Add events in the past or in the future

[Soren-Knudsen]

It is posslbe via MartenDB to add events either in the past or in the future?

Scenario A: A person "Peter" will change name to "John" at t_future.
Scenario B: A shop owner finds out that that the expiration date on a product is wrong and wants to correct the mistake back in time from t_past.

t_past = 01/06/1960
t_now = 01/06/2020
t_future = 01/06/2125

[jokokko]

Not directly, though Copy & Transform might help you out here https://martendb.io/documentation/scenarios/copyandtransformstream/ (though currently it doesn't address event metadata, namely if one wanted to preserve the timestamp field value).

[Soren-Knudsen]

Thanks for your quick reply. That could work! Is it possible to chain the streams? When you for example load an aggregate ?

[jokokko]

You'd be looking at projections across streams: https://martendb.io/documentation/events/projections/custom/ You could certainly join the streams in a more "manual fashion" (load multiple streams, join evenst & push them to a new stream) to create a new event stream from 2 or more streams... Just requires thinking a bit about event ordering and whether running on a live system or not.