MySQL

Using mysqldumpslow to analyze and execute slow SQL statement mysqldumpslow-s c-t 10/var/log/mysql/mysql-slow.log www.2cto.com MySQL database has a function that can be recorded in the form of logs to run Ratio slow SQL statement, this function is

The efficiency of using indexes in Mysql for instance testing increases the efficiency of DATABASE creation: [SQL] create database 'SQL _ learn_db'; www.2cto.com creates a Table: [SQL] Create Table: create table 'persons '('id' int (11) not null

Considerations and advantages of using Mysql Merge tables in Mysql databases, Mysql Merge tables are somewhat similar to views. Next let's take a look at the advantages of Mysql Merge tables. Advantages of Mysql Merge table: www.2cto.com A: Separate

In linux, how does one implement daily automatic backup of mysql Databases and create a backup Folder: mkdir mysql_data_bak script file: touch autobackupmysql. sh www.2cto.com open the file vi autobackupmysql. sh adds the following content to the

In mysqldump, when a trigger is used to convert a myisam table to innodb, the schema is first exported and then only data is exported. For example: www.2cto.com mysqldump -- no-data databasename> schema. SQL output data: mysqldump -- no-create-info

The remote mysql client cannot be connected. By default, the installed mysql cannot be accessed remotely, mainly due to the following two reasons: www.2cto.com 1. the mysqld service does not monitor IP addresses that can be remotely accessed.

A friend of www.2cto.com asked a question today. The original Article is: mysql5.1, MyISAM table, select count (*) as total FROM m_bff WHERE from_uid = '000000' AND isdeleted = 0. From_uid has an index. The speed of executing this sentence for the

MySQL query and Analysis and Optimization Show www.2cto.com show status -- display status information (Extended show status like 'xxx') show variables -- display system variables (Extended show variables like 'xxx ') show engine innodb status --

MySQL YEARWEEK function and query data of this weekMySQL YEARWEEK is a function used to obtain the year and week number. The function form is YEARWEEK (date [, mode]).For example, SundayWww.2cto.comSelect yearweek ('2017-3-14 ') returns 11Select

CREATE a partition TABLE www.2cto.com create table 'table name' ('equipmentid' char (17) not null, 'bubuteid' char (4) not null, 'value' varchar (20) not null, 'collecttime' datetime not null) ENGINE = InnoDB (applicable to most engines and can be

SELECT * FROM 'table' WHERE id> = (SELECT floor (RAND () * (select max (id) FROM 'table '))) order by id LIMIT 1; finally, complete the statement and add the MIN (id) judgment. At the beginning of the test, because I did not add the MIN (id)

Innobackupex's backup Parameter Parsing A. Generally, innobackupex is directly used for data backup because it can back up InnoDB and MyISAM engine tables at the same time. Note that the datadir parameter in my. cnf must be specified. xtrabackup_55

Description of the foreign key constraint of Mysql on cascade for the sub-table: if the candidate key cannot be found in the parent table, the meaning of the foreign key constraint of insert/update on the sub-table to the parent table is not allowed:

Mysql Stored Procedure experiencesQuestion: What is the significance of the mysql stored procedure?The stored procedure is compiled only when it is created. You do not need to re-compile the stored procedure every time you execute it. Generally, the

The innodb index concept summarizes the index concepts of innodb. For more information, see innodb index classification: clustered index (clustered index) 1. Create a clustered index based on the primary key when a primary key is available. 2) if

Batch Update: obtains the values of the associated fields from another table to UPDATE the joinCount value of the current table. Update EventGroup g SET joinCount = (SELECT B. counts FROM (SELECT eventGroupId, SUM (1) AS counts FROM EventGroupMember

The storage engine for database configuration optimization is mainly innodb, 2 GB memory is planned for Mysql to run the configuration file. Java code skip-external-locking key_buffer_size = 16 M bytes = 1 M table_open_cache = 512 sort_buffer_size =

General table merging Stored PROCEDURE circular variables and character connection Java code mysql> DELIMITER $ mysql> drop PROCEDURE sp_test_switch $ Query OK, 0 rows affected (0.01 sec) mysql> create procedure sp_test_switch ()-> BEGIN-> declare a

How to smoothly "restart" mysql note that the restart in the title is a mysql server in the production environment with quotation marks. Generally, it is necessary to avoid restarting as much as possible, but it is time-consuming to face the slow

Mysql master slave yum uninstall selinux yum remove selinux *-y involved in the software license mysql-5.1.40.tar.gz put the above software package under/software/mysql Unzip a unzip, install mysqltar zxvf mysql-5.1.40.tar.gzcd. /configure -- prefix