Data Integration by Describing Sources with Constraint Databases

We develop a data integration approach for the efficient evaluation of queries over autonomous source databases. The approach is based on some novel applications and extensions of constraint databases techniques. We assume the existence of a global database schema. The contents of each data source are described using a set of constraint tuples over the global schema; each such tuple indicates possible contributions from the source. The "source description catalog" (SDC) of a global relation consists of its associated constraint tuples. Such a way of description is advantageous since it is flexible to add new sources and to modify existing ones. In our framework, to evaluate a conjunctive query over the global schema, a plan generator first identifies relevant data sources by "evaluating" the query against the SDCs using techniques of constraint query evaluation; it then formulates an evaluation plan, consisting of some specialized queries over different paths. The ...

• Type: Conference
• Year: 1999
• Where: ICDE
• Authors: Xun Cheng, Guozhu Dong, Tzekwan Lau, Jianwen Su
• Keywords: Constraint Databases Techniques, Constraint Query Evaluation, Database, ICDE 1999, Query Rewriting Process