> It feels like you're building a database out of an event stream. Many software applications, especially web application servers, are effectively a set of dat

> It feels like you're building a database out of an event stream. Many software applications, especially web application servers, are effectively a set of data structures updated incrementally from an incoming data stream, and then served to users. The analogy of many applications to a database (or an interpreter) is an accurate one and, in my personal experience, useful as well. > So you have to keep the log around basically forever. Different logs can have different retention periods, and you linearize across different logs by using a single writer per timeline. Many domains allow for enough splitting of timelines to enable effective parallel processing without compromising consistency (consider the case of distinct customer organizations using a time-tracking product - there's no reason they need to be able to write to the same database, and volume/contention within any individual organization is likely to be low, allowing for maintained performance).