Perhaps to begin with just having A,B,C columns are fine and your comment justifies.
However, it still stands true in a test of time when you will end up with a lot more columns.
However, it still stands true in a test of time when you will end up with a lot more columns.
But I didn’t say it’s a good idea to do SELECT * (I never use it outside manual queries), just that it has no performance implication just by virtue of using it.