> yes, but there is room to improve performance
> in this particular case for example, if you add an index
> on (X1_Y1, X1_Y2, X1_Y3)
> and rewrite the query like this :
>
> where
> x1_y1 in (...)
> x1_y2 >= ? - 20 and
> x1_y2 <= ? + 20 and
> x1_y3 >= ? - 20 and
> x1_y3 <= ? + 20 and
> x1_y4 >= ? - 20 and
> x1_y4 <= ? + 20 and
> x1_y5 >= ? - 20 and
> x1_y5 <= ? + 20;
>
> it perform better
> but we should certainly have even better performance with indexes like R*tree (Postgresql use Gist, but I did not tested it yet with a case like that, MssQL use kind of grid http://technet.microsoft.com/en-us/library/bb964712.aspx)
>

yes it's amazing, with this trick, from 150 ms i go down to 30 ms !!

stéphane