Kouhei Kaigai <kaigai(at)ak(dot)jp(dot)nec(dot)com> writes:
> Simplified description of what I did is:
>   fval = makeFloat(psprintf("%.0f", plan_nrows));
>   custom_scan->custom_private = list_make1(fval);
So don't do that.  The lexer would never produce T_Float for an
integer-looking string, so I think it's out of scope for nodeRead()
to be able to reconstitute such a thing.  You could use %.1f, perhaps.
But actually, if you're worried about reconstituting exactly what you
had, aren't you risking precision loss anyway?  Maybe something like
psprintf("%.*e", DBL_DIG+3, plan_nrows) would be safer.
			regards, tom lane