Big areas == slow and problematic zoom? (was street level zoom performance)

[Rodrigo Del C. Andrade]

    Hello dear list.

    First of all, thanks immensely for all the tips with the last issue 
I presented (streets and its labels drawing performance). This however 
brings me to a new issue.
     I created index files (with shptree) for all the layers and tuned 
them for maximum speed, however I found out using Debug On that a single 
layer was responsible for the 99% of the drawing time: country polygon 
layer. The debug log was looking like this when I tried to zoom in close 
enough to see neighborhoods (just an example):

     msDrawMap(): Layer 1 (COUNTRY), 189.021s   <<----
     msDrawMap(): Layer 1 (city1-limiters), 0.067s
     msDrawMap(): Layer 4 (city1), 0.041s
     msDrawMap(): Layer 3 (city1_annotation), 0.025s
     msDrawMap(): Layer 1 (city2-limiters), 0.085s
     msDrawMap(): Layer 4 (city2), 0.047s
     msDrawMap(): Layer 3 (city2_annotation), 0.023s

    Removing the offending layer solves all my performance problems, but 
I am left with an archipelago instead of a state :D
    We've done some tests:
     - creating a square polygon shape with roughly the size of South 
America causes the problem,
     - using a square polygon shape the size of a city does not.
   
    The country and world shapes we are/were using as a base to drawn 
our cities on top came from the ESRI ArcGIS 9 Media kit, so I doubt they 
are out of specification (they created the shape file specs anyway, 
haven't they?).
    So I guess my question is: does a big area polygon takes longer to 
render at higher zoom levels and thats the expected behavior and I must 
find a way to turn off these layers when I zoom in too close (risking 
having some cities appearing to be islands mid sea), or is there 
something wrong with my setup?
    Btw, I am using Java Mapscript 4.10.1 on linux.

     Thanks again for all the support so far, you guys rock.
 
-- 

*Rodrigo Del C. Andrade*
/Programador/
/SIC - SSE - Soluções Segurança Pública/

*DÍGITRO TECNOLOGIA*
*E-mail:* rodrigo.andrade at digitro.com.br 
<mailto:rodrigo.andrade at digitro.com.br>
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