NoSQL has, as a category, crossed the chasm from interesting science project to alternative data persistence mechanism. But while NoSQL tools like Cassandra and Riak are available in managed form via providers like Joyent and Heroku, DynamoDB is, in Popescu’s words: “the first managed NoSQL databases that auto-shards.”
It is also possible that SSD pricing contributed directly to the launch timing, with pricing for the drive type down to levels where the economics of a low cost shared service finally make sense.
SSDs
One underdiscussed aspect to the Dynamo launch is the underlying physical infrastructure, which consists solely of SSDs. This is likely one of the major contributing factors to the performance of the system, and in some cases will be another incentive to use Amazon’s platform as many traditional datacenters will not have equivalent SSD hardware available to them.
[A good analysis.]