MySQL

Ubuntu install MySQL can't find Mysql.sock solutionRestart MySQLView MySQL LogsGedit/var/log/mysqld/err.logcan find no Mysql.sockBut there is a mysqld.sockFile address directory:/var/run/mysqld/mysqld.sockWill php.ini the following

Type name Display length Database type Java type JDBC Type index (int) Describe VARCHAR L+n VARCHAR Java.lang.String 12 CHAR N CHAR Java.lang.String 1

1, the configuration of the environment, mainly to install MySQL and download the connection required package (I use Mysql-connector-java-5.1.3-rc-bin.jar)2, registered driver Class.forName ("Com.jdbc.mysql.Driver");3. Create connection Connection

MySQL free spaceSome tables in the production system use Delete to delete some rows and find that the space is not releasedReason: The principle of high water mark generation by analogy with OracleWorkaround:1. Execute OPTIMIZE table name;Attention:1

Key_buffer_size is one of the most influential parameters for MyISAM table performance, and the following is a configuration of the primary storage engine server with MyISAM:mysql> SHOW VARIABLES like '%key_buffer_size% ';　　See the usage of

Data structure of the index in MySQL:1, basically all indexes are b-tree structure, part also has the hash index.2. Index classification (function)Primary KEY index: there is at most one primary key index in a table, and the field value cannot be

For MySQL data installation method, there are many tutorials on the web, you can refer to the webpage http://www.duote.com/tech/1/2430.html#contentbodyIt is important to remember the path where you store your data. For your own backup use. When you

1. Error descriptionOrg.hibernate.exception.SQLGrammarException:error executing Workat Org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert (sqlexceptiontypedelegate.java:80) at

Environment: Centos 6.6 64-bitServer:Master node: GUOLETAOTEST01 IP Address: 192.168.2.25Slave node: GuoletaoTest02 IP Address: 192.168.2.26VIP Address: 192.168.2.30 A DRBD environment is built: 1) Add additional libraries:Official

MySQL is nothing more than a subquery and two ways of connecting.The first table is Table1, the second is table2, and Table1 contains table2.SQL is:1 //Sub-query2 SelectTable1.id fromtable13 where not exists 4(Select 1 fromtable25

Today, the OPS group's classmates came to me, said the backup pool file description is not displayed, and it is not displayed from the beginning of 20th, the previous file description can be displayed, and 20th of their uploaded backup data is

Primary and Standby Replication configuration1. Create AccountGRANT REPLICATION slave,replication CLIENT on *. *To [e-mail protected]' 172.16.0.% ' identified by ' rep ';2. Configure the main

1.Build a project2.Create first page3.Create an App4.Then add a page to the app4.1Inside the setting Configuration:Add in My_project URLAdd in App1 's URLsCreate viewsAnd thenYou can access it through 127.0.0.1:8000.5.Configuration databaseModifying

I. Master server Master1. Set permissions for usersTo set up users who only allow 192.168.120.27 access:Grant Replication Slave,super,reload on * * to [e-mail protected] identified by ' zhijiatest ';2. The primary database server installation

①. Modifying the%xampp%\phpmyadmin\config.inc.php file[PHP] View plaincopy/* Authentication type and Info */$cfg [' Servers '] [$i] [' auth_type '] = ' config ';$cfg [' Servers '] [$i] [' user '] = ' root ';$cfg [' Servers '] [$i] [' password '] = ';

http://blog.csdn.net/pipisorry/article/details/45072215Storage path for MySQL database filesIf it is compiled and installed on Linux configure, specify--localstatedir=your_data_path;If it is on window: MySQL data is stored by default in "$MySQL

Linux Systems Stop the MySQL process#service mysqld RestartOr#/etc/init.d/killall -term mysqld (not recommended) Start MySQL in safe mode# mysqld_safe–skip-grant-tables &--skip-grant-tables >/dev/null2>&1 & Log in to MySQL#

Want to implement Mysql>drop table like "prefix_%"There are no commands that are directly available, but can be assembled by MySQL syntax, select CONCAT ( " drop TABLE , GROUP_CONCAT (table_name), ) as statement from

MYSQL group submission, mysql submission Group commit is an optimization method for MYSQL to process logs, mainly to solve the problem of frequent disk flushing when writing logs. Group submission is constantly optimized along with the development

Notes for using MySql (1) This article is intended for those who previously engaged in enterprise-level application development, because enterprise-level applications, especially financial enterprises, usually use Oracle or DB2 as