NoSQL has always been a niche use case thing.
For some stuff, no ACID is no problem. They have their place. What I’m more suspicious of is things like Google offering distributed databases that they pretend as if they could break the CAP theorem.
You’ve gotten good answers from other folks but I’ll provide a ELI5:
Basically a set of rules in the database to make sure that it is immediately consistent.
NoSQL databases offer eventual consistency in exchange for speed so they are generally not considered to be ACID compliant.
Most traditional databases (MySQL, postgresql, etc.) are.
There are a couple of emerging companies that try to tackle speed for traditional databases. CockroachDB offers a postgress-based database that scales more like NoSQL while still offering ACID transactions.
TiDB is a similar company but for MySQL.
qaz
CosmicTurtle0 [he/him]