We used datomic in production at Time Inc around 2016. The idea of an immutable database where you can track changes over time, or query the state of the universe at any given point, sounded amazing for marketing or compliance use cases. Unfortunately from a dev standpoint it did not feel like mature system, and the performance was not where we needed it to be.
Probably the most advanced database for triple stores these days is RDFox ( https://www.youtube.com/watch?v=-DnmuHtywFs ). While datomic uses datalog for querying, RDFox uses datalog for database reasoning, and sparql, a w3 standard for querying. As you add data to the database you can infer new facts. If you want immutability, simply add data in append mode only with a timestamp. But this idea you can add the business rules/logic to the database, and have it incrementally apply that logic as you add data is a recent advance by oxford AI research.
Probably the most advanced database for triple stores these days is RDFox ( https://www.youtube.com/watch?v=-DnmuHtywFs ). While datomic uses datalog for querying, RDFox uses datalog for database reasoning, and sparql, a w3 standard for querying. As you add data to the database you can infer new facts. If you want immutability, simply add data in append mode only with a timestamp. But this idea you can add the business rules/logic to the database, and have it incrementally apply that logic as you add data is a recent advance by oxford AI research.