Information AboutMysql |
| CATEGORIES ABOUT MYSQL | |
| database management systems | |
| open source database management systems | |
| fsf---unesco | |
|
name = MySQL
MySQL is a Multithread ed, Multi-user , SQL Database Management System ( DBMS ) with an estimated six million installations. MySQL AB makes MySQL available as Free Software under the GNU General Public License (GPL), but they also Dual-license it under traditional Proprietary licensing arrangements for cases where the intended use is incompatible with the GPL. Unlike projects such as Apache , where the software is developed by a public community, and the copyright to the codebase is owned by its individual authors, MySQL is owned and sponsored by a single for-profit firm, the Swedish company MySQL AB , which holds the copyright to most of the codebase. The company develops and Maintains the system, selling support and Service Contract s, as well as Proprietary -licensed copies of MySQL, and employing people all over the world who collaborate via the Internet . MySQL AB was founded by David Axmark , Allan Larsson , and Michael "Monty" Widenius . PROGRAMMING LANGUAGES There are , C++ , C# , Borland Delphi (via dbExpress), Eiffel , Smalltalk , Java (with a native Java driver implementation), Lisp , Perl , PHP , Python , Ruby , REALbasic , FreeBasic , and Tcl ; each of these uses a specific API. An ODBC interface called MyODBC allows additional programming languages that support the ODBC interface to communicate with a MySQL database, such as ASP . MySQL is mostly implemented in ANSI C, and, that being a common "lingua franca" for system libraries, tends to use that as its "native" language. USES MySQL is popular for Web Applications such as MediaWiki or PHP-Nuke and acts as the database component of the LAMP and WAMP platforms (Linux/Windows-Apache-MySQL-PHP/Perl/Python). Its popularity as a web application is closely tied to the popularity of PHP , which is often combined with MySQL and nicknamed the ''Dynamic Duo''. It is easy to find many references that combine the two in websites and books (''PHP and MySQL for Dummies'', ''PHP and MySQL Bible'', ''Beginning PHP and MySQL'', etc.) The claim made in many books is that MySQL is easier to learn and use than many other database applications. An example from the ''Dummies'' book is that you can quit MySQL with an obvious command of either ''exit'' or ''quit'', although this is true for many other database applications. ADMINISTRATION To administer MySQL databases one can use the included and MySQL Query Browser . A widespread and popular alternative, written in PHP , is the free software web application PhpMyAdmin . PROGRAM SPECIFICATIONS Platforms MySQL works on many different Platforms —including AIX , BSDi , FreeBSD , HP-UX , GNU/Linux , Mac OS X , NetBSD , Novell 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 . A port of MySQL to OpenVMS is also available {Link without Title} . The latest production version As of May 2006, MySQL offers production version 5.0.21. It includes the following features:
Future releases The MySQL 5.1 roadmap outlines support for:
Foreign Key support for all storage engines will likely be released with MySQL 5.2 (although it has been present since version 3.23 for InnoDB ). The current MySQL 5.1 development release is 5.1.9 beta . Distinguishing features The following features are implemented by MySQL but not by some other RDBMS es:
Server compilation type There are 3 types of MySQL Server Compilations:
Source code specifics MySQL is written in a mixture of C and C++ . The SQL parser uses Yacc and home-brewed Lexer . A document describing some of the internal structures of the code and the coding guidelines is available from the MySQL web site. SUPPORT Via MySQL Network MySQL AB offers support itself, including 24/7 30 minute response time, with the support team having direct access to the developers as necessary to handle problems. In addition it hosts forums and mailing lists and employees and other users are often available in several IRC channels providing assistance. Members of the MySQL Network enjoy access to binaries and software that is certified for their particular operating system, and the codebase changes much less frequently then the Community Edition of the MySQL Database Server engine. The Network maintains several levels of membership based on importance and urgency for response times. LICENSING Both the MySQL server software itself and the client libraries are distributed under a dual-licensing format. Users may choose the Some users have independently continued to develop an earlier version of the client libraries, which was distributed under the less-restrictive Lesser General Public License . {Link without Title} PRONUNCIATION "MySQL" is officially pronounced as "My Ess Queue Ell" , not "My sequel" {Link without Title} . However, the company doesn't mind if others use either the "My sequel" form or other local variations if they are preferred by the speaker. The "My" portion of the name comes from the name of Monty's child, spelled "My" but pronounced in the local language as "Me". The "SQL" portion uses the fully spelled-out pronunciation of the Initials , S-Q-L, not the "sequel" pronunciation, which conflicts with the earlier IBM database of that name. {Link without Title} The Swedish (MySQL AB is a Swedish company) word "Myskväll" (cozy evening, or even My's evening, "Mys kväll") is pronounced in a similar way but this might be a coincidence. Nevertheless this pronunciation is quite usual in Sweden. CRITICISMS OF MYSQL Early versions of MySQL included few standard Relational Database Management System (RDBMS) features, and the current production version still lacks many properties found in other SQL RDBMSs. This has led some database experts, such as Chris Date and Fabian Pascal , to criticize MySQL as falling short of being an RDBMS. Many of the early criticisms have been remedied in later versions of the software, including the lack of transactions and relational integrity constraints. These are features necessary to support the " ACID Properties " for relational databases, which allow the DBMS to ensure that client applications cannot interfere with one another or insert inconsistent values. Other criticisms include MySQL's divergence from the SQL standard on the subject of treatment of NULL values and default values. Its handling of dates allows storing a date with a day beyond the last day of a month with less than 31 days, and arithmetic operations are vulnerable to either integer overflow or floating point truncation ([http://sql-info.de/mysql/gotchas.html ). These values are treated according to the SQL standards in MySQL version 5 through the use of special SQL Modes . Earlier versions of the MySQL manual included claims that certain missing features (considered essential for SQL-compliant RDBMSs) were useless or even harmful, and that users were better off without them. One section, entitled "Reasons NOT to use Foreign Keys constraints" advised users that relational-integrity checking was difficult to use and complicated a database application, and that its only useful purpose was to allow client software to diagram the relationships between database tables. [http://sunsite.univie.ac.at/textbooks/mysql/manual.html#Broken_Foreign_KEY Another section claimed that a DBMS lacking transactions can provide data-integrity assurances as reliably as one supporting transactions—conflating the issue of transactional integrity with that of saving data when the database server loses power. [http://sunsite.univie.ac.at/textbooks/mysql/manual.html#IDX340] Since these claims contradicted basic principles of Relational Database design, they caused MySQL to be ridiculed by some database experts. Regardless of whether they were right or not, these claims are omitted in more recent versions of the manual. MySQL today allows some support for previously-dismissed features of relational integrity checking and transactions. When the beta version of MySQL 5.0 was released in 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." {Link without Title} MySQL 5.0's 13 October build 5.0.15 was released for production use on 24 October 2005 , after more than two million downloads in the 5.0 beta cycle. Critics find MySQL's popularity surprising in the light of the existence of other open source database projects with comparable performance and in closer compliance to the SQL standards. MySQL advocates reply that the program serves its purpose for its users, who are willing to accept the program's limitations (which decrease with every major revision) in exchange for speed, simplicity and rapid development. Another, perhaps simpler, explanation for MySQL's popularity is that it is often included as a default component in low-end commercial web hosting plans, so that for application developers (mostly using PHP and Perl) MySQL is the only DBMS choice unless they want to operate their own web hosts. Some users have also criticized MySQL AB's position on the licensing of the software. A few open source projects, such as Asterisk PBX , have reduced support for MySQL because of licensing difficulties. Further, there was some controversy generated regarding the distribution of GPL'd MySQL library files with other open source applications (the biggest controversy arising with PHP, which has a license incompatible with the GPL). This was later resolved when MySQL made an exception for inclusion in open source projects. In September 2005, MySQL AB and the highly controversial company SCO joined forces for "joint certification, marketing, sales, training and business development work for a commercial version of the database for SCO's new OpenServer 6 version of Unix". Various MySQL employees gave what appeared to be the company's position, that it was committed to serving end users of the database, regardless of their operating system choice, that the company would leave it to the courts to resolve the SCO licensing controversy and that other common open source databases have also been ported to and support OpenServer users. In October 2005, come up for renewal (and presumably renegotiation) some time in 2006. In February 2006, , another storage engine used by MySQL. TRIVIA
PROMINENT USERS
SEE ALSO
EXTERNAL LINKS
|
|
|