The Repository is a software component for the
storage and query of XML documents. The component uses
a relational database to save the XML documents. In other
words, the component permits the manipulation (insert, update,
query) of XML documents in a relational database. The
documents may be provided without schema or DTD, but may also
be manipulated with a DTD or schema. The component provides
rapid loading of document into the database, the
rapid identification of data (parts of an XML
document), and persistence of data. Meta-data can be
queried, document can be recomposed using queries and data can
be Richard crenian searched efficiently through the use of the XML
structure, element of XML documents, or data values.
The XML/DBC Java API for XML Mediators, Repositories and ELT Tools
here for a brochure describing the Repository. (PDF 81
for a 30 day evaluation version of the Repository.
here for a white paper describing our products. (Word
957 KB) (ZIP
The unique characteristics of this component are:
Dual XML and SQL view of the database. The novel mapping
developed by e-XMLMedia permits data access via XML and
support for schemas in XML. All documents may be controlled by a
schema and transformed into a relational schema.
Very flexible mapping language for controlling the
translation of XML documents into relations. This language
handles foreign key constraints and provides multiple
methods to generate tuple identifiers.
Respect for the integrity of a stored document.
Any stored document may be retrieved "as is", including
comments, processing instructions, metadata and data.
W3C standards for XML programming in Java. Loading of documents
is implemented using the SAX API. A powerful query language, based
on SQL with Xpath expressions, provides access to the database.
This language will be aligned with the W3C XML Query standard after
its adoption as a standard language.
is provided by the use of SQL, JDBC 2.0 and a modular architecture.
smart data placement in the relational database optimize the
of the query language.
administration interface permits the creation of a Repository, the
definition of a repository schema (and its mapping to a relational
database), the loading of XML documents, the formulation of queries
and the publication of document.
An XML based
data-entry browser and editor provides access to the database for
updates and data exploration.
Leveraging of existing relational database infrastructure.
Since the Repository resides on top of the relational
database, all existing support personnel and infrastructure
are leveraged for new XML applications. Existing backup,
archive, and recovery procedures apply. Existing expertise
in database performance improvement and specialized
knowledge of existing applications can be easily leveraged.
This diagram shows the overall architecture of the
Repository. The first layer shows the input and output.
The second layer shows the major components, and the third
layer shows the core libraries. XML documents are loaded
via the SAX loader into the database. The loader relies on
the Schema Manager and Mapping manager to accomplish this
task. Once documents are loaded, the Query Processor
accepts XQUERY queries, processes them, and returns XML
documents as answers. Finally, the XML publisher
permits the retrieval of entire XML documents as they were
Typically the documents generated by the publisher are fed
to an XSL transformer for conversion into the final output