[mdm12]

In event sourced systems, you project the event stream into read models, of which there can be many (relational, time series, etc.) If you're familiar with functional programming, it is essentially a fold operation over the stream of events into a single state.

Having worked with event sourced systems in the past, there are benefits in having a persisted explicit event history, but there is much added complexity (how do those read models actually get generated? how do you version the model? do you have snapshots of your read models?). In my experience, the additional complexity was not worth it for most contexts in which the pattern was applied...