Using CRDTs requires that you define all the relevant operations as monoids. A lot of work has to go into the choices of monoids to yield usable results. Mono

Using CRDTs requires that you define all the relevant operations as monoids. A lot of work has to go into the choices of monoids to yield usable results. Monoids work fantastically well for things like upvotes on videos or whatever (so you'll notice that's always the first example given), but they don't really work for things like primary / unique keys, yet primary/unique keys are a critical requirement of most RDBMSes and schemas. Ergo, CRDTs don't work that well for relational databases. The situation is very different for collaborative text editing as there's no primary keys nor schema there, and humans are able to detect and correct nonsensical results. Mind you, I want CRDTs to work for RDBMSes -- the promise of CRDTs is fantastic. But do they? I suspect they do not.