It's always nice to have a post explaining that you can comment in SQL. Most people are not aware of this, and it definitely helps when reading a DDL. I have t

It's always nice to have a post explaining that you can comment in SQL. Most people are not aware of this, and it definitely helps when reading a DDL. I have to agree that sometimes there are superfluous comments that harm more than help, since they add nothing to clarify the purpose of the column but consume your time. For example, in your post, the comment "required first name of the user" for an attribute called users.first_name adds no extra information. I'd also avoid using "required" as part of the comment, as that's implied in the NOT NULL constraint. However, other comments are very valuable, like the one for "created_at" or "data". Regarding having a last, nullable "data" hstore or jsonb column, I think it's a very good practice. A nullable column is almost always free (takes no extra disk space) and allows for storing information without a prior, clearly defined, or variable schema, without having to be ALTERing tables frequently, which usually is a challenge on its own.