流式系统基本术语

Bounded data(有界的数据)

 　　A type of dataset that is finite in size.

Unbounded data(无界的数据)

　　A type of dataset that is infinite in size.

Streaming system

　　A type of data processing engine that is designed with infinite datasets in mind.

Event time

　　This is the time at which events actually occurred.

Processing time

　　This is the time at which events are observed in the system.

Table

　　A holistic(整体) view of a dataset at a specific point in time. 

　　SQL systems have traditionally dealt in tables.

Stream

　　An element-by-element view of the evolution of a dataset over time.