The watermark

Worked examples, recomputed

Every number the mechanisms quote for this relationship is recomputed from it, so none of them disagrees with it.

• δ from p99 (30 s) to p99.99 (1 h): 100× fewer late records for 120× more waiting

Where it appears

Each mechanism states it in its own names. The general symbol each name stands for is shown with it.

• Time & Temporal Semantics

  When am I allowed to act on data that may still be incomplete, and what do I owe the reader if I was wrong?

  $$\text{watermark}=(\text{largest event time observed so far})-\delta$$

  Read it in place →