>
>
> 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 theoret
johno wrote
> Oh, yes I do understand that if I remove the outer limit, the semantics of
> the query would change. However I am looking for the counterexample *with*
> the limit clauses. Maybe I just don't understand what relationally
> equivalent means, sorry about that.
>
> BTW this is to my und
Oh, yes I do understand that if I remove the outer limit, the semantics of
the query would change. However I am looking for the counterexample *with*
the limit clauses. Maybe I just don't understand what relationally
equivalent means, sorry about that.
BTW this is to my understanding a very simila
johno wrote
> Thanks for the quick reply David!
>
> However I am still unsure how these two queries are not relationally
> equivalent. I am struggling to find a counterexample where the first and
> third query (in email, not in gist) would yield different results. Any
> ideas?
Remove the outer LI
Thanks for the quick reply David!
However I am still unsure how these two queries are not relationally
equivalent. I am struggling to find a counterexample where the first and
third query (in email, not in gist) would yield different results. Any
ideas?
Jano
On Mon, Jul 21, 2014 at 11:31 PM, Da
johno wrote
> The question is... why is the query planner unable to make this
> optimization for the slow query? What am I missing?
Short answer - your first and last queries are not relationally equivalent
and the optimizer cannot change the behavior of the query which it is
optimizing. i.e. you
