mysql pocket reference

is:0.3 million data. It is feasible to use the table sharding method. If it exceeds 0.3 million, it will slow down and you cannot bear it! Of course, if you use the sub-table + me method, it is absolutely perfect. However, after using this method, it can be perfectly solved without table sharding!The answer is: Composite Index! When I designed a mysql index, I accidentally found that the index name can be any one, and several fields can be selected.

MySql Error Based Injection Reference[Mysql brute-force injection reference] Author: Pnig0s1992Blog: http://pnig0s1992.blog.51cto.com/TeAm: http://www.FreeBuf.com/Mysql5.0.91 passed the test. Most versions of MySQL 5 + can be tested successfully.If name_const () is used in a

MySQL official reference manual Chinese version: http://dev.mysql.com/doc/refman/5.1/zh/index.htmlTwo analysis solutions for MySQL slow query: http://www.bitscn.com/pdb/mysql/201006/186917.htmlMySQL slow query log: http://blog.chinaunix.net/u/9817/showart_1093402.html Common commands Backup and recoveryBackup Database

It is said that this is the master optimized MySQL for your reference, where the number of connections: max_connections=1500 can be based on server performance changes. #set-variable=connect_timeout=5 #set-variable=wait_timeout=5 Recommended enabling, heavy servers can reduce the duration of the connection properly [Mysqld]Basedir=d:/mysql#bind-address=ipDatad

Label:The project has the use of MySQL database, EF Do data layer, found that there is a table saved always error. The error message is as follows System.NullReferenceException: Object reference not set to an instance of an object.In MYSQL.DATA.ENTITY.LISTFRAGMENT.WRITESQL (StringBuilder sql)In MYSQL.DATA.ENTITY.SELECTSTATEMENT.WRITESQL (StringBuilder sql)In MYSQL.DATA.ENTITY.INSERTSTATEMENT.WRITESQL

Mysql_config,jsConst Mysqlconfig ={ host:' localhost ', User:' root ', password:' 123456 ' , ' 3306 ', database:' user '=mysqlconfig;Test.jsConst MySQL = require (' MySQL ');varMysqlconfig=require ('./mysql_config ')). Mysqlconfig;vardb =mysql.createconnection (mysqlconfig);varsql = ' SELECT * from name ';//Check the articlevarUseraddsql = ' INSERT into name ' (id,un

There was a problem when the data source configuration was added with the Encoding conversion format:The reference to entity "characterencoding" must end with the '; ' delimiterThis error is the problem of setting the URL of the data source link in Context.xmlThe correct is as follows:This is probably determined by the encoding rules in the XML file to be transformed.The following types of characters are escaped in the XML file:Less than signgt;>Great

Tags: des style blog http color data ar div1. MySQL 5.1 Reference Manual2. Basic Tutorials3, commonly used examples into the following:1 Connect to the database:MySQL-H Host Address-u user name-P user password2 Prompt for database:MySQL> 3 Exit Database:Exit(carriage return)4Display database: show databases;5CREATE database: Create library name;6 Select database: Usedatabase name;7Show tables in the databas

Label:Currently, Haproxy has been used to load balance the MSSQL read library, which runs well in the production environment.However, this scenario has drawbacks: the client needs to choose whether to use a read library or a write library. This is still not convenient, if you can implement automatic routing is better, that is, let Haproxy automatically choose to send the request to read library or write library.I plan to write a haproxy module that implements the automatic routing function in th

attention to updating the problem.4 for some simple objects, use value directly as the building. such as IP address, etc.5) Reference by Primary/unique KEY. MySQL can optimize this operation, for example: Java codeSelect City_nameFrom City,statewhere State_id=state.id and state.code= ' CA ' "converted to" select City_name from city where state_id=12 2.1.2 Data typeOne of the most basic optimizations is t

-index-usage tool to check and remove low-frequency indexes;5, the regular collection slow query log, with the Pt-query-digest tool analysis, can be combined with anemometer system slow query management in order to analyze slow query and follow-up optimization work;6, can use Pt-kill kill long time of SQL request, Percona version has an option innodb_kill_idle_transaction also can realize this function;7, using Pt-online-schema-change to complete the large table online DDL requirements;8, regula

. Periodically use the Pt-index-usage tool to check and remove low-frequency indexes;5, the regular collection slow query log, with the Pt-query-digest tool analysis, can be combined with anemometer system slow query management in order to analyze slow query and follow-up optimization work;6, can use Pt-kill kill long time of SQL request, Percona version has an option innodb_kill_idle_transaction also can realize this function;7, using Pt-online-schema-change to complete the large table online D

. Because PXC has write enlargement and short board effect, the concurrency efficiency will have a large loss, similar to the semi sync replication mechanism.Other high-availability scenarios Based on NDB Cluster, there are still many defects and limitations in NDB, and it is not recommended to use in production environment. Based on shared storage, on the one hand, the need for a less poor storage device, the other shared storage can also become a new single point, unless the use o

Mysql| reference This appendix describes each column type provided by MySQL. See chapter 2nd for detailed instructions on taking advantage of each type. Unless otherwise stated, the listed types are already available in MySQL3.21.0. A description of the type name is given in the following conventions: square brackets ([]) optional information. M Maximum display w

Mysql|sql Grammar | reference | data | database | Grammar reference one, data definition DDL (data definition Language) Data-setting language refers to the language defined in the format and form of data, he is the first to be set up when each database is to be established, what is the form of data, the form of a field key, tables and tables of the relationship b

student's school number, name and average score;Select Student.sid,student.sname,b.numname from (select Student_id,avg (num) as Numname from score GROUP by student_id HAVI NG AVG (num) >60) as Bleft JOIN student on B.student_id=student.sid4, inquiry all students of the school number, name, number of courses selected, total;SELECT Student_id,student.sname,count (course_id), SUM (num) from score left JOIN student on Score.student_id=student.sid GROUP by student_id5, inquire the surname "Li" the n