What are common MySQL skills?

The following articles mainly introduce common MySQL skills. We will mainly introduce seven practical application skills. If you are interested in these seven common MySQL skills, you can browse the following articles and hope to bring you some help in learning.

1) One of the common MySQL skills, it is best to subscribe to user permission management at the DB or Table level. do not enable global permissions easily;

2) Common MySQL Skills 2: grant and revoke for user authorization and permission acquisition;

 
 

  
  
MySQL> grant select on db.* to user@host identified by ‘passwd’;  
  
  
MySQL> revoke all on db.* from user@host;  
  
  
MySQL> flush privileges; 
 
 

Note: After changing user permissions, run flush to make the change take effect;

3) Common MySQL skills 3: several important commands for viewing the server running status;

Show status; displays the running status of the system.

Show variables; displays system running parameter settings and Environment variables

Show processlist; displays the existing access connections;

For the master slave system, there are also: show master/slave status;

4) MySQL common skills 4. Set the maximum number of concurrent response connections and the maximum number of waiting connections in the response queue to be related to the specific operating system) and the idle connection timeout time

Max connections

View: MySQL> show variables like 'max _ connections ';

Settings: MySQL> set global max_connections = 200;

The default value is 100. If it is set to 0, no restriction is imposed;

Transient concurrent waiting connections

View: MySQL> show variables like 'back _ log ';

Set: MySQL> set global back_log = 200;

The default value is 50;

Idle connection timeout

MySQL> set wait_timeout = 3600;

The default value is 28800, which is 8 hours, in seconds;

5) MySQL common skills 5. Optimize table fragmentation)

If a table with a large data volume is modified in large quantities, you can run the following command:

MySQL> optimize table table_name;

To achieve the purpose of fragment;

6) Tips for MySQL 6. Use MySQLhotcopy for Hot Backup of database files

/Home/MySQL/bin/MySQLhotcopy db_name [./table_regex/] [new_db_name | direc release]

Example:

/Home/MySQL/bin/MySQLhotcopy-u root-p 'xxxx' test./^ tt $ /./

Note: MySQLhotcopy is a perl program and must be supported by the DBI and DBD perl modules.

7) Common MySQL skills 7. error logs and binlogs

The error log is generally in the data directory, for example:

Var/. err

Binlog can record all operation records in the database. It is enabled using the log-bin option in my. cnf. If it is commented out, the binlog content can be viewed using the following command:

 
 

  
  
MySQLbinlog [options] log-files 
 
 

Appendix permission Name and description list

 
 

  
  
Privilege  
  
  
Meaning  
  
  
ALL [PRIVILEGES]  
  
  
Sets all simple privileges except GRANT OPTION  
  
  
ALTER  
  
  
Allows use of ALTER TABLE  
  
  
CREATE  
  
  
Allows use of CREATE TABLE  
  
  
CREATE TEMPORARY TABLES  
  
  
Allows use of CREATE TEMPORARY TABLE  
  
  
DELETE  
  
  
Allows use of DELETE  
  
  
DROP  
  
  
Allows use of DROP TABLE  
  
  
EXECUTE  
  
  
Not implemented  
  
  
FILE  
  
  
Allows use of SELECT … INTO OUTFILE and LOAD DATA INFILE  
  
  
INDEX  
  
  
Allows use of CREATE INDEX and DROP INDEX  
  
  
INSERT  
  
  
Allows use of INSERT  
  
  
LOCK TABLES  
  
  
Allows use of LOCK TABLES on tables for which you have the SELECT privilege  
  
  
PROCESS  
  
  
Allows use of SHOW FULL PROCESSLIST  
  
  
REFERENCES  
  
  
Not implemented  
  
  
RELOAD  
  
  
Allows use of FLUSH  
  
  
REPLICATION CLIENT  
  
  
Allows the user to ask where slave or master servers are  
  
  
REPLICATION SLAVE  
  
  
Needed for replication slaves (to read binary log events from the master)  
  
  
SELECT  
  
  
Allows use of SELECT  
  
  
SHOW DATABASES  
  
  
SHOW DATABASES shows all databases  
  
  
SHUTDOWN  
  
  
Allows use of MySQLadmin shutdown  
  
  
SUPER  
  
  
Allows use of CHANGE MASTER, KILL, PURGE MASTER LOGS, and SET GLOBAL statements, 
  
  
the MySQLadmin debug command; allows you to connect (once) even if max_connections is reached  
  
  
UPDATE  
  
  
Allows use of UPDATE  
  
  
USAGE  
  
  
Synonym for “no privileges”  
  
  
GRANT OPTION  
  
  
Allows privileges to be granted  
 
 

The above content is an introduction to common MySQL skills. I hope you will get something better.