Abstract
In recent years, mobile devices and applications achieved an increasing development. In database field, this development required methods to consider new query types like location-dependent queries (i.e. the query results depend on the query issuer location). Although several researches addressed problems related to location-dependent query processing, a few works considered timing requirements that may be associated with queries (i.e., the query results must be delivered to mobile clients on time). The main objective of this paper is to propose a solution for location-dependent query processing under soft real-time constraints. Hence, we propose methods to take into account client location-dependency and to maximize the percentage of queries respecting their deadlines. We validate our proposal by implementing a prototype based on Oracle DBMS. Performance evaluation results show that the proposed solution optimizes the percentage of queries meeting their deadlines and the communication cost.
Highlights
Mobile units allow users to query a database anytime and anywhere, and to send queries the results of which are location-dependent
We essentially investigated the benefits of checking spatial validity before data transfer and considering real-time constraints while processing LD-queries
The experiments were performed on a Sun Blade 150 workstation (550 MHz processor speed, 300 MB memory size) communicating with a Sun Fire V240 workstation (1.5 GHz processor speed, 8 GB memory size) on which Oracle DBMS is setup
Summary
Mobile units allow users to query a database anytime and anywhere, and to send queries the results of which are location-dependent. The representation and querying of moving objects (e.g. select the closest free ambulance) have been considered by several works [5,16,24,27] In spite of their abundance, the proposed solutions do not meet all the locationbased application needs. The real-time constraints of some applications have not been considered enough Such new requirements generate the need to consider new types of queries such as locationdependent queries with real-time constraints. These constraints often appear as deadlines associated with queries.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
