[Company Logo Image]

Wednesday, February 28, 2001

01:43:43 AM


 

Constraint DataBases (CDBs) are an extension of relational databases that enrich both the relational data model and the relational query primitives with constraints.

For data-intensive applications over non-traditional data, CDBs hold the promise to combine the versatility of constraints with the commercial success of the relational approach.

This project focuses on the internal query representation of CDBs queries, i.e. Constraint Query Algebra (CQA).  CQA forms the ``middle layer'' of CDBs, underneath the user interface layer and above the disk access layer, providing a homogenous set of operators for expressing queries over any data.

Our Mission

We are developing a platform, called UMB-CDB, that will constitute an   experimental laboratory for Constraint Database design, implementation and querying. Furthermore, it will serve as an interactive learning platform in the graduate computer science curriculum.

The following Constraint Database challenges will be addressed in the process of building UMB-CDB:

(1) efficient data representation and algebraic operator implementation,
(2) query optimization techniques for CQA expressions,
(3) safe use of additional operators,
(4) integration with user-friendly metaphores for CDB front end,
(5) flexible interactive data visualization mechanisms.

To meet our objectives, we are putting a lot of effort in designing well its  infrastructure and in that perspective, we are using very powerful development tools. 

Project

The UMB-CDB system is built from the ground up in Java, using the latest industrial-strength system development tools.  (Here is a nice PS diagram of a preliminary version of our system design, generated with these tools ).  It is designed for the naive user, providing the common metaphors of spreadsheets and SQL for the front end data input and for querying. Constraint Query Algebra (CQA) serves as the middle layer, like an intermediate language in a compiler, although a direct CQA interface is also available.

Unlike traditional data, spatiotemporal data cannot be visualized as a simple table, and there is often no obvious "best" non-table-based visualization for all instances of a schema. UMB-CDB will have a flexible interactive mechanism for data visualization, allowing the user to specify which attributes are to be displayed and how.  This mechanism relies on an augmented schema, one that contains information useful for the visualization of data, not just for querying it.

Contact Information

Hit Counter

 

Send mail to jatik@cs.umb.edu with questions or comments about this web site.
Copyright © 2000 UMass Boston Constraint DataBases
Last modified: February 28, 2001