Applying Update Streams in a Soft Real-Time Database System

Many papers have examined how to efficiently export a materialized view but to our knowledge none have studied how to efficiently import one. To import a view, i.e., to install a stream of updates, a real-time database system must process new updates in a timely fashion to keep the database "fresh," but at the same time must process transactions and ensure they meet their time constraints. In this paper, we discuss the various properties of updates and views (including staleness) that affect this tradeoff. We also examine, through simulation, four algorithms for scheduling transactions and installing updates in a soft real-time database. Keywords: soft real-time, temporal databases, materialized views, updates. 1 Introduction The problem we study in this paper arose during the on-going implementation of the STRIP real-time database system. 1 This system [AGMK94b] provides traditional database services (e.g., SQL, indexing, recovery) with real-time facilities (e.g., transaction dead..