[mapserver-users] testing mapserver large files rendering improvements

[Guillaume Sueur]

Thanks for theses informations Jeff.
I'd like to suggest to emphasis the need of a .qix file a little bit 
more in the mapserver documentation. It's only explained in 'Utility 
Programs' Section and 'Optimizing vector data sources' doc, but the huge 
benefit of it (25 x faster in this case, but still 5x on small shapes) 
is not, IMHO, mentionned enough to make people use it on every shapefile.

Regards,

Guillaume


Jeff McKenna a écrit :
> Hello, comments inline below:
> 
> 
> On 15-May-08, at 9:27 AM, Guillaume Sueur wrote:
> 
>> Hi,
>>
>> I've just been doing few tests on mapserver trunk version to get an 
>> idea of how much the rendering of large shapefiles has been improved 
>> by paul's hacks on shx handler 
>> (http://blog.cleverelephant.ca/2008/04/see_30.html)
>>
>> My shapefile is 1 208 668 features, 160 Mo for the .shp file itself 
>> with a .shx of 5.2 Mo
>>
>> here are the times for a 5x5 km map to be drawn with shp2img, in PNG 
>> (no AGG)
>>
>> NO QIX :
>> mapserv 5.0.2 : 0.680 s
>> mapserv trunk : 0.699 s (!)
>>
>> WITH QIX :
>> mapserv 5.0.2 : 0.124 s
>> mapserv trunk : 0.027 s
>>
>>
>> it looks like if the improvement only appears with use of a .qix file, 
>> which is highly recommended but sometimes forgotten.
>> Has anyone had the same kind of experiment ?
> 
> yes: http://lists.osgeo.org/pipermail/mapserver-dev/2008-April/007170.html
> 
>>
>>
>>
>> By the way, I noticed that it doesn't seem mandatory anymore to write 
>> the mapfile's DATA statement without the .shp extension to make use of 
>> the .qix file, as the results are strictly identical on mapserver 
>> trunk if I write "streets.shp" or "streets". Can someone confirm that ?
>>
> 
> Confirmed.  This was fixed recently (ticket: 
> http://trac.osgeo.org/mapserver/ticket/590), verified, and documentation 
> was updated.  Therefore the next release of MapServer will no longer 
> require you to omit the '.shp' for the DATA parameter for .qix use.
> 
> -jeff
> 
> 
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