MySQL

MySQL Database optimization Framework System1. Hardware-Level optimization2. Operating system level optimization3.MySQL Database Level optimization4.MySQL Security Optimization5. Optimization on the site cluster architecture6.MySQL process, System

One. Official website: https://dev.mysql.com/downloads/mysql/1. Select the corresponding version and download the free install version:2. Do not register account, click "No thanks,just start my download":3. Download to local after direct

One, the system command in MySQLAdded the system command in MySQL 5.x, the simple symbol is \!, so that MySQL can execute the command1 Echo " 12345 " 2 12345Because of a whim, you can use this method to bounce shells.Result OK:Try and select

In MySQL Ops, the research colleague wants to compare the data on the next two different instances and find out the difference, how do you want to compare each field in addition to the primary key?In the first scenario, the write program extracts

Day02One, MySQL indexSecond, MySQL storage engine+++++++++++++++++++++++++++++++++++One, MySQL index1.1 Index Description: Equivalent to "book directory"Page 50001~200 directory informationPhonetic sortingRadical sortStroke sort201~5000 body1.2

SQL database structure + data, if the data is bulk INSERT will be error: 2006-mysql server has gone away.Workaround: Locate the My.ini configuration file in your MySQL directory and add the following

If you have MySQL installedon your computer before you install Xampp , and you have added Windows servicesTwo MySQL conflicts in Windows services when using XAMPPThis means that you have used MySQL on your computer before, and the path and Port are

1 OverviewSemi-synchronous replication refers to a subset of host synchronous replication, and another part of the host asynchronous replicationThe logic of synchronization is that the user writes to the primary server, the primary service is logged

The MySQL slow query log is a log record provided by MySQL, which is used to record SQL statements that execute more than long_query_time seconds. The minimum and default values for Long_query_time are 0 and 10, respectively. It means SQL statements

ObjectiveIt was previously thought that UTF-8 was a universal Character set problem solution until recently encountered with this problem. Recently in the Sina Weibo crawler, in the library when it was found that as long as the emoji expression, it

1 OverviewThis article will cover the following six types of MySQL logs related conceptsQuery log: General_logSlow query log: log_slow_queriesError log: Log_error, log_warningsBinary log: BinlogRelay log: Relay_logTransaction log: Innodb_log2 Query

Check to see if the MySQL database federated engine is turned on.Show engines;If the federated is not turned on, add federated to mysqld in MySQL configuration file my.cnf. The user who adds the remote Access database in the remote database creates

Previously done a multi-instance MySQL on a single machine, this time separate to do, using two hosts.The host addresses used here are:master:192.168.214.135slave:192.168.214.128The two hosts already have MySQL installed, but two database data are

SELECT Group_concat (REPLACE (Path, '/', ', ')) as path from Department b WHERE Department_type = 1Execution Result:Sql:Select DISTINCT Substring_index (Substring_index (A.path, ', ', b.help_topic_id + 1), ', ', -1) from (select Group_ CONCAT

MySQL is very popular for its free and sufficient performance, of course, for small domestic companies, and even large companies if the copyright is thin, dare to take risks, just install a SQL Server, DB2, Oracle can be. For SQL Server database,

Data typetruncate t1 (delete table) # unsigned type ALTER TABLE t1 modify ID tinyint unsigned (table has value, cannot be changed directly) desc T1========================================tinyint[(m)] [unsigned] [zerofill] small integer, data type

First, lamp architecture introduction:linux+ Apache (httpd) + MySQL + PHPOperating system + Extranet service Software + storage Software + scripting language (developed by C)PHP websiteThree characters can be installed on a machine, can also be

工欲善其事 its prerequisite" If you meet God on the road, God will be cut," said half. "MySQL Index classification (using the B-tree structure by default)In a database table, indexing a field can greatly improve query speed. By leveraging these indexes,

Mybatis + mysql use the stored procedure to generate the serial number implementation code, mybatis serial number Use stored procedures to enable transactions during database operations to avoid data duplication during concurrent operations Create

Mysql5.7.20 installation and configuration method graphic tutorial (mac ), How to install and configure mysql5.7.20 1. Official Website: https://dev.mysql.com/downloads/mysql/download We strongly recommend that you download the dmg file. After