[GRASSLIST:10788] Re: How can I reduce the loading time of GRASS-layers in UMN Mapserver

[wqual]

Hi Radim,
thanks for your reply. 
Am Dienstag 07 März 2006 pH:44:09 vormittags schrieb Radim Blazek:
> GRASS does not save spatial index in file becouse it
> occupied too much space and spatial index is used only occasionly.
This means that it is possible to create this spatial index? 
> So spatial index could make it slower but 6 times seems too much.
>
> My guess is that it is caused by attributes. Try to go to the
> vector directory in GRASS and rename temporarily 'dbln' file.
Ok. Loading time decreased significantly. But no dbln, no queries (or am I 
wrong?). Mapserver-Maps should be queriable _and_ fast. 
>
> Also for testing to avoid the difference between nature
> of topological and SF format try to test with points or lines.
I did not test this by now.

Best regards,

Wolfgang

---8<-----------------
>
> Radim
>
> On 3/6/06, Wolfgang Qual <Wolfgang.Qual at gmx.net> wrote:
> > Dear list,
> > I created a mapfile for two identical themes: One of them is a shapfile,
> > the other one is a grass vector dataset. The shapefile contains a
> > *.qix-file which was created using the program shptree.
> > I compared the loading time for the two themes using the command "time
> > wget -O /dev/null "http://path/to/the.map". Result: the grass theme took
> > about 12 seconds (on a local machine), shapefile only 2s.
> > My Question therefore: is there a possibility to speed up grass layers in
> > the mapserver application (something like shptree does?)? The attribute
> > table of the grass-theme is a (default) dbf-file.
> >
> > Declaration of the grass-layer in the mapfile:
> >
> > # OGR-Layer aus GRASS
> > #_# START LAYER l8
> > LAYER  NAME "l8"
> > TYPE polygon
> > STATUS ON
> >     CONNECTIONTYPE OGR
> >     CONNECTION
> > "/home/wqual/grassdata/muenchen/stadtbezirk/vector/block/head"
> >     DATA "1"
> >     METADATA
> >       LTITLE "l8"
> >     END #metadata
> > ### TYPE Polygon -- LEGTYPE 0x01 -- SYMTYPE 0x02
> > ### singlepolyleg
> >    CLASSITEM "cat"
> >    CLASS NAME "Block_GRASS"
> >     COLOR 255 0 0
> >     OUTLINECOLOR 20 200 10
> >    END #CLASS
> > #_# LAYER l8 QUERY
> > END # LAYER l8
> >
> > I would be very happy to receive some hints/tips on this issue.
> >
> > Best regards,
> >
> > Wolfgang
> >
> > --
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