What is an XML database?
|
The XML:DB initiative has defined three different types of
XML database.
-
Native XML Database (NXD)
- a) Defines a (logical) model for an XML document -- as opposed to the
data in that document -- and stores and retrieves documents according to
that model. At a minimum, the model must include elements, attributes,
PCDATA, and document order. Examples of such models are the XPath data
model, the XML Infoset, and the models implied by the DOM and the events
in SAX 1.0.
- b) Has an XML document as its fundamental unit of (logical) storage,
just as a relational database has a row in a table as its fundamental
unit of (logical) storage.
-
c) Is not required to have any particular underlying physical storage
model. For example, it can be built on a relational, hierarchical, or
object-oriented database, or use a proprietary storage format such as
indexed, compressed files.
-
XML Enabled Database (XEDB) - A database that has an added XML
mapping layer provided either by the database vendor or a third party.
This mapping layer manages the storage and retrieval of XML data. Data
that is mapped into the database is mapped into application specific
formats and the original XML meta-data and structure may be lost. Data
retrieved as XML is NOT guaranteed to have originated in XML form. Data
manipulation may occur via either XML specific technologies(e.g. XPath,
XSL-T, DOM or SAX) or other database technologies(e.g. SQL). The
fundamental unit of storage in an XEDB is implementation dependent. The
XML solutions from Oracle and Microsoft as well as many third party
tools fall into this category.
-
Hybrid XML Database (HXD) - A database that can be treated as
either a Native XML Database or as an XML Enabled Database depending on
the requirements of the application. An example of this would be Ozone.
|
|
Why are XML databases interesting?
|
|
There is a whole world of applications where an XML database is the best
solution. For these applications an XML database will often far surpass a
relational database in convenience, ease of development and performance.
Applications where XML databases are often used consist of corporate
information portals, membership databases, product catalogs, parts
databases, patient information tracking, business to business document
exchange as well as many many others. We hope that through the efforts of
the XML:DB initiative that XML databases become widely accepted for all
applications where the storage of XML data is necessary.
|
|
What is the XML:DB initiative for?
|
XML:DB has four primary goals.
-
Development of technology specifications for managing the data
in XML Databases
-
Contribution of reference implementations of those specifications
under an Open Source License
-
Formation of a community where XML database vendors and users can
ask questions and exchange information to learn more about XML
database technology and applications.
-
Evangelism of XML database products and technologies to raise
the visibility of XML databases in the marketplace
|
|
Who is behind the organization?
|
|
XML:DB was formed by dbXML Group L.L.C, SMB GmbH and the OpenHealth Care
Group and is currently supported by a growing list of companies.
Please see the credits page for a list of all
current supporters.
|
|
Why a new organization?
|
|
The founders of the XML:DB initiative felt that in order for XML
databases to reach maturity within the marketplace a dedicated
organization was necessary to bring all interested parties together.
The XML:DB initiative is not designed as a replacement for the
efforts of the W3C or any other organization. Our goal is to work
together with those organizations while focusing on our unique area
of interest around XML database technology.
|
|
What license is used for reference implementations?
|
|
All reference implementations will be licensed under an Apache style
license.
|
|
What happens after the specifications are written?
|
|
When it makes sense to do so XML:DB will submit completed
specifications to an appropriate standards body for international
standardization.
|
|
How can you lay claim to the XML: namespace prefix?
|
|
The simple answer is we haven't. XML:DB is only the name of the
organization and has no relation to the actual namespace prefixes
used in our specifications.
|
|
