David Rowley <dgrowle...@gmail.com> writes:
> The slightly annoying thing here is that the attached patch passes the
> TupleTableSlotOps as NULL in nodeSetOp.c. Per nodeAppend.c line 186,
> Append does not go to much effort to setting a fixed
> TupleTableSlotOps. Really it could loop over all the child plans and
> check if those have fixed slot types of the same type and then fix its
> own resulting slot. For nodeSetOps.c use case, since the planner
> (currently) injects the flag into the target list, it'll always
> project and use a virtual slot type. It's maybe worth coming back and
> adjusting nodeAppend.c so it works a bit harder to fix its slot type.
> I think that's likely for another patch, however. Tom is also
> currently working on nodeSetOps.c to change how all this works so it
> no longer uses the flags method to determine the outer and inner
> sides.
Yeah, I see no point in putting effort into improving the current
nodeSetOp implementation. There might be a reason to change
nodeAppend as you suggest for other use-cases though.
> I plan to push the attached patch soon.
I'll presumably need to rebase my nodeSetOp patch when this goes
in. I'll take a look then at whether the new code can be improved
with this additional feature.
regards, tom lane
