> Also think of the power that would be available if there were some relational table capability (true real MySQL ACID) right inside MongoDB whenever it was nee

> Also think of the power that would be available if there were some relational table capability (true real MySQL ACID) right inside MongoDB whenever it was needed, if they were the 'same animal', rather than having to use two totally and completely separate DBs Just use Postgres (or several other options) then? It has all that built right in if it's what you need. But... > if you need NoSQL and also ACID in an app, which 99% of apps DO NEED, at some point, ...I doubt 99% of apps really need this. > once an app grows beyond the round-one funding startup-toy phase and MongoDB falls flat in it's RDB capabilities. Or don't try to force MongoDB to behave like a RDB and you won't hit those problems? I just moved a system from Postgres to MongoDB, and it's running faster on way cheaper hardware now. Not because either database is inherently better than the other, but the use case lined up with mongodb perfectly and the old model was leveraging Postgres really poorly. Eventual consistency is fine, and I can denormalize certain data for faster reads because I know it won't be modified later.