The product data will be in multiple physical replicated shared-nothing databases each of which has the entire dataset - a single logical database. The principle of sharding is that each database has a subset of the data and you place some logic in front of it to direct the query to the right place. Now if I'd been able to buy kitchenware but not garden tools one day, then I might say their product database was sharded. But Amazon is smarter than that.
Are you still arguing that I said Amazon sharded their database? Because I've re-read what I said, and what you said like 4 times and I can't see where I said they shard.
Actually, Amazon is kind of sharding their database: They encapsulate every kind of data into a program that manages it:
>What I mean by that is that within Amazon, all small pieces of business functionality are run as a separate service. For example, this availability of a particular item is a service that is a piece of software running somewhere that encapsulates data, that manages that data.
