Semantic Relations: The key to integrating and query processing in heterogeneous databases

1 This research was supported in part by NASA (under grants NAGW-4080, NAG5-5095, NAS5-97222, and NAG5-6830) and NSF (CDA-9711582, IRI-9409661, HRD-9707076, and ANI-9876409). Abstract Obtaining useful, complete, accurate information from on-line web data sources has become a challenging issue with multiple heterogeneous data sources on-line. With the increase of structured data sources moving on-line, collective integrated access to such information sources requires resolving semantic heterogeneity using innovative techniques for integration and query processing.