Evaluating hybrid queries through service coordination in HYPATIA

The emergence of mobile and ambient computing technologies brings democratization in the access to information and data; services play a crucial role, thereby opening new research challenges for data querying. A promising method to access data within these novel dynamic environments in a convenient and efficient way is declarative querying. Such queries, which we characterize as hybrid queries, involve streaming and on-demand data originated from services, possibly with temporal and mobile properties. To evaluate these queries we propose an approach implemented in the HYPATIA system, which addresses two main aspects (i) using service coordination for query evaluation and (ii) an efficient and flexible mechanism that facilitates incorporating new capabilities.