MARS
This page is no longer maintained. Please go to MARS webdemo instead.
MARS was created as a a system for publishing XML from Mixed and Redundant Storage. But the core of the system is a universal tool for query reformulation and optimization under constraints, given an (equivalent) relational model.
Project initially started by Alin Deutsch, Lucian Popa, Arnaud Sahuguet and Val Tannen.
Maintained by Alin Deutsch and Nicola Onose.

About MARS

MARS is a system for publishing as XML data from mixed (relational+XML) proprietary storage, while supporting redundancy in storage for tuning purposes. The correspondence between public and proprietary schemas is given by a combination of LAV and GAV-style views expressed in XQuery. XML and relational integrity constraints are also taken into consideration. Starting with client XQueries formulated against the public schema, MARS achieves the combined effect of rewriting-with-views, composition-with-views and query minimization under integrity constraints to obtain optimal reformulations against the proprietary schema.
MARS achieves the uniform treatment of XML and relational storage by first reducing the reformulation problem to that of minimization of relational queries in the presence of relational constraints. The relational minimization is next performed by a core module which implements the Chase&Backchase algorithm.

Documentation

In order to write your own MARS scripts, take a look at the tests in the archive and at the file describing the commands.
More documents will be available soon.

Acknowledgement

This material is based upon work supported by the National Science Foundation under Grant No. IIS-0347968 (CAREER). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Last Release

Release Status

We are currently publishing the Chase&Backchase core module. We plan to release the reduction module in the near future.
In the interim, the current MARS release can be used as is for reformulation in relational database publishing. For XML publishing, one must encode by hand the XQuery views and the XML constraints into relational constraints.
MARS 0.4-pre-alpha   binary   source

Older releases