[angelbob]

Cassandra, for instance, makes it possible to query your join-type tables in relatively manual chunks using slice queries. You have to do a lot more of it in the application so you wind up with weird partial failures...

But at scale, weird partial failures, results as they are found and eventual consistency are usually preferable to a really long DB query that never returns.

Above a certain scale, big joins are simply not usable. NoSQL's manage-it-yourself approach is good for getting partial results where full results are too expensive.

You can think of it as applying a heuristic approach where an exact approach is too expensive, if it makes you feel less like NoSQL sullies the purity of databases :-)