Recently I started to take a look at Postgresql on the Source Level. I wanted to extend the Parser by a simple Clause which isn't as easy as I expected.
Hence I'm here asking for help. This might seem trivial for a Person which is able to answer this Question but please take a moment of your time and help a
fellow coder out. 

 

My Objective is to add a new Clause after the WHERE Clause in a SELECT Statement which modifys the order of my result. I allready invested some time to get familar
with the Bison part in source\src\backend\parser so adding new Keywords seems possible. The question now is in which Files do I need to add what to make it work.
Yes this question seems a bit broad but Information I found was confusing or outdated.

 

I would really appreciate if someone could hack me a quick example of a new clause lets call it ADDITIONAL with Keywords HIGH, LOW to order columns. I just want the construct. What
the Keywords accomplish and the Algorithm is something I'm gonna try to figure out on my own. I just need to know in which File and which Line I need to enter my Code.

 

I appreciate any help I can get and if needed I'll add some additional Information.