released announced their new SimpleDB web service. It is designed to take the place of a traditional RDBMS for about 80% of use cases. It seems to function more like Directory Service than your average MySQL install.
- There is no schema: You can add and remove any number of attributes to an item. Indexes are automagically updated.
- Attributes can have multiple values: Instead of creating tons of linking tables, that store simply primary IDs from one table to another, you can just add in multiple values to an attribute.
- Redundancy built in: No need to worry about clustering or replication. It's all built in and handled behind the scenes.
- Scalable: I assume that after the beta has been out for awhile they will relax the 100 domain, 10GB/domain size limits. Hopefully the 1024 byte attribute/value limit will be eased too.
- Lexicographical indexes: You'll need to pad integers with zero's, you can't use negative numbers, and dates need to be in ISO 8601 format.
It's hard to say right now how awesome this thing is going to be, since I can't get access to any code yet (it's in a limited beta). It's definitely a different way to think about databases, but if they can keep it fast, and deliver as advertised, it could change everything.