Any scalable stream data processing engine must handle the dynamic nature of data streams and it must quickly react to every fluctuation in the data rate. Many systems successfully address data rate spikes through resource elasticity and dynamic load balancing. The main challenge is the presence of stateful operators because their internal, mutable state must be scaled out while assuring fault-...

Brain activation was examined using functional magnetic resonance imaging during mathematical problem solving in 7 young healthy participants. Problems were selected from the Necessary Arithmetic Operations Test (NAOT; R. B. Ekstrom, J. W. French, H. H. Harman, & D. Dermen, 1976). Participants solved 3 types of problems: 2-operation problems requiring mathematical reasoning and text processing,...

Query optimization is a difficult task in a distributed client/server environment as data location becomes a major factor. In order to optimize queries accurately, sufficient information must be available to determine which data access techniques are most effective. Optimization algorithms have an important impact on the performance of distributed query processing.. Various algorithms are used ...

A data warehouse (DW) contains multiple views accessed by queries. One of the most important decisions in designing a DW is selecting views to materialize for the purpose of efficiently supporting decision making. The search space for possible materialized views is exponentially large. Therefore heuristics have been used to search for a near optimal solution. In this paper, we explore the use o...