In this special case I would like to write a price list entry (product, brand, price etc.). When an event BrandNameChanged occurs, this writer should update the price list entry. But if I had to provide all information for this in all events that might occur in the different actors, it would be impossible to handle that. Hence, I decided to combine the necessary information the aforementioned event occurs. I assume that this should be a quite common problem that other - with more experience in event sourcing - might have solved already. Can you give me a hint where to look?