[benjiro]

The problem is that Postgres uses something like 24B overhead per row. That is not a issue with small Tables, but when your having a few billion around, each byte starts to add up fast. Then you a need link tables that explode that number even more, etc ... It really eats a ton of data.

At some point you end up with binary columns and custom encoded values, to save space by reducing row count. Kind of doing away with the benefits of a DB.

[direwolf20]

Yeah postgres and mariadb have some different design choices. I'd say use either one until it doesn't work for you. One of the differences is the large row header in postgres.