MySQL

In the actual production environment, if the read and write to the database in the same database server operation, whether it is security, high availability, or high concurrency and other aspects are completely unable to meet the actual demand,

1. Index classification1. General Index2. Unique index3. Primary KEY index4. Foreign KEY Index2. Normal index1. Rules of Use1. You can have more than one index field in a table2, the value of the field can be duplicated, or it can be a null value3.

1. Copy table structure and data to new table CREATE table new Table select * from old table 2. Only copy table structure to new Table Method 1: (Low version of MySQL is not supported, mysql4.0.25 not supported, MYSQL5 already supported)

172.16.26.33--mysql-socket=/tmp/mysql3306.sockSysbench three steps to load MySQL: Prepare------cleanupWe're all using Sysbench's own LUA script to test MySQL.# #1. Test MySQL using Oltp_read_write.lua script to test MySQL prep stage:

1, the table's primary key, the foreign key must have the index;2, the data volume of more than 300 of the table should be indexed;3. Tables that are often connected to other tables should be indexed on the connection field;4. Fields that often

MySQL's common hintFor friends who often use Oracle, it is possible to know that Oracle has a wide variety of hint features and provides many ways to optimize SQL statements. Similarly, in MySQL, there are similar hint functions. Here are some

1.mysql services are provided through the MYSQLD processWe can simply double-click Mysqld.exe or enter mysqld in cmd mode. Both operations create mysqld processes in the backgroundAfter we have created the mysqld.exe process, we can log in to MySQL.2

In the previous article, we introduced the MySQL master-slave building based on Docker, and the construction process of a master multi-slave is to repeat a master-one from the library configuration process, it is necessary to pay attention to ensure

Some optimizations need to be made when the table has a large amount of data:1. Index the query criteria field;2. The index field cannot have a null value, and the index is invalidated when a null value occurs;3. The query statement appears not

Unpack the package, install CMake[[email protected] ~]# lscmake-2.8.12.2-4.el6.x86_64.rpm mysql-5.7.17 mysql-boost-5.7.17.tar.gz[email protected] ~]# Yum install-y cmake-2.8.12.2-4.el6.x86_64.rpmInstall dependencies First[email protected] mysql-5.7.1

Planning1. Download binary Packagehttps://downloads.mariadb.org/mariadb/10.2.16/2. Clean Logical Volume LVM3. New logical volumes mounted to/data4,/data/mysql directory Storage database5. Unzip to the installation directory to view the built-in

MySQL Replace statement introduction　MySQL's replace statement is a MySQL extension to the SQL standard statement.Official definition: REPLACE works exactly like INSERT, except this if an old row in the table have the same value as a new row for a

Encounter a problem, online find a lot of information can not solve their own curve to solve the national salvation, record, if you have a better way to welcome the message.First I created a table on the MySQL database with the datetime type of the

In MySQL, we can obtain information about how MySQL executes the SELECT statement through the EXPLAIN command, including the order in which the table joins and joins during the SELECT statement execution.Each column of the results of the EXPLAIN

The previous article describes the order in which Oracle's select syntax is executed, which describes the order in which MySQL's select syntax is executed. MySQL's select syntax is executed in the same order as Oracle, only adding MySQL's unique

The debugging of the lock is divided into two parts, one is the debugging of the server level lock. The second is the debug of the lock at the storage engine levelDebugging for server-level locks:The types of server-level locks are table locks,

EmployeeThe table contains all employee information, each employee has its corresponding ID, salary, and department ID.+----+-------+--------+--------------+| Id | Name | Salary | DepartmentID |+----+-------+--------+--------------+| 1 | Joe | 70

The SQL language is divided into four categories: Data Query Language DQL, Data manipulation language DML, data definition language DDL, Data Control Language DCL.1. Data Query Language DQL The DQL basic structure of the data query language

Usage scenarios:In daily use, the database system is often used, in which the Internet uses the most types of databases to be the MySQL database, but the use of this database is not only a single database for individual users (root), will be

SELECT * from stu st,course co,score sc where st.sid = sc.sid and sc.cid = co.cidIf we are going to give SID a constraint, that is, the SID in the two tables should correspond, so we're going to add the foreign keyScore Association Stu:At this point,