If we can't do upserts in EventStreams, what happens during Update CDC events?

[Kelderic]

I've been exploring EventStreams as a way to display real time bookings for my company, but sometimes the order records change, so I have to be able to handle updates as well as inserts, ie upserts. From searching the forums, upsert isn't supported as an EventStream transformation.

I know that we can use CDC from sevearal types of databases as an EventStream source. How do Update events work? Does the EventStream just ignore them? I feel like I'm missing something obvious because it seems like a basic functionality.

[lbendlin · Accepted solution]

Like Streaming Datasets, Eventstreams only work with immutable data (think IoT sensor data, for example).  If your booking information changes then you would need to consider using a SCD approach (likely SCD2 or a variation thereof).  So instead of update you would need to add the new state and then manage versions further downstream (pardon the pun).