Most modern database software is based on the disk storage system of the operating system. There were some exceptions in the high end market for engines such as Sybase which had its own disk controller utilizing raw disks not accessible by the operating system.
Recently Facebook released a new database into the Open Systems environment based on flash storage. The concept of the database is not new. It uses the now common key-value storage model. The biggest difference is that this database, RocksDB is designed to run on an application server and store the results in Flash.
What makes RocksDB different than other Data Storage? You can deploy MongoDB on machines using flash drives. The difference is the way in which data is used. The main purpose of RocksDB is to distribute data along with the applications utilizing the data. The goal is to reduce the network latency for acquiring data.
Instead of having centralized application servers that obtain data from centralized data sources the data request is instead sent to the application server containing a local cache of data on high speed flash storage.
Take a look at the detailed blog from Dhruba Borthakur as he explains the for RocksDB.
Cheers,
Ben