Andreas Haumer wrote:
>
> I think the planner could do the following:
>
> a) It could make a better decision in which direction to scan
> the partitions (depending on sort order involved in the query)
>
> b) It could stop scanning as soon as there can not be any further
> resulting row according to the CHECK constraints given on the tables.
[snip]
> Perhaps the logic to implement this is complex, but IMHO
> it _should_ be doable (and proofable), shouldn't it?
Ah, it might be do-able for some subset of cases, but is it
cost-effective to check for in *all* cases? Don't forget the constraints
and where clauses can be arbitrarily complex.
--
Richard Huxton
Archonet Ltd
