The series about Apache Spark 2.4.0 features continues. After last week's discovery of bucket pruning, it's time to switch to Structured Streaming module and see its major evolution.
The idea of watermark was firstly presented in the occasion of discovering the Apache Beam project. However it's also implemented in Apache Spark to respond to the same problem - the problem of late data.
Data, especially in streaming applications, can very often arrive on late to the processing pipeline. Despite of that, Apache Beam is able to handle this case pretty easily thanks to watermark mechanism.