Profile Aware Retrieval Optimizer for Continuous Media

One of the key components of multimedia systems is a Continuous Media (CM) server that guarantees the uninterrupted delivery of continuous media data (i.e., audio and video). Queries imposed by applications, such as customized news-on-demand, might require the retrieval of one or more continuous objects from the CM server. Traditionally, multimedia systems have opted to guarantee that the CM server can display all the objects in the set to the user with no interruptions and with very strict display timing and ordering among the objects. This results in a single possible retrieval plan. However, for a class of applications, we have observed that depending on the user query, user proole, and session proole, there are a number of exibilities that can be exploited for retrieval optimization, namely: delay, ordering, presentation, and display-quality exibilities. In this paper, we describe a Proole Aware Retrieval Optimizer (Prime) that utilizes these exibilities to improve system performance by reducing retrieval contention at the CM server.