Satisfying Complex Data Needs using Pull-Based Online Monitoring of Volatile Data Sources

Avigdor Gal

Associate Professor
Technion
Israel Institute of Technology

Abstract

Emerging applications on the Web, including mashups in general and Web feeds in particular, require better management of volatile data in pull-based environments. In a pull based setting, data may be periodically removed from the server. Data may also become obsolete, no longer serving client needs. In both cases, we consider such data to be volatile. To model such constraints on data usability, and support complex user needs we define profiles to specify which data sources are to be monitored and when. Using an abstraction of execution intervals we model complex profiles that access simultaneously several servers to gain from the used data. Given some budgetary constraints (e.g., bandwidth), we analyze algorithmic solutions to the problem of maximizing completeness. We discuss the complexity of the offline problem and propose an approximated solution. We next handle the online problem, introducing three heuristics for the online case. We use an extensive set of experiments that include real data and show that making use of the complexity level of profiles is dominant in many settings.

The talk is based on a paper to be presented in ICDE'2008. This is a joint work with Haggai Roitman (Technion and IBM) and Louiqa Raschid (University of Maryland, College Park).

Speaker Bio

Avigdor Gal is an Associate professor at the Technion. He received his D.Sc. degree from the Technion - Israel Institute of Technology in 1995 in the area of temporal active databases. During his studies, Avigdor has received the Miriam and Aaron Gutwirth Scholarship three years in a row (1993-1995). He has published more than 70 papers in journals (e.g. Journal of the ACM (JACM), ACM Transactions on Database Systems (TODS), IEEE Transactions on Knowledge and Data Engineering (TKDE), ACM Transactions on Internet Technology (TOIT), and the VLDB Journal), books (Temporal Databases: Research and Practice) and conferences (e.g., ICDE, ER, CoopIS) on the topics of data integration, temporal databases, information systems architectures, and active databases.

Avigdor is a member of the CoopIS Advisory Board, a member of IFIP WG 2.6, and a recepient of the IBM Faculty Award for 2002-2004. He is a member of the ACM and a senior member of IEEE.