Re: Evaluate expression at planning time for two more cases

On Tue, Jul 06, 2021 at 01:09:56PM +1200, David Rowley wrote:
> On Tue, 9 Mar 2021 at 05:13, Ibrar Ahmed <ibrar(dot)ahmad(at)gmail(dot)com> wrote:
> > It was a minor change therefore I rebased the patch, please take a look.
>
[...]
>
> This is not really an acceptable way to determine the notnull
> attribute value. Andy Fan proposes a much better way in [1].
> RelOptInfo is meant to cache the required Relation data that we need
> during query planning. IIRC, Andy's patch correctly uses this and does
> so in an efficient way.
>
> In any case, as you can see there's a bit of other work going on to
> smarten up the planner around NULL value detection. The UniqueKeys
> patch requires this and various other things have come up that really
> should be solved.
>
> Surafel, I'd suggest we return this patch with feedback and maybe you
> could instead help reviewing the other patches in regards to the NOT
> NULL tracking and maybe come back to this once the dust has settled
> and everyone is clear on how we determine if a column is NULL or not.
>
> Let me know your thoughts.
>

Hi Surafel,

We haven't seen an answer from you on this.
I'm marking the patch as "Returned with feedback" as was suggested.

--
Jaime Casanova
Director de Servicios Profesionales
SystemGuards - Consultores de PostgreSQL