Yes! Have one-to-many data that you know you will usually always grab all in one go, and won't ever participate in a relation? Arrays are the way to go. JSONB c

Yes! Have one-to-many data that you know you will usually always grab all in one go, and won't ever participate in a relation? Arrays are the way to go. JSONB can be similarly highly appropriate. They can greatly reduce the number of disk reads needed for certain workloads. Don't forget that both can be indexed in Postgres! And the indexes are more powerful than what you can do with the equivalent relational layout, as they support efficient subset queries.