"Chengkai Li" <dbresearch@hotmail.com> writes:
> I plan to directly construct a query plan without going through the query
> optimizer, by manipulating the various data structures for representing
> query plan tree and parse tree. Is there any facility inside/outside
> postgresql that can be of help? Is there any known issue/difficulty related
> to this?
Only that your code *will* break in each future release, because we have
no hesitation about whacking those data structures around ...
regards, tom lane