MySQL

MYSQL Extended Storage EngineHere are a few of the Columnstore engines (all two versions: Community Edition, Commercial Edition):One: TokudbTokudb is a high-performance, transactional-enabled MySQL and MariaDB storage engine. The main feature of

Requirements Description:Case background: In the course of bank transfer, accidents are unavoidable. To avoid unnecessary losses caused by an accident, the transaction is handled in the same way:A account has an existing balance of $1000 and a

A subquery is the nesting of another query statement in a query statement.The query part outside the subquery is referred to as an external query.The subquery must contain parentheses.Any, in, someThe Any keyword must be used with a comparison

[Client]Port = 3306 #客户端端口号socket =/data/3306/mysql.sock #socket file is unique to the Linux/unix system, the user in this environment client connection can not be through the TCP/IP network, and directly using the socket file connection.

--mysql add field and commentSyntax:AlterTabel table NameAdd columnNew field name type (length definition) Comment'comment content to add'Example:Alter TableTbl_user_report_smsAdd columnRpproveVARCHAR( -) COMMENT'the province in which the informant

With regard to the benefits of MySQL indexing, if the correct design and use of the indexed MySQL is a Lamborghini, then no design and use of the index of MySQL is a human tricycle. For tables that do not have an index, a single-table query might be

Convert date format to int using Unix_timestamp ()For example:Select Now (), Unix_timestamp (now ());Now () | Unix_timestamp (now ())2014-11-28 09:54:43 | 1417139683Use From_unixtime () to convert a date from an int type timestampFor example:Select

[Mysqld]Lower_case_table_names=1Datadir=/var/lib/mysqlSocket=/var/lib/mysql/mysql.sockUser=mysql# Disabling Symbolic-links is recommended to prevent assorted security risksSymbolic-links=0#默认存储引擎Default-storage-engine=innodb# #

First, order by generation using Filesort detailed1. First Build tables and indexes/*Timetable*/Create TableCourse (IDint Primary KeyAuto_increment,/*primary key self-increment*/titlevarchar( -) not NULL,/*title*/category_idint not NULL,/*which

Note: Each command in MySQL is followed by a semicolon;1. Display Databasemysql> show databases;+----------+| Database |+----------+| MySQL || Test |+----------+2 rows in Set (0.04 sec)MySQL has just finished installing a database of two databases:

//CREATE database database_name//view database show databases//Select database use database_name//Deleting a database------------------the storage engine and data type in database database_name // View supported storage engines show engines;//query

a prefaceWhat does a varchar (n) n mean, and how many Chinese characters can be stored? is a commonplace problem, and today was a development colleague asked me about this issue, simply write an article to specifically introduce.Two theoretical

Reprint: http://www.cnblogs.com/fnlingnzb-learner/p/5830661.htmlIf MySQL is installed and set up as per the previous method, it is a little easier to connect remotely. I will combine some articles on Baidu to analyze.Local Computer

Recently with MySQL more time, each time under the Computer Management tools to start, feel very troublesome, so the search has been made by the predecessors have done these things, today collection finishing, MySQL start off batch processing feel

The SQL standard defines a Class 4 isolation level, which includes specific rules to define which changes within and outside the transaction are visible and which are not. Low-level isolation levels generally support higher concurrency processing

Transactions: A set of atomic SQL queries. If the database can successfully apply all the statements of the group query to the database, then the reorganization query is executed, otherwise none of the statements will be executed.ACID: atomicity

Database concepts:A database is a warehouse that organizes, stores, and manages data in accordance with its data structure.In real-world applications you will encounter a wide variety of databases such as NoSQL non-relational databases

A prefaceOriginally intends to continue to study InnoDB lock mechanism and complete the second article, when looking for information, I miss the previous csdn's public class "in-depth understanding of MySQL UNDO,REDO,MVCC." Then went to another road,

MySQL as the most critical application data storage Center, how to ensure the reliability and continuity of MySQL service, we have to carefully consider a problem. When Master goes down, how do we ensure that the data is not lost as much as possible,

MySQL cache classification and configuration, MySQL cache classification Configuration   Reading Notes to be supplemented   MySQL cache categoryInnoDB Buffer PoolOperating system cache of InnoDB log files and MyIsAM dataMyIsAM key CacheQuery