CQA/CDB Project Applied Theory Lab |
| 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 MissionWe are developing a platform, called CQA/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 CQA/CDB:
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. ProjectThe CQA/CDB system is built from the ground up in Java, using the latest industrial-strength system development tools. (Here is a Diagram of a preliminary version of our system design ). 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. CQA/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. This material is based upon work supported by the National Science Foundation under Grants No. 9733678 and 0296195. 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. |