附加字段实体的最优数据库结构。

I have a table in a DB (Postgres based), which acts like a superclass in object-oriented programming. It has a column 'type' which determines, which additional columns should be present in the table (sub-class properties). But I don't want the table to include all possible columns (all properties of all possible types).I have a table in a DB (Postgres based), which