Re: Patch for removng unused targets

Hi Alexander,

I wrote:
> > From: Tom Lane [mailto:tgl(at)sss(dot)pgh(dot)pa(dot)us]

> > resjunk means that the target is not supposed to be output by the query.
> > Since it's there at all, it's presumably referenced by ORDER BY or GROUP
> > BY or DISTINCT ON, but the meaning of the flag doesn't depend on that.

> > What you would need to do is verify that the target is resjunk and not
> > used in any clause besides ORDER BY. I have not read your patch, but
> > I rather imagine that what you've got now is that the parser checks this
> > and sets the new flag for consumption far downstream. Why not just make
> > the same check in the planner?

> I've created a patch using this approach.

I've rebased the above patch against the latest head. Could you review the
patch? If you have no objection, I'd like to mark the patch "ready for
committer".

Thanks,

Best regards,
Etsuro Fujita