Synonyms
Wrapper-mediator approach to query evaluation
Definition
Information mediation is a query evaluation strategy where query processing against heterogeneous data sources is orchestrated by a middleware component called a mediator. The mediator handles query rewriting, dispatching query fragments to individual sources, and assembling individual query results into a composite query response. Source heterogeneity is managed by source wrappers which export a common data model view of the data at each source.
Main Text
Spatial information mediation extends the mediation ideas to processing complex spatial queries against sources and services that publish their spatial capabilities. This includes the ability to handle spatial data types and use spatial operations and predicates for querying spatial data sources. At the architecture level, it includes: (1) wrappers for spatial information sources that express spatial data sets using a common model, following spatial data exchange and...