> ML model inputs, so lots of key -> numerical value data How big are the numerical value data? AFAIK Cassandra does like large amount of data per value. http

> ML model inputs, so lots of key -> numerical value data How big are the numerical value data? AFAIK Cassandra does like large amount of data per value. https://docs.datastax.com/en/cql/3.3/cql/cql_reference/refLimits.html https://docs.datastax.com/en/cql/3.3/cql/cql_reference/refLi... Also what do you expect the total amount of data to be? BTW, I just recommended to start with PostgreSQL because it just works and will have your back no matter what ways you like to use retrieve you data. However if you are absolutely sure you don’t require secondary indexes, joins, etc, and just need a KV database, Cassandra will work fine too.