XML database

An XML database is a data persistence software system that allows data to be specified, and sometimes stored, in XML format. These data can be queried, transformed, exported and returned to a calling system. XML databases are a flavor of document-oriented databases which are in turn a category of NoSQL database (meaning Not (only) SQL).

Rationale for XML in databases

There are a number of reasons to directly specify data in XML or other document formats such as JSON. For XML in particular, they include:

Steve O'Connell gives one reason for the use of XML in databases: the increasingly common use of XML for data transport, which has meant that "data is extracted from databases and put into XML documents and vice-versa". It may prove more efficient (in terms of conversion costs) and easier to store the data in XML format. In content-based applications, the ability of the native XML database also minimizes the need for extraction or entry of metadata to support searching and navigation.