At some point it will occur to you to ask, "What are the current configuration settings?"
Your first thought is probably "look in
postgresql.conf". That works, but only as long as there is only one parameter file. If there are two, then maybe you're reading the wrong file! (How do you know?). So the cautious and accurate way is not to trust a text file, but to trust the server itself.
Also, we learned in the recipe When to set parameters that each parameter has a scope that determines when it can be set. Some parameters can be set through
postgresql.conf, but others can be changed afterwards also. So the current value of configuration settings may have been subsequently changed.
We can ...