MySQL

Places to be aware of:1. Primary server (Master), from the server (slavethe version of the database cannot be exaggerated and can be minor version differences. But from the server'sMySQLversion try not to be less thanMasterof theMySQLversion.

Query the SQL statement that all databases consume disk space size:Select Table_schema, concat (Truncate (SUM (data_length)/1024/1024,2), ' MB ') as Data_size,Concat (Truncate (SUM (index_length)/1024/1024,2), ' MB ') as Index_sizeFrom

Method One:MySQL mistakenly delete rootFirst step: Mysqld_safe--skip-grant-tables--skip-networking & (Skip password start)Step two: Add Root tableInsert into user set user= ' root ', ssl_cipher= ', x509_issuer= ', x509_subject= ';Step three: Root

Large web site in order to solve a large number of high concurrency access problems, in addition to the site to achieve distributed load balancing, far from enough. To the data business layer, the data access layer, if the traditional data structure,

Sometimes when you start the MySQL server will error, according to the log show lost Mysql.sock file650) this.width=650; "src=" Http://note.youdao.com/yws/res/144/955BC22505374741BCB43FC950048F0F "alt=" 955bc22505374741bcb43fc950048f0f "/>Process:

1,myisam on disk, store the data as 3 files. The first is a table structure file whose name starts with the name of the table, the. frm file, the second file is a data file with a. MYD extension, and the third is an index file with an extension of.

In the previous blog in succession to record the query efficiency of the article. Today in the collation, write some of their own notes are as follows:Common reasons for slow queries are as follows:1. No index or index is not used.PS: Indexes are

STEP1: Check to see if the installation Yum List installed mysql*If it is already installed, go to step4 boot. Otherwise continueStep2 to see if there is an installation package: Yum List mysql* If there is no installation package to download the

Let's start by saying something:MySQL's InnoDB and MyISAM are the two most common table types used in MySQL, each with its pros and cons. The main difference between the two types is InnoDB Transactional and foreign key and row level locks are

1. Connect the MySQL database, select the Name field, and place the class file in the Tomcat installation file directory/webapps/test/web-inf/classes1 Importjavax.servlet.ServletException;2 ImportJavax.servlet.http.HttpServlet;3

Detects MySQL master-slave status and, if never synchronized, sends an e-mail to the OPS person. Use timed tasks for second-level monitoring!# -*- coding: utf-8 -*#! /usr/bin/env pythonfrom fabric.api import

MY.CNF content is as follows# for advice The Change settings see# http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html[client]# Password=... # Port=... # socket=. ..

MySQL Console error messageC:\users\haihai187>mysqlERROR 1045 (28000): Access denied for user ' ODBC ' @ ' localhost ' (using password:nO)SolutionsFirst: C:\users\haihai187>mysql-u root-pEnterEnter Password: *********EnterWelcome to the MySQL

Install MySQL online under UbuntuThe command is as follows:1.sudo apt-get Update #更新软件包2.sudo apt-get Install Mysql-server #安装服务器3.sudo apt-get Install mysql-client #安装客户端4.sudo apt-get Install Libmysqlclient-dev #mysqlAPi开发包5.sudo Netstat-tap |

Three big data types: numeric, time date, string.valueintegerIs there a signcreate table tab_int(a tinyint unsigned,b tinyint,c SMALLINT,d MEDIUMINT,e INT,f bigint);insert into tab_int values(255,-128,2423,-4323,-14432,4356546);select * from tab_int;

The modified users are listed as root.first, the root of the original myql password;Method One:Outside the MySQL system, use the Mysqladmin#mysqladmin-u root-p Password "test123"Enter Password: "Enter the original password"Method Two:By logging into

A few common sense about MySQL privilege:1, MySQL's authority system is mainly used to verify the user's operation rights.2, Inside MySQL, the permission information is stored in the MySQL database granttable. When MySQL starts, the information in

MySQL's universal "nested loops" are not optimal for every type of query. But fortunately, the MySQL query optimizer onlyA few queries do not apply, and we can often make MySQL work efficiently by rewriting queries.Let's take a look at the

As we all know, MySQL is the most important in all it enterprises, Linux OPS personnel can master MySQL database technology, will be very helpful to the future high-paying career development! Linux operations must be MySQL Enterprise face question

Sometimes we use the SET command to set the value of a variable, but we encounter some error message, that is: You cannot set this variable to "value".Example:Set global sql_log_bin=0;The following error message is reported:mysql> set global sql_log_