MySQL

Brief introduction1 · Index and classification2 · Create and view indexes3 · The concept and characteristics of the transaction4 • Operation of the transaction5 · Summary Expansion : Before you begin to understand the index, learn to

# database Layer Permission record locationTable-level permissions are recorded in the Mysql.tables_priv table.([email protected]) [mysql]> ([email protected]) [mysql]> desc tables_priv;+-------------+--------------------------------- ---------------

I. OverviewThe previous section describes many of the database optimization measures, but in the actual production environment, due to the performance limitations of the database server itself, it is necessary to optimize the application of the

Reference Link: https://www.cnblogs.com/ThinkVenus/p/7670722.htmlAfter entering the database, you can only see information_schema/test these two libraries, the other databases are not visible, this is a problem with permissions.Turn off MySQL,

First, the role of MysqlreportFor MySQL configuration optimization, you must first identify the MySQL performance bottleneck, and the show status output report is the reference data used to calculate the performance bottleneck. Mysqlreport is not as

DQLBasic Query field (column) control 1) Query all columns: SELECT * from table name ; "*" means querying all columns 2) Query the specified column: Select column 1, column 2, column N from table name ; 3) complete duplicate records

First: Chapter One1: Using TransactionsTransaction ; Select * from T1; commit;2: View transaction statusMysql>Show variables like 'autocommit';+---------------+-------+|Variable_name|Value|+---------------+-------+|Autocommit| on |+-------------

Common commands1. Displays the list of databases in the current database server: MySQL> SHOW DATABASES;2. Establish the database: MySQL>CREATEdatabase name;3. Set up the data sheet:MySQL> use library name; MySQL>CREATETABLEVARCHAR(1CHAR);4.

Mysql> grant permissions 1, permissions 2,... Permission n on the database name. Table name to User name @ user address identified by ' connection password ';Permissions 1, Permissions 2,... Permission n represents 14 permissions, such as

1: See if a MySQL version is availablerpm -qa | grep mysqlDelete MySQL account and user groupDelete/ETC/MY.CNF2: Some words are deletedrpm -e mysql-......Orcommen]# rpm -e --nodeps mysql-......3: Download rpmwget

1. First log on to Linux with Administrator privileges;2. Enter: VI/ETC/MY.CNF enter. Then press "I" keyboard, enter in the last line of this file: Skip-grant-tables then press ESC, then enter ": Wq" to save and exit;3. Restart the MySQL service

There are two ways of MySQL: floating-point and fixed-point. Floating-point numbers include float (single-precision) and double (double-precision), while the number of points is only a decimal representation.Fixed-point numbers are stored as strings

MySQL database common operation one, MySQL General Command 1) displays the current database version number and date.MariaDB [(none)]> select version(),current_date();+----------------+----------------+| version() | current_date() |+-------------

Redo log (redo log)Preface: The difference between the bin log and the InnoDB log file in MySQL has been unclear, and there is always a question in the mind binlog log files can be used forLog backups of the database have been restored, and a redo

Creating an instance: Create TABLE hash_emp ( tid int, tname char (255) ) PARTITION by HASH (TID) partitions 8;View:Select Partition_name,partition_expression,partition_description,table_rows from Information_schema.partitions

Official Document Address: https://dev.mysql.com/doc/refman/5.7/en/binary-installation.htmlStart installation 1, download MySQL binary package# cd/usr/local/wget https://dev.mysql.com/get/downloads/mysql-5.7/

Get a new environment, need to find the relevant configuration, I have a way to relatively fast copy a set of environment.To modify the machine configuration:Virsh related several commands, has been completed, follow-up I re-organize to add ...To

1 , group replication server Settings[Mysqld]# Server ConfigurationDatadir=/data/s1basedir=/mysql-8.0/port=24801Socket=/s1.sockAttentionThe use of non-default port 24801 is because in this tutorial, three server instances use the same host name.

download MySQL Official website Download MYSQL5.7.21 version, link address https://www.mysql.com/downloads/. Download the flowchart as follows: Enter the official dot click community, download the community version. Locate the MySQL Community Server

Synchronize data from the library on the main library (to have other database servers automatically synchronize data on the data server that is currently being accessed)Structure type of master-slave synchronization1 primary------>1 from (common)