Sustainability of Digital Formats: Planning for Library of Congress Collections

The MySQL View Definition Format (FRM) stores the parameters of user generated queries in MySQL or MariaDB relational database management systems (RDBMS). Although both the MySQL View Definition and MySQL Table Definition formats share the same filename extension, FRM, MySQL View Definition Format "bears no resemblance to a base table FRM [as] it's purely textual".

FRM in the filename extension is short for "FoRM."

Unlike MySQL Table Definition Format, MySQL View Definition Format files are not created automatically. Users generate these FRMs via the prompted "CREATE VIEW" database action after formulating a query. This query and its associated metadata are then stored in an FRM file as either binary or plain text. This file allows users to recreate a MySQL View (reproduce their query) upon the database.

MySQL View Definition Format is depreciated from MySQL. It was used in production in Version 5.7 and earlier.

As the file format is no longer generated by MYSQL after version 5.7, documentation is limited and only available in legacy materials. MySQL has removed this information from its legacy documentation.

Official documentation from mysql.com, legacy.

This file is part of the widely used MySQL RDBMS and MariaDB RDMS.

None associated with the basic format. No license is required in creating, modifying, or exporting FRM files.

A matching version of MySQL must be used to load and transform FRM files.

This file is itself documentation for MySQL queries. This preserves parameters of the query, not the results or data itself. Unlike MySQL Table Definition files, MySQL View Definition Format files created in MySQL do not store the version used to create the FRM. View files created in MariaDB do store this information in the mariadb-version field.

MySQL version 5.7 or earlier and a matching version of the software that created the file.

None. There is no built-in mechanism for encryption, compression, or intellectual property protection.

MySQL View Definition files are generated using the MySQL system with the command 'CREATE VIEW' followed by the SQL statement.

For example: mysql\> CREATE VIEW v AS SELECT 1;

A MySQL View Definition file contains the query, a checksum, date, and other associated metadata. These values are stored in key:value pairs. The file is stored in either binary or a plain text.

Will save an FRM file including that query, a checksum, date, version, and other associated metadata. These values are stored as key:value pairs in either binary or text.

This file is limited to MySQL versions 5.7 and earlier. Editing can be done using the MySQL system via command line, desktop-based software such as MySQL Workbench, or web-based technology such as phpMyAdmin.

MySQL Table Definition files are stored in MySQL's data directory. This location will vary depending on the installation and machine. By default, the data directory can be found at the path /usr/local/mysql/for Linux and Mac machines.For Windows, that default path is C:\Program Files\MySQL.

FRM in the filename extension is short for "FoRM." This is a legacy terminology from a predecessor to MySQL called UNIREG (ca. 1979), which used the term "form" instead of "table" to represent database structure.

MySQL was created in 1995 by Swedish company MySQL AB which was founded by David Axmark, Allan Larsson and Michael "Monty" Widenius. The first internal release of MySQL was on May 23, 1995. MySQL is named after co-founder Monty Widenius's daughter, My.

In 2008, the company was sold to Sun Microsystems. In 2010, Sun Microsystems was purchased by Oracle. Co-founder Widenius opposed the Oracle acquisition and left to found his own RDBMS, MariaDB, based upon MySQL's open source codebase. Just as MySQL is named for Windenius' eldest daughter My, MariaDB is named for his second daughter Maria. This familiar relationship between MySQL and MariaDB is why both RDBMS are remarkably similar and both utilize the FRM format.