Indexing, Query and Velocity-Constrained

Synonyms

Continuous queries; Spatio-temporal indexing

Definition

Moving object environments are characterized by large numbers of moving objects and numerous concurrent continuous queries over these objects. Efficient evaluation of these queries in response to the movement of the objects is critical for supporting acceptable response times. In such environments the traditional approach of building an index on the objects (data) suffers from the need for frequent updates and thereby results in poor performance. In fact, a brute force, no-index strategy yields better performance in many cases. Neither the traditional approach, nor the brute force strategy achieve reasonable query processing times. The efficient and scalable evaluation of multiple continuous queries on moving objects can be achieved by leveraging two complimentary techniques: Query Indexing and Velocity Constrained Indexing (VCI). Query Indexing relies on (i) incremental evaluation; (ii) reversing the role of queries and...