MySQL
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| subcat=Databases | | subcat=Databases | ||
| extensions={{ext|frm}}, {{ext|myd}}, {{ext|myi}}, {{ext|ibd}} | | extensions={{ext|frm}}, {{ext|myd}}, {{ext|myi}}, {{ext|ibd}} | ||
+ | | pronom={{PRONOM|fmt/868}}, {{PRONOM|fmt/1197}} | ||
}} | }} | ||
:''MySQL: the Comic Sans of databases. Except Comic Sans has uses.'' | :''MySQL: the Comic Sans of databases. Except Comic Sans has uses.'' | ||
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'''MySQL''' is a popular open-source database system using the [[SQL]] query language. Its files are traditionally stored with the field definitions in '''.frm''' files, the data in '''.myd''' files, and indexes in '''.myi''' files. The newer ''InnoDB'' storage engine replaces the .myd and .myi files with a shared "ibdata1" file, and in most cases an '''.ibd''' file for each database. | '''MySQL''' is a popular open-source database system using the [[SQL]] query language. Its files are traditionally stored with the field definitions in '''.frm''' files, the data in '''.myd''' files, and indexes in '''.myi''' files. The newer ''InnoDB'' storage engine replaces the .myd and .myi files with a shared "ibdata1" file, and in most cases an '''.ibd''' file for each database. | ||
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+ | == UTF-8 in MySQL == | ||
+ | |||
+ | To use the proper [[UTF-8]] standard for character encoding, you need to designate the character set parameter as [https://dev.mysql.com/doc/refman/5.5/en/charset-unicode-utf8mb4.html utf8mb4], because the more appropriate 'utf8' was already used to designate a subset of this standard which encompasses only the BMP characters (in the range U+0000 to U+FFFF), not the supplementary characters at higher code points, which take four bytes to express in UTF-8. | ||
== File format information == | == File format information == | ||
− | * [http://dev.mysql.com/doc/internals/en/frm-file-format.html .frm files] | + | * [https://web.archive.org/web/20131210155407/http://dev.mysql.com/doc/internals/en/frm-file-format.html .frm files (archived)] |
− | * [http://dev.mysql.com/doc/internals/en/myisam-record-structure.html .myd and .myi files] | + | * [https://web.archive.org/web/20131210151954/http://dev.mysql.com/doc/internals/en/myisam-record-structure.html .myd and .myi files (archived)] |
== Other links == | == Other links == | ||
* [[Wikipedia:MySQL|Wikipedia article]] | * [[Wikipedia:MySQL|Wikipedia article]] | ||
* [http://www.mysql.com/ Official site] | * [http://www.mysql.com/ Official site] | ||
+ | * [http://reddragdiva.dreamwidth.org/593924.html Why MySQL is not my favourite database.] | ||
+ | * [http://grimoire.ca/mysql/choose-something-else Do Not Pass This Way Again] | ||
+ | * [https://bits.ashleyblewer.com/blog/2023/08/11/researching-file-formats-2-mysql-table-definition-format/ MySQL Table Definition Format Blog post] |
Latest revision as of 16:50, 18 August 2023
- MySQL: the Comic Sans of databases. Except Comic Sans has uses.
- -- David Gerard
MySQL is a popular open-source database system using the SQL query language. Its files are traditionally stored with the field definitions in .frm files, the data in .myd files, and indexes in .myi files. The newer InnoDB storage engine replaces the .myd and .myi files with a shared "ibdata1" file, and in most cases an .ibd file for each database.
[edit] UTF-8 in MySQL
To use the proper UTF-8 standard for character encoding, you need to designate the character set parameter as utf8mb4, because the more appropriate 'utf8' was already used to designate a subset of this standard which encompasses only the BMP characters (in the range U+0000 to U+FFFF), not the supplementary characters at higher code points, which take four bytes to express in UTF-8.