Re: Patch for 8.5, transformationHook

On Sunday 19 April 2009 20:47:37 Pavel Stehule wrote:
> 2009/4/19 Peter Eisentraut <peter_e(at)gmx(dot)net>:
> > On Saturday 18 April 2009 18:09:00 Pavel Stehule wrote:
> >> There are lot of things, that should be done with current grammar only
> >> on transformation stage. Currently pg do it now. There are lot of
> >> pseudo functions, that are specially transformed: least, greatest,
> >> coalesce. After hooking we should do some similar work from outer
> >> libraries.
> >
> > There are surely other ways to accomplish this than an expression
> > transformation hook. Adding a property or two to the function definition
> > to do what you want could do it.
>
> should you describe it little bit more?

The question we should be asking is, what is it that prevents us from
implementing least, greatest, and coalesce in user space now? And then design
a solution for that, if we wanted to pursue this. Instead of writing
transformation hooks and then force every problem to fit that solution.