (data directory) - 授权用户(

Tag: Init row off SSI time down table function valueFirst, show profilesSee if the Profiles feature is turned onmysql> show variables like ‘profiling‘;+---------------+-------+| Variable_name | Value |+---------------+-------+| profiling | OFF

stored procedures, which can be said to encapsulate some functionality together, are equivalent to stored procedures, in MySQL functions and stored procedures are two different things, do not confuse. To establish a stored procedure:1. Declaring

1, limit [offset, 0 means no offset, in the first row, 1 for the offset line, in the second row; The default value is 0] the number of records to showApplication of pagination:int curpage = 2;int pageSize = 10;int offSet = (curPage-1) *

To back up the database:/usr/local/kkmail/service/mysql/bin/mysqldump-u kkmail-p--databases Kkmail |gzip>20180309.sql.gzRestore the database:Stop the database-related services, unzip the backed up SQL database files, restore the database, and

MySQL Master master installation configuration:Pre-Installation Confirmation: Version number, check code (md5sum), port number, installation pathInstallation dependencies:Yum install gcc gcc-c++-yYum Install Cmake-yYum Install Ncurses-devel

Today, let's take a look at the ten improvements that MySQL8.0 improves database administrator productivity.It's not easy to find 10 points from a lot of features, here are the ten features:1. Improvements to temporal tables2. Persistent global

I. Introduction to the LibraryINFORMATION_SCHEMA: Virtual library, do not occupy disk space, storage is the database startup parameters, such as user table information, column information, permission information, character information and so on

The syntax of a single-table querySELECT Field 1, Field 2 ... From table name WHERE condition GROUP by field have filter ORDER by field limit number of bars Second, the execution order of the

之前在[《MySQL性能管理及架构设计》请添加链接描述](https://coding.imooc.com/class/49.html)课程中为大家讲解了如何使用Maxscale来实现数据库的读写分离的方案。近期在课程交流群中有同学提出在使用Maxscale2.2版本时，无法自动加载MySQL5.7中的用户信息。 所以我就研究了一下新版本的Maxscale，发现确实如此，这是什么原因呢？由如何解决这个问题呢？Let's start by saying why, let's take a

There are two ways to modify a global variable, the first of which is to modify the configuration file, and the second is to set the value of the global variable by the SQL statement. (Refer to: http://www.cnblogs.com/qlqwjy/p/8046592.html)0.

MySQL Proxy MySQL Proxy is a simple program that is located between your client side and the MySQL server to monitor, analyze, or change their communications. It is flexible, unlimited, and common uses include: load balancing, failure, query

10 SQL statement optimization techniques to improve MYSQL query efficiency, mysqlsql The execution efficiency of the MySQL database has a great impact on the execution speed of the program. It is very useful to effectively process and optimize the

Iscsi linux client, iscsilinux Use of iSCSI Linux clientsIn Linux, you need to install the ISCSI client software iscsi-initiator. The installation process is as follows:Step 0: Install the iSCSI client software through yum or rpm.Step 1: Configure

Mysql: implements the median algorithm and mysql median algorithm. Purpose: Mysql does not have a specific median algorithm. For those unfamiliar with SQL, median can only be written in JAVA or other languages. It is not recommended that you use

Proxysql read/write splitting configuration, proxysql read/write splitting ProxySQL is the read/write splitting middleware promoted by Percona. It is:Https://www.percona.com/downloads/proxysql/ I. Installation 1: Download wget pull-ivh proxysql-1.4.5

Basic Mysql user operationsCreate a user: mysql> create user 'cai'@'localhost' identified by '123456';Query OK, 0 rows affected (0.00 sec)mysql> select user,host from mysql.user; +-----------