【转帖】database searching - other method
 

database searching - other method
database searching - other method
hi,
is it possible (or will it be) to iterate database elements in other way than using iterators? or, can i create my own iterator, using, for example some index-like structure to get, for example, only "polylines with vertices in rectangle [x1,y1]x[x2,y2]"? then, drawing engine, when drawing is zoomed, would not loose time for iterate elements that aren't in sight. i know that i can make my own index and use it in my own functions, but i want to library know about it and use it instead of regular iterator, when i want.
tia
there are some selection sets working, but iterators are fast.
you can afford to call them at any redraw (if the graphics is not cached), and to exclude the items not in the current viewport settings - probably by using getgeomextents()
regards
chudomir