[mapserver-users] Layer rendering performance problem

Ben Madin lists at remoteinformation.com.au
Wed May 11 20:59:36 EDT 2011


I'm not sure whether it is still the case, but it used also to be that if you wanted to use the index, you need to name the shapefile without the .shp extension. If you used the .shp extension it wouldn't use the .qix index.

So maybe this is a question - Is that still the case?

On a similar note, does anyone know ... is the index created with shptree the same as the one created by QGIS (also a .qix file)?

cheers

Ben



On 12/05/2011, at 10:45 AM, mapserver-users-request at lists.osgeo.org wrote:

> From: Stephen Woodbridge <woodbri at swoodbridge.com>
> Date: 11 May 2011 11:53:34 PM AWST
> To: mapserver-users at lists.osgeo.org
> Subject: Re: [mapserver-users] Layer rendering performance problem
> 
> 
> look at the mapserver utilities:
> 
> shptree myshapefile
> 
> This creates a spatial index (*.qix) and you should create one for every shapefile you are using.
> 
> On Linux this will do the trick:
> 
> find /path/data -name \*.shp -exec shptree {} \;
> 
> If the .qix file is missing on every draw mapserver must create one on the fly in memory and the it throws it away.
> 
> -Steve W
> 
> On 5/11/2011 11:47 AM, Jon-Paul Dobson wrote:
>> Hi Jukka,
>> Thanks for getting back to me so quickly. No I haven't tried this. How
>> is this done and what is the benefit? Aren't Shape files already indexed?
>> Regards,
>> Jon-Paul.
>> 
>> On Wed, May 11, 2011 at 4:41 PM, Rahkonen Jukka
>> <Jukka.Rahkonen at mmmtike.fi <mailto:Jukka.Rahkonen at mmmtike.fi>> wrote:
>> 
>>    Hi,
>> 
>>    No answers but a question back. Have you created spatial index
>>    (.qix) for your shapefiles with shptree?
>> 
>>    -Jukka Rahkonen-
>> 
>>    Jon-Paul Dobson wrote:
>> 
>>     > Hi,
>> 
>> 
>> 
>>     > Whenever I display a layer based on a Shape file I notice that
>>    the Shape
>>    file is accessed constantly. This makes rendering extremely slow when
>>    compared to, for example, ESRI ArcIMS which appears to cache the
>>    Shape file.
>>    Is there an equivalent caching mechanism for Map Server? ArcIMS seems to
>>    render an order of magnitude faster when the number of symbols runs
>>    into the
>>    1000s
>> 
>> 
>> 
>>     > Similarly, whenever I display layer symbols using a truetype font
>>    I notice
>>    that the .ttf file is accessed for every symbol. This makes rendering
>>    appallingly slow. Is there also any caching mechanism to prevent this?
>> 
>> 
>> 
>>     > Any insight anyone can give would be much appreciated.
>> 
>> 
>>    Best regards,
>>    Jon-Paul.
>> 
>> 
>> 
>> 
>> _______________________________________________
>> mapserver-users mailing list
>> mapserver-users at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
> 

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