The difference speaks to how they’re built, the type of information they store, and how they store it. Relational databases are structured, like phone books that store phone numbers and addresses.

In an interview in May with the IDG News Service, Tomas Ulin, Oracle vice president of MySQL engineering, described a project to bring the NoSQL-like speed of access to SQL-based MySQL.

Like Facebook and Twitter, Digg is also moving from MySQL , the initial Web 2.0 darling, to Cassandra. Cisco Systems Inc., hosting provider Rackspace and other firms also use Cassandra.

Twitter growth prompts switch from MySQL to 'NoSQL' database By Reuters February 23, 201010:52 PM PSTUpdated February 23, 2010 ...