They’ve chosen their database – it is none other than MySQL. The release notes state:
Some features, such as the player window or support for databases other than MySQL, have been removed because either they posed insurmountable programming problems, or they didn’t fit our design decisions about how to distinguish Amarok in a saturated market of music players.
If you want to know why the decision was made, read MySQL in Amarok 2 – The Reality. It has a lot to do with the fact that MySQL can be embedded, and performs well. Its a generally useful read to see why SQLite and PostgreSQL was not chosen.
MySQL… powering the music of today!
(wonder as I may, if we will ever get any Enterprise customers, who make heavy use of Amarok over many computers, etc… – I’m thinking modern night clubs, lounges, et al)