"Pavan Deolasee" <pavan.deolasee@gmail.com> writes:
> I am trying to figure out the best way to extract this information. Is there
> any
> existing code to get all attributes used in the expressions ? Or do I need
> to walk the tree and extract that information ?
There are a number of near matches in backend/optimizer/util/var.c,
but nothing that has exactly the API you probably want, which I'd think
would be to extract a bitmapset of the varattnos of level-zero Vars.
contain_var_reference() could be used repeatedly but that seems
tremendously inefficient. I'd suggest coding up some new function
using what's there for reference.
regards, tom lane