I'm creating a filesystem and I think I'll be storing files in a DB (http://sietch.net/ViewNewsItem.aspx?NewsItemID=124 and http://blog.druva.com/2009/01/25/file-systems-vs-databases/ seem to indicate it's a good idea).
Since it's a filesystem, I'll need A LOT of I/O and REALLY fast. If I'm hosting on EC2, will Amazon SimpleDB be a decent solution for this?
SimpleDB has a maximum record size of a 1,000 BYTES so it is VERY poorly suited to storing files/blobs (unless they are tiny).
It is fairly common for people to use SimpleDB to index files and then to store the files in S3 which is much better suited for storing large objects.