View maintenance in mobile computing
Ouri Wolfson, Prasad Sistla, Son K. Dao, Kailash Narayanan, Ramya Raj · ACM SIGMOD Record · 1995
I n t r o d u c t i o nMobile users of portable computers will soon have onfine access to a large number of databases via wireless networks.For example, while on the road, passengers will access airfine and other carriers schedules, and weather information; investors will access prices of financial instruments, sales people will access inventory and other corporate data, commuters will access traffic information.However, access to an onfine database may be unavailable when the user is out-of-range of the wireless network.Furthermore, sending access-requests from the mobile computer to the onfine database may be expensive due to limited uplink bandwidth, and also due to the fact that sending messages is a significant drain on the portable battery.These two problems can be alleviated by maintaining a materialized view at the mobile computer.This view will be updated using wireless data messages, as the onfine database changes.This will also localize access, thus improving access time to the view.Therefore, to better deal with the problem of disconnection and to improve response time, the view should be materialized at the mobile computer.As explained above, sometimes communication cost can also be reduced by materialized views; but not always.For example, if the materialized