
445Real-Time Big Data Processing for Domain Experts
developers explicitly compose desired sensor streams and transform
low-level data into more meaningful context using operators (comparable to
the spChains Stream Processing Blocks). Solar denes operators as custom-
developed solutions ranging from simple logic AND to complex supervised
machine learning, whereas spChains exploits highly efcient stream process-
ing engines, such as Esper, while also permitting nonstream solutions as
the ones envisioned in Solar. Moreover, while Solar denes the infrastruc-
ture, leaving developers free to design and implement the needed process-
ing ...