Page History

...

The FLIP will make changes to Flink's watermark and timestamp concepts. To help understand the intuition behind the design, we will introduce the relevant concepts in this section.

Probe Side: The left side of the stream in a temporal join The left side of the stream in a temporal join, sometimes referred to as the Fact Table. Usually Usually, the data on the Probe Side doesn't need to be retained after processing.

Build Side: The right side of the stream in a temporal join The right side of the stream in a temporal join, which can be a versioned table. It is also known as the Dimension Table. Typically, the Build Side has the latest data for each key.

Watermark: Inform operators that no elements with a timestamp older than or equal to the watermark timestamp should arrive at the operator.

...