In which module does query rewriting takes place

Hi,

We are trying to introduce access control. For this we have to rewrite the
input query by replacing each relation by its corresponding authorized view.
Which part of the code should we modify for this.

Till now we have thought of the following:

1. We take as input the parse tree generated by the parser.
2. We implement a "new" module which rewrites the parse tree into the format
we want.
3. We feed this new parse tree into the optimizer.

Does a module exist which rewrites the parse tree generated. We saw that
there exist some rewrite module in /src/backend/rewrite. Is that the correct
module to make changes to!

Thanks
Shaunak

--
It is not the aptitude but the attitude that decides a persons altitude
Shaunak Godbole
Senior Undergraduate
Computer Science Dept.
IIT Powai, Mumbai 400076
Ph no: 9819841537