On-Demand Data Elevation in Hierarchical Multimedia Storage Servers

Given the present cost of memories and the very large storage and bandwidth requirements of large-scale multimedia databases, hierarchical storage servers (which consist of RAM, disk storage, and robot-based tertiary libraries) are becoming increasingly popular. However, related research is scarce and employs tertiary storage for storage augmentation purposes only. This work, exploiting the ever-increasing performance offered by (par. titularly) modern tape library products, aims to utilize tertiary storage in order to augment the system’s performance. We consider the issue of elevating continuous data from its permanent place in tertiary for display purposes. Our primary goals are to save on the secondary storage bandwidth that traditional techniques require for the display of continuous objects, while requiring no additional . RAM buffer space. To this end we develop algorithms for sharing the responsibility for * Research supported by the European Community under the ESPRIT Long Term Research Project HERMES no. 9141. t Research supported by the Canadian government under NSERC grant number 0155218, and by the 1996-97 Going Global STEP program. Permission to copy without fee all or part of this material is granted provided that the wpies am not made or distributed for direct wmmerciol advantage, the VLDB copyright notice and the title of the publication and its date appenr, and notice is given that copying is by permission of the Very Large Data Base Endowment. To copy otherwise, or to republish, requires a fee and/or special permission from the Endowment. Proceedings of the 23rd VLDB Conference Athens, Greece, 1997 York University North York, Ontario M3J lP3