MySQL is a basic manager of data free. He is very much used in the free projects and industrial environment.
CharacteristicsMySQL is a waiter of relational databases SQL developed in a preoccupation with high performances. It is multi-thread, multi-user. It is a Free software developed under double license according to the use which is made by it: in a free product (open-source) or in a product owner. In this last case, the license is paying, if not it is free.
Supported systemsMySQL functions on many different platforms, including AIX, BSDi, FreeBSD, HP-UX, Linux, Mac OS X, NetWare, NetBSD, OpenBSD, OS/2 Warp, SGI Irix, Solaris, SunOS, SCO OpenServer, SCO UnixWare, Tru64 Unix, Windows 95,98, NT, 2000, XP and Vista.
The databases are accessible by using the Computer programming languages C, C++, C#, Delphi/Kylix, Eiffel, Java, Perl, Python, Ruby and Tcl; a API specific is available for each one of them. An interface ODBC called MyODBC is also available. In Java, MySQL can be used in a transparent way with the standard JDO.
UseMySQL belongs to the quartet LAMP: Linux, Apache, MySQL, . The /MySQL couple is very much used by the Web sites and is proposed by the majority of the shelterers.
Wikipédia as well as many other companies and services such as YouTube or Adobe use MySQL.
DenominationMySQL is the work of a Swedish company, MySQL AB, founded by David Axmark, Allan Larsson and Michael Widenius.
Le name MySQL comes from their practice to prefix by “My” most of their files, libraries and tools. The girl of Michael Widenius was called “My”.
The name of the logo of MySQL (the Dolphin) Sakila, was chosen by the creators of MySQL on the basis of contest. He was proposed by Ambrose Twebaze, developer of the Swaziland. According to Ambrose, the name Sakila draws its origins of the Siswati, the local language of Swaziland.
HistoryThe first version of MySQL appeared the May 23rd 1995.
It was initially created for a personal use starting from MSQL while being based on the low-level language ISAM which they found too slow and too rigid. They created a new interface SQL by keeping same the API as MSQL.
MySQL passed in license LPG starting from version 3.23.19 (June 2000)
- Version 4.0: first version in stable October 2001, since March 2003
- Version 4.1: first version in April 2003, stable since October 2004
- Version 5.0: first version in December 2003, stable since October 2005
- Version 5.1: first version in November 2005, Release Candidate distributed since September 2007
- Version 5.2: distributed in preview (addition of the new engine of storage Falcon ) in February 2007, this line was then famous 6.0
- Version 6.0: first version alpha in April 2007
Basic engines of data included
One of specificities of MySQL is to be able to manage several engines within one only base. Each table can use a different engine within a base. This in order to optimize the use of each table.
Here various engines that MySQL manages:
MyISAM : engine owing to lack of MySQL. It is simplest to use and implement. It uses several files which grow as the base grows bigger. It does not support the transactions, nor the foreign keys.
- InnoDB : engine created and maintained by InnoBase (Repurchased by Oracle on October 7th, 2005). It manages the key foreign transactions and . N the other hand, the bases which use it occupy much more space on the disc.
- MERGE : engine made to amalgamate several tables which must be identical.
- FILE : engine adapted to the filing of data. The lines are compressed progressively of their insertion.
- MEMORY (HEAP) : engine where the tables are stored only in memory.
- CSV : using engine of the textual files (with the format CSV) like storage.
- BLACKHOLE : engine taking delivery of the data, transferring them but not storing them. It can be used as repeater or like filters data.
- ISAM : engine of origin of MySQL, now obsolete and replaced by MyISAM. It remained for reasons of compatibility.
- NDB (only in the version MaxDB): NR etwork D ATA B ESA . Basic engine of data network managing the clustering.
ClusteringMySQL proposes a solution of clustering since its version 4.1 thanks to the engine of storage NDB. Its structure bases on the Réplication data, i.e. that each node of the bunch will have a copy of the base locally.
A repartissor of load will deal with making the request to the node charged with the bunch, one thus needs at least three machines to establish a solution of clustering MySQL. If one of the nodes of the bunch does not answer any more, the repartissor of load will not send any more requests towards this one, the bunch will be able to always function as long as at least a node of the bunch will be always in operating condition.
On the level of the performances, the processing time of the operations of recovery of data will be reduced but during a modification of the data (a request UPDATE for example), this one will be done on each node of the bunch, it thus does not have there no profit on this level, moreover, since the base is on each element, one needs N time the number of disk space necessary to store the data on the whole (N representing the number of nodes). The addition of a new node can be done without needing Re-partitionner the base.
This solution thus adapts to a Cluster having a small number of nodes and when the availability and the data security are a critical problem.
This technique of replication of the data is also used on PostgreSQL with PgCluster.
Tools associated with MySQL
Products of MySQL AB
- MySQL administrator, software of administration of databases.
- MySQL Query Browser; graphical interface to maintain the base and to make requests there.
- MySQL Workbench, software of design and basic modeling of data.
- MySQL Toolkit Migration, software allowing to migrate your database towards your MySQL database.
- PhpMyAdmin, a tool of administration of MySQL databases writes in.
- eSKUeL, interface WEB in administration of a MySQL base.
- XAMPP, a total solution Web (Apache, MySQL, Mercury,) under license GNU General Public License as well for Linux as for Windows
- MysqlFront, software to create and publish tables SQL (Now prohibited by MySql). It has several clones heidisql and SQLyog.
- Official site
- French-speaking Web site of MySQL
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