We tried using SimpleDB initially for a startup. We store a lot of numerical data. When it came time to actually query this data and do anything meaningful with

We tried using SimpleDB initially for a startup. We store a lot of numerical data. When it came time to actually query this data and do anything meaningful with it we ran into a lot of issues because all values are stored as untyped strings (comparison and ordering is always lexicographic). There are ways around this using zero-padding, but they are ugly and difficult. The SimpleDB query language is also limiting if you are accustomed to SQL and relational data structures. In the end it just wasn't the right fit and we reverted to an RDBMS.