mysql first function

1. Full backup and incremental backup 1.1 full-scale backupFull-volume data is all the data in the database, and a full backup is the backup of all the data in the database.Back Up all libraries:mysqldump -uroot -p123456 -S /data/3306/mysql.sock -F -

String function string comparison function if the result length is greater than the maximum value of the max_allowed_packet system variable, the return value of the string value function is NULL. See section 7.5.2 "Adjust server Parameters ". String

String functionsstring comparison functionsIf the length of the result is greater than the maximum value of the Max_allowed_packet system variable, the return value of the string value function is null. See section 7.5.2, "Tuning server parameters."

For operations on string positions, the first position is marked as 1. ASCII (str) Returns the ASCII code value of the leftmost character of the string str. If Str is an empty string, returns 0. If STR is NULL, returns NULL. Mysql> Select ASCII (' 2

-- Add users and groups [root @ zlmlocal] groupadd [root @ zlmlocal] useradd-gmysql-ssbinnologin-doptmsyqlmysql -- create a directory [root @ zlmlocal] mkdirdatamysqlmysql_3306 {data, l -- Add users and groups[Root @ zlm local] # groupadd [Root @

1. download MySql 1. download MySql Open http://www.mysql.com/downloads/mysql/#downloads download in browser My downloaded version is Red Hat 5 version of http://www.mysql.com/downloads/mirror.php? Id = 407552 Upload the file to the server, or

MySQL obtains the current date and time stamp function bitsCN.com MySQL returns the current date, time, and timestamp. 1.1 obtain the current date + time (date + time) function: now () Mysql> select now (); + ------- + | Now () | + ------- + | 22:2

MySQL performance tuning and Architecture Design-Chapter 1 Performance Design-MySQL Replication and replication Optimization Chapter 1 scalability design-MySQL Replication Preface: MySQL Replication is a unique feature of MySQL. It can completely

MySQL builds a series of multiple instances. The so-called multi-instance is to build and run multiple MySQL instances on one server. each instance uses different service ports and listens through different sockets. physically, each instance has an

Mysql Cluster 1: master-slave replication, using mysql-proxy for load balancing Mysql Cluster There are many mysql Cluster architecture methods, and different architectures are implemented according to different requirements. Simply put, mysql