[heavyset_go]

That's because you install versioned packages like postgresql-15: https://tracker.debian.org/pkg/postgresql-15

That way you can have multiple versions of the same package.

[xpasky]

You mean there is some other way to install postgresql in Debian?

[heavyset_go]

No, what I meant is that the install path for Postgres on Debian involves installing versioned packages. It's the only approved way of installing Postgres from the Debian repos that I'm aware of.