Execution and Optimization Techniques for Approximate Queries in Heterogeneous Systems

摘要

High-level queries can be used for describing scenarios of complicated analytical processing in environments of distributed heterogeneous information resources. Simultaneous abrupt increase in volume and variety of data types available for mass processing in information networks and toughening of requirements on time spent for analyzing them resulted in the need of revising the known query execution and optimization methods. In this survey, approaches to the execution and optimization of high-level precise and approximate queries are considered; unresolved problems and possible ways to solve them are also discussed.