Editing Hierarchical database model (section)

== History ==
The hierarchical structure was developed by IBM in the 1960s and used in early mainframe [[DBMS]].  Records' relationships form a treelike model.  This structure is simple but inflexible because the relationship is confined to a one-to-many relationship.  The [[IBM Information Management System]] (IMS) and [[RDM Mobile]] are examples of a hierarchical database system with multiple hierarchies over the same data.

The hierarchical data model lost traction as [[Edgar F. Codd|Codd]]'s [[relational model]] became the de facto standard used by virtually all mainstream database management systems. A relational-database implementation of a hierarchical model was first discussed in published form in 1992<ref>[http://www.kamfonas.com/id3.html Michael J. Kamfonas/Recursive Hierarchies: The Relational Taboo!] {{webarchive|url=https://web.archive.org/web/20081108151540/http://www.kamfonas.com/id3.html |date=2008-11-08 }}--The Relation Journal, October/November 1992</ref> (see also [[nested set model]]). Hierarchical data organization schemes resurfaced with the advent of [[XML]] in the late 1990s<ref>{{Cite web|url=http://www.ibm.com/developerworks/xml/library/x-matters8/index.html|title=Web Application Development|website=[[IBM]] }}</ref> (see also [[XML database]]).  The hierarchical structure is used primarily today for storing geographic information and file systems.{{citation needed|date=March 2013}}

Currently, hierarchical databases are still widely used especially in applications that require very high performance and availability such as banking, health care, and telecommunications. One of the most widely used commercial hierarchical databases is IMS.<ref>[https://web.archive.org/web/20120403013022/http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/ibmims/ IBM Information Management System]</ref>
Another example of the use of hierarchical databases is [[Windows Registry]] in the [[Microsoft Windows]] operating systems.<ref>{{cite web | url=http://msdn.microsoft.com/en-us/library/windows/desktop/ms724946(v=vs.85).aspx | title=Structure of the Registry - Win32 apps }}</ref>