Andres Freund <andres(at)anarazel(dot)de> writes:
> Potentially related note: for nodes like seqscan, combining the qual and projection processing into one expression seems to be a noticable win (at least when taking care do emit two different sets of deform expression steps).
There's just one problem: that violates SQL semantics, and not in
a small way.
select 1/x from tab where x <> 0
regards, tom lane