SQL Schema vs Schema

Question

As far as I can tell, the word “schema” is used in two different ways:

• The schema is the structure of the database, including the tables and how they are related
• The schema is a sort of namespace allowing you to create virtual collections of database objects

There is an article at https://dataedo.com/kb/data-glossary/what-is-database-schema which highlights the different meanings, but doesn’t appear to explain why they use the same name.

Are the different uses of the word in fact related in some subtle but very interesting way, so that one meaning naturally leads to the other?

Answer 1

I think only the developer who first implemented a concrete object they called a schema, from many moons ago, could give you an official answer on why they chose the word schema here. But I could speculate their reasoning being that a schema (the object) is a collection of related entities (usually) that make up the structure of a subject matter. That subject matter could potentially be its own database, if one chose to architect it that way, and without schemas it would have to be. Otherwise there would be intermingling of unrelated entities within the same database.

One may think of a schema abstractly when going by your first definition, but I think they wanted to implement a concrete object to serve the purpose of organizing the database when there's multiple structures that aren't necessarily directly related.