Lets say you have two document types, customers and orders. A customer document contains basic information like name, address etc. and orders contain all the order information each time a customer orders something. When storing the documents, the type = order or the type = customer.
If I do a map function over a set of 10 customers and 30 orders it will output 40 rows. Some rows will be customers, some will be orders.
The question is, how do I write the reduce, so that the order information is "stuffed" inside of the rows that has the customer information? So it will return 10 rows (10 customers), but all the relevant orders for each customer.
Basically I don't want separate records on the output, I want to combine them (orders into one customer row) and I think reduce is the way?