The world of scalable databases is not a simple one. They come in every race, creed, and color. Rick Cattell has brought some harmony to that world by publishing High Performance Scalable Data Stores, a nicely detailed one stop shop paper comparing scalable databases soley on the content of their character. Ironically, the first step in that evaluation is dividing the world into four groups:
- Key-value stores: Redis, Scalaris, Voldmort, and Riak.
- Document stores: Couch DB, MongoDB, and SimpleDB.
- Record stores: BigTable, HBase, HyperTable, and Cassandra.
- Scalable RDBMSs: MySQL Cluster, ScaleDB, Drizzle, and VoltDB.
The paper describes each system and then compares them on the dimensions of Concurrency Control, Data Storage Replication, Transaction Model, General Comments, Maturity, K-hits, License Language.
And the winner is: there are no winners. Yet. Rick concludes by pointing to a great convergence:
I believe that a few of these systems will gain critical mass and key players, and will pull away from the others by next year. At that point, open source contributors will likely migrate to those players.
From the paper: