I have a question for the noSQL guys.
Let's say I have a standard customer order system.
Customer has many Orders
Order has many Items
How do I get the number of Hammers ordered? I don't care about any Customer or Order information. In an RDBMS, this is easy - I just query the Items table for hammers.
In MongoDB, for example, using embedded documents, I'd have to dig my way through the Customer document, Orders collection, Items collection to get at each Item, or I'd use document references, which is just duplicating the relational structure, so I get no benefit (plus no enforcement of foreign keys, so I could add an item that doesn't exist).
Am I missing something?