Re: [HACKERS] Planner drops unreferenced tables --- bug, no?

>
> wieck(at)debis(dot)com (Jan Wieck) writes:
> >> It seems to me that the latter query must yield 9 rows (three
> >> occurrences of each value) to satisfy the SQL spec. The spec defines
> >> the result of a two-query FROM clause to be the Cartesian product of the
> >> two tables, period. It doesn't say anything about "only if one or more
> >> columns of each table are actually used somewhere".
>
> > Caution here!
>
> > After rewriting there can be many unused rangetable entries
> > floating around. Especially if you SELECT from a view, the
> > view's relation is still mentioned in the rangetable.
>
> I was thinking of forcing rangetable entries that are marked as
> 'inFromCl' to be included in the planner's target relation set,
> but those not so marked would only get added if referenced, same as now.
> Do you think that will not work?

I'm not sure and don't have the time to dive into. Just
wanted to point on an area of (maybe unexpected) side
effects.

Jan

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