> > > Try following my lead and bottom-post, please. > Sorry for that.
> > Anyway, the query has no clue that because of the final LIMIT 100 that the > two different feeding queries are just going to happen to end up providing > the same result. Maybe, in this particular instance, it is theoretically > possible to make such a proof but generally that is not the case and so > such > an optimization has not made into the codebase even if it theoretically > could be done (I'm not convinced it could but do not know enough to explain > to someone else why I have that impression). > > I do not know enough to answer why this situation is any different from a > similar partitioning scenario. An example showing exactly what a similar > partitioning query looks like would help in this regard. > > If you are looking for considerably more insight into the planner workings > and why it does or doesn't do something you will need to wait for others. > I > can, to a reasonable degree, deconstruct a pair of queries and either > explain or guess as to why things are happening but that is mostly applied > deductive reasoning and not because I have any particular insight into the > codebase. > Thanks again for your time. Let's just wait for someone else and see where this will end up going. Jano
