Good evening Daniël,

I have introduced the suggested optimization, considering some more
cases like $p = (1 to 10), $p >= 1 and $p <= 3 etc. I would be pleased
if you could check out the latest snapshot and do some testing.

Christian

[1] http://files.basex.org/releases/latest/

On Thu, Aug 14, 2014 at 9:11 AM, Daniël Knippers <dknippers@gmail.com> wrote:
> Good morning,
>
> I wondered if there is room for optimization during the compilation of the
> following query:
>
> let $oneBillion := 1000000000
> for $x at $p in (1 to
> $oneBillion
> ) where $p = 1 return $x
>
> I would have expected this to be compiled into something like
>
> for $x in (1 to $oneBillion)[1] return $x
>
> Or simply
>
>
> (1 to $oneBillion)[1]
>
> Judging only from the execution times of the original query versus the
> optimized ones, it seems the sequence of 1 to one billion is entirely
> generated, which seems suboptimal in this case.
>
> Kind regards,
> Daniël Knippers