Editing File system (section)

===Database file systems===
Another concept for file management is the idea of a database-based file system. Instead of, or in addition to, hierarchical structured management, files are identified by their characteristics, like type of file, topic, author, or similar [[metadata (computing)|rich metadata]].<ref>{{cite web|url=https://www.theregister.co.uk/2002/03/29/windows_on_a_database_sliced/ |title=Windows on a database – sliced and diced by BeOS vets |publisher=theregister.co.uk |date=2002-03-29 |access-date=2014-02-07}}</ref>

IBM DB2 for i <ref>{{cite web|url=http://www-03.ibm.com/systems/i/software/db2/index.html |title=IBM DB2 for i: Overview |publisher=03.ibm.com |access-date=2014-02-07 |archive-url=https://web.archive.org/web/20130802153156/http://www-03.ibm.com/systems/i/software/db2/index.html |archive-date=2013-08-02 |url-status=dead}}</ref> (formerly known as DB2/400 and DB2 for i5/OS) is a database file system as part of the object based [[IBM i]]<ref>{{cite web|url=http://www.ibm.com/developerworks/ibmi/newto/ |title=IBM developerWorks : New to IBM i |publisher=Ibm.com |date=2011-03-08 |access-date=2014-02-07}}</ref> operating system (formerly known as OS/400 and i5/OS), incorporating a [[Single-level store|single level store]] and running on IBM Power Systems (formerly known as AS/400 and iSeries), designed by Frank G. Soltis IBM's former chief scientist for IBM i. Around 1978 to 1988 Frank G. Soltis and his team at IBM Rochester had successfully designed and applied technologies like the database file system where others like Microsoft later failed to accomplish.<ref>{{cite web |url=https://www.theregister.co.uk/2002/01/28/xp_successor_longhorn_goes_sql/ |title=XP successor Longhorn goes SQL, P2P – Microsoft leaks |publisher=theregister.co.uk |date=2002-01-28 |access-date=2014-02-07}}</ref> These technologies are informally known as 'Fortress Rochester'{{Citation needed|date = June 2014|reason = Any news report or blog article mentioning this name and relating it to IBM i?}} and were in few basic aspects extended from early Mainframe technologies but in many ways more advanced from a technological perspective{{Citation needed|date = June 2014|reason = Is there any articles supporting this technological superiority?}}.

Some other projects that are not "pure" database file systems but that use some aspects of a database file system:
* Many [[Web content management system]]s use a [[Database management system|relational DBMS]] to store and retrieve files. For example, [[XHTML]] files are stored as [[XML]] or text fields, while image files are stored as blob fields; [[SQL]] SELECT (with optional [[XPath]]) statements retrieve the files, and allow the use of a sophisticated logic and more rich information associations than "usual file systems." Many CMSs also have the option of storing only [[metadata]] within the database, with the standard filesystem used to store the content of files.
* Very large file systems, embodied by applications like [[Apache Hadoop]] and [[Google File System]], use some ''database file system'' concepts.