Adaptive query processing: Technology in evolution

As query engines are scaled and federated, they must cope with highly unpredictable and changeableenvironments. In the Telegraph project, we are attempting to architect and implement a continuously
adaptive query engine suitable for global-area systems, massive parallelism, and sensor networks. To
set the stage for our research, we present a survey of prior work on adaptive query processing, focusing
on three characterizations of adaptivity: the frequency of adaptivity, the effects of adaptivity, and the
extent of adaptivity. Given this survey, we sketch directions for research in the Telegraph project.