What's the point of using Amazon SimpleDB?

Question

I thought that I could use SimpleDB to take care of the most challenging area of my application (as far as scaling goes) - twitter-like comments, but with location on top - till

Answer 1

Amazon is trying to get you to implement a simple object database. This is primarily for speed reasons. Think of the SimpleDB records as being a pointer/key to an element in S3. This way you can run queries (slow against SimpleDB to get results lists or you can directly hit S3 with a key (fast) to pull the object when you need to retrieve or modify records one-at-a-time.