Re: [boost] RTL

From: Arkadiy Vertleyb (vertleyb_at_[hidden])
Date: 2005-10-18 15:42:54

"Calum Grant" <calum_at_[hidden]> wrote

> > This sounds like a correct result -- can I see the first 50 items?
>
> The output is at the bottom.

This result is not sorted by (counter, city) as requested, which makes it
impossible to compare it with mine.

> I've managed to get my times down a bit by reimplementing the solution
> in a much more straightforward way.  I can insert all 21421 items,
> calculate the number of neighbours, and display the top 500 in 235ms.
> Then I can remove 1982 items,

from where?

> and redisplay the results, in 47
> milliseconds.  This of course makes me suspicious that I'm doing
> something wrong.........

This numbers are very impressive, but they don't tell much unless Jose runs
it on his setup (after the result is properly sorted).

> The solution I have is not terribly elegant from RML's point of view,
> since as I said before RML is designed for logical queries rather than
> numerical computation.  It was not a terribly interesting problem
> because it needed just a single table with two indexes.

Hmm, I managed to program it in RTL as a single relational view on the
original table, without doing _anything_ by hand.  The correctness of this
view is preseved by the library when the data is changed.  In your case
_you_ remove 1982 items.  In my case _the library_ removes 1982 items.  I
think your solution is rather by-hand than RML-based.

Can you create a single RML query on the original table that solves the
problem?  Can you claim that using RML added a lot to your solution?  Is it
faster/more elegant/readable/etc.  than just using STL directly?

Regards,
Arkadiy