VS: [mapserver-users] Mapserver search performance

[Varun saraf]

Thanks a lot for the quick reply. I will give it a try.

On Mon, Apr 11, 2011 at 1:50 PM, Rahkonen Jukka
<Jukka.Rahkonen at mmmtike.fi> wrote:
> Hi,
>
> Shptree will help and stopwatch will tell you how much. Without spatial
> index Mapserver needs to go through the whole shapefile every time. Have
> a try, it will not take very many seconds to run shptree. Make different
> requests, take times with and without .qix files and you will some
> numbers. Change the requests and request order (query 1 with
> .qix/withour qix, query 2 without .qix/with .qix) so that you can see if
> you are actually testing the speed of disk access and memory cache
> access and not the effect of having spatial index.
> By adding DEBUG 5 for your layer you don't need stopwatch but you'll get
> timings into ms_errorfile.
>
>
> -Jukka Rahkonen-
>
> Varun saraf wrote:
>
>>
>> Hello Everyone,
>>
>> I have programmed a GIS application using Mapserver, Google maps and
>> Tilecache. The functionality of this GIS application is to extract the
>> data (from the dbf file) for all features (Points) within a randomly
>> drawn user shape and doing some statistical operation on that data. I
>> use an NQUERY mode with MAPSHAPE attribute to get all the data for the
>> user drawn shape. Mapserver takes aout 5-10 seconds for a small shape
>> (a couple of square miles) but as the shape gets bigger (hundreds of
>> square miles), the time taken to fetch all data related to the
>> features/points lying in the shape grows exponentially (Upto 2 hours
>> for some shapes). Until now, we were restricting the maximum area a
>> shape can have but we have to get rid of that. Is there a way to
>> improve the performance in any way? Will SHPTREE work for this
>> purpose? The features are currently points only but we may move to
>> polygons in future. We use the .shp files for the shapes. Is it
>> advantageous to move to a database instead? If yes, what database
>> works best?
>>
>> What I did notice is that for any given request to mapserver, however
>> large the shape, the CPU utilization never crosses 12%. Can we improve
>> performance by increasing the RAM or maybe move to a solid state hard
>> drive? There is also the possibility of moving this application to
>> Cloud computing. Anything that will improve the performance actually.
>> Can someone point me in the right direction as to what might be the
>> current bottleneck?
>>
>> T current setup is on windows and uses MS4W on an Apache server.
>>
>> Thanks,
>> Varun
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>>
>