[khalidmbajwa]

We are building a music streaming website. Think of it as a Spotify for Pakistan and Mongo has been wonderful for the kind of Data Structure we have. Its perfect for a catalogue like structure where objects can very easily nest inside each other. Each Artist has multiple albums, and multiple artists have multiple songs. All of this nestles very neatly inside eachother, and when i want a song, i almost always need its album and artist data, so i can very easily get that. Mongo is blazing fast on such kind of nested data structures. The only slight problems is where you have playlists and need to reference songs for a certain Artist. That could be countered by Data Duplication, since the song artist data etc once entered will very rarely change. So for us it makes perfect sense. You really need to understand what your data model is, and what you want from it, and then Mongo will be your friend, other than that it will cause you a world of pain.

[fragmede]

How does that hierarchical model work when songs or albums have more than one artist?

Why does a traditional relational db fail for such a well-defined data model? I mean, there's nothing about 'given an song (id), retrieve artist and album' that would make mongo inherently better.