"Recent" Examples for Libraries?

Hello,
DB chef newbie here. I had a little trouble with Libraries and understanding how to use them with resources.
I was following the advice in this post about using resources.

Chef documentation gives this db github as one with complex examples.

Is this archived code of 3y ago still relevant/reusable?
The reason I ask is, this postgres cookbook was rewritten completely using resources.

Thank you for your time.