MySQL occurs as multithreaded, multi-user, SQL (Structured Query Language) Database Management System (DBMS) with an guessed six million installations. MySQL AB makes MySQL available as open source software / free software under the GNU General Public License (GPL), but it besides sell it under traditional commercial message licensing arrangements for instances in which a arranged utilize is incompatible sustaining utilise of the GPL.

Unlike projects like Apache, where a software package is developed by a public community, & is in essence non owned by anyone, MySQL is owned & sponsored by one for-benefit house, the Swedish company MySQL AB. A company develops & maintains the system, selling support and service contracts, when well as commercially-licensed copies of MySQL, and using population 100% across a world world health organization operate together via the Internet. 2 Swedes & the Finn founded MySQL AB: David Axmark, Allan Larsson and Michael "Monty" Widenius.

Programming languages

There are APIs available that allow applications written in many Programming languages to access MySQL databases, including: C, C++, C#, Eiffel, Smalltalk, Java (with the native Java driver implementation), Lisp, Perl, PHP, Python, Ruby, REALbasic and Tcl; each one utilizes the specific API. An ODBC interface called MyODBC allows additional programing language that trend lines a ODBC interface to communicate with the MySQL database. MySQL is mostly implemented within ANSI C, and, that existence the most common "lingua franca" for rules libraries, tends to apply that when its "native" language.

Uses
MySQL is popular for web applications like Wikipedia and PHP-Nuke and acts as a database component of LAMP. A popularity as a web application is closely attached to the popularity of PHP, which is often combined using MySQL & nicknamed a Dynamic Duo. These are easily to call for numbers of information that combine them within websites & books (PHP & MySQL for Dummies, PHP & MySQL Bible, Beginning PHP & MySQL, etc.) A claim processed around numerous books is that MySQL is more easygoing to view & utilize than numbers of more database applications. An lesson from either a Dummies book is you could quit MySQL using an perceptible command of either exit or even quit.

Administration
To administer MySQL databases professional people may utilize a involved comm&-line convienence (commands: mysql and mysqladmin). Likewise downloadable from either a MySQL places come GUI administration tools: [http://mysql.com/products/tools/administrator MySQL Administrator] & [http://mysql.com/products/tools/query-browser MySQL Query Browser].

The far flung & popular choice, written around PHP, is the open source web application phpMyAdmin.

Program specifications
Platforms
MySQL works in numerous different platforms—including AIX, BSDi, FreeBSD, HP-UX, Linux, Mac OS X, NetBSD, Netware, OpenBSD, OS/2 Warp, QNX, SGI IRIX, Solaris, SunOS, SCO OpenServer, SCO UnixWare, Tru64, Windows 95, Windows 98, Windows NT, Windows 2000, Windows XP and more recent versions of Windows. The port of MySQL to OpenVMS is available [http://www.pi-net.dyndns.org/anonymous/kits/ here].

The latest production version
When of 2005, MySQL offers production version 4.One.Fourteen. It includes a resulting features: A wide subset of ANSI SQL 99, also when extensions Cross-platform support Independent storage engines (MyISAM for read speed, InnoDB for transactions & referential integrity) Transactions, including savepoints SSL support Query caching Sub-SELECTs (or nested SELECTs) Replication by using of these master by the buckle down, several slaves by the master Full-text indexing and searching applying MyISAM engine Embedded database library Full Unicode support ACID compliance using InnoDB engine Shared-nothing clustering across MySQL Cluster

It doesn't include a resulting features: Stored procedures Triggers Cursors Views Multi-master replication

Future releases
MySQL Five.Nought, which is today in the Release Candidate phase, contains trend lines for the ensuing features: Stored procedures Views Cursors True VARCHAR support Triggers INFORMATION_SCHEMA Strict mode Better optimizer X/Open XA distributed transaction processing (DTP) trend lines by owning deuce phase commit

MySQL Five.Single might virtually all probably contain trend lines for: Partitioning Online backup for all storage engines Foreign key support for all storage engines Fail-safe replication Column-level constraints

Distinguishing features
A as punishment features come implemented by MySQL but not by another RDBMSes:

Multiple storage engines (MyISAM, InnoDB, BDB, memory/heap, cluster in Four.x), allowing smart shoppers explore a 1 which is virtually all effectual for every table in the application. Commit grouping, gathering multiple dealing from either multiple modems together to increase a total of commits by the 2nd.

Source Code Specifics

MySQL is written inside the mixture of C and C++. A SQL parser is lex/yacc. a document describing a select few of a internal structures of the code & the ignore guidelines is available from either the MySQL internet site.

Support
Via MySQL Network MySQL AB offers trend lines itself, including 24/7 Thirty microscopic response instance, by owning a trend lines team getting directly access to the developers when necessary to address problems. Additionally it hosts forums & mailing lists & employees & more users come typically available within many IRC trend lines providing assistance.

Licensing
Each the MySQL server softwcome program itself & a client libraries are distributed under a dual-licensing format. Users could buy a GNU General Public License [http://www.mysql.com/products/licensing/opensource-license.html], or it might see the commercial license.

A select few users own independently continued to evolve an earliest version of a client libraries, which was distributed under the less-restrictive Lesser General Public License. [http://packages.debian.org/testing/libs/libmysqlclient10]

Pronunciation
"MySQL" is officially pronounced when "My Ess Que Ell" [http://dev.mysql.com/doc/mysql/en/What-is.html#IDX25]. Even so, a company doesn't mind whenever others utilize either a "My sequel" form or even more local variations whenever it is favorite per speaker.

A "My" part of a title comes from either the title of Monty's tyke, spelt "My" however pronounced in the local language when "Me".

A "SQL" part utilizes a fully spelled-out pronunciation of a acronym, S-Q-L, non the "sequel" pronunciation, which conflicts by having a earliest IBM database of that title.[http://www.faqs.org/docs/ppbook/c1164.htm]

A Swedish (MySQL AB occurs as Swedish company) word "Myskväll" (cozy evening, or The's evening, "Mys kväll") is pronounced in kind however this may exist as the coincidence. All the same this pronouncation is quite common within Sweden.

Criticisms of MySQL
Early versions of MySQL involved pack standard RDBMS features, & a todays production version however lacks numbers of properties noticed inside more SQL RDBMSs. This has led occasionally database experts, such as Chris Date and Fabian Pascal, to criticize MySQL as falling short of being an RDBMS.

Numbers of of a early criticisms use at times been remedied inside late versions of the package, including the deficiency of dealing & relational integrity constraints. Which are actually features necessary to trend lines a "ACID properties" for even relational databases, which allow the DBMS to assure that client applications just can't interfere by using 1 an additional or insert inconsistent values. [http://www.service-architecture.com/database/articles/acid_properties.html] More criticisms include MySQL's moving average convergence divergence from either a SQL standard on the subject of coarse of action of Void values & default values. Its treating of dates allows storing the date sustaining the day beyond the last judgement of a year by having less than 31 years, & arithmetic operations come vulnerable to either whole number overflow or even swimming point truncation ([http://sql-info.de/mysql/gotchas.html]). These values come treated based on data from a SQL standards within MySQL version Quint through the apply of favorite [http://dev.mysql.com/doc/mysql/en/server-sql-mode.html SQL Modes].

Earliest versions of the MySQL manual involved claims that certain requirement missing features were useless or harmful, & that users were better bump off forgoing the two. 1 segment, entitled "Reasons NOT to use Foreign Keys constraints" (set), advised users that relational-integrity checking was hard to have & complicated a database application, & that its single utile purpose was to allow client computer software to diagram the relationships between database tables. [http://sunsite.univie.ac.at/textbooks/mysql/manual.html#Broken_Foreign_KEY] the second subdivision claimed that a DBMS lacking dealings could provide when dependable of information-integrity assurances when of these supporting the two—conflating a issue of transactional integrity therewith of saving information after a database server loses power. [http://sunsite.univie.ac.at/textbooks/mysql/manual.html#IDX340] Since these claims contradicted basics of relational database design, they induced MySQL to exist as ridiculed by a bit of database experts. Disregarding of whether it were correct or even non, these claims come omitted inside further recent versions of the manual. MySQL in todays world allows a few trend lines for previously-dismissed features of relational integrity checking & dealings.

Whilst a beta version of MySQL Five.Cipher was freed inside March 2005, David Axmark, a co-founder of MySQL, said that "People have been criticising MySQL since we started for not having stored procedures, triggers and views," and "We're fixing 10 years of criticism in one release." [http://news.zdnet.co.uk/software/applications/0,39020384,39192964,00.htm]

Critics buy MySQL's popularity surprising inside the weak of the being of more open source database projects by using like performance & in nigher compliance to the SQL standards. MySQL advocates reply that a program serves its purpose for its users, world health organization come uncoerced to assume a program's limitations (which decrease sustaining each major revision) within exchange for speed, simplicity & rapid development. An additional, mayhap simpler, explanation for MySQL's popularity is that these are typically involved as a default component within great-prevent commercial web hosting plans, & so that for application developers (mostly utilizing PHP and Perl) MySQL is the lone DBMS guide unless it obviously work their have web hosts.

Occasionally users own likewise criticized MySQL AB's position on the licensing of the software package. Two or three open source projects, like Asterisk PBX, have reduced trend lines for MySQL because of licensing difficulties. Farther, there was a bit of disceptation generated on a distribution of GPL'500 MySQL library files by owning more open source applications (a large tilt arising using PHP, which has a license incompatible by using the GPL). This was late resolved whenever MySQL mass produced an exception for inclusion inside open source projects.

Inside September 2005, MySQL AB & a extremely controversial company SCO joined forces for "joint certification, marketing, sales, training and business development work for a version of the database for SCO's new OpenServer 6 version of Unix". Various MySQL employees gave what appeared to become a company's position, that it was committed to serving prevent users of a database, disregarding of their operating body guide, that a company would leave it to the courts to resolve the SCO licensing contestation & that more green open source databases use at times as well been ported to & trend lines OpenServer users.

Inside October 2005, Oracle acquired InnoDB Oy Inc, the company responsible the InnoDB storage engine that allows MySQL to provide such functionality as dealing & foreign keys. This might presumptively lead to changes around a arrangements in its handiness when, based on data from a [http://www.oracle.com/innodb/index.html press release], a contracts that produce the company's package available to MySQL AB come up for renewal (& presumptively renegotiation) occasionally instance inside 2006.

Trivia
The dolphin symbol in the MySQL logo was given the Swazi name Sakila in October 2002 after a appellative contest. [http://www.mysql.com/news-and-events/news/article_116.html] MySQL was number one freed internally in Will 23rd, 1995

Prominent users
Sabre, and its travel reservation formulas Travelocity LiveJournal, around [http://www.alexa.com/data/details/traffic_details?&compare_sites=&y=p&q=&url=livejournal.com 300 million page views] by the day Slashdot, the poster tike of high-traffic web sites, by owning in [http://www.alexa.com/data/details/traffic_details?&compare_sites=&y=p&q=&url=slashdot.org 50 million page views] by the day. 2005 MySQL Application of the Season winners: CNET Networks Friendster, additional than 85 million dynamic document views by the day, respire to trend lines more than Unity.Five billion MySQL interrogation by the day Wikipedia, more than 200 million question & Unity.Two million updates by the day sustaining peak loads of 11,000 interrogation by the second