[mapserver-users] Layer rendering performance problem

[Jon-Paul Dobson]

Hi,

I just tried creating a qix file as suggested and found that the Shape file
now renders 22 times faster! Fantastic advice guys. Many thanks.

If only there was a way to prevent the TTF file being continuously accessed
when displaying a symbol using a truetype font. Any further ideas at all? It
kind of makes a TTF unusable.

Best regards,
Jon-Paul.

On Thu, May 12, 2011 at 7:52 AM, Rahkonen Jukka
<Jukka.Rahkonen at mmmtike.fi>wrote:

>  Hi,
>
> For clarification, it used to be rather a long time ago that the index file
> (.qix) was not utilised even it was present in the data folder if the LAYER
> DATA was given as
> DATA "C:\Data\WMS_DATA.shp"
>
> Index was used only if the LAYER DATA was like
>  DATA "C:\Data\WMS_DATA"
>
> However, this in old knowledge and both WMS_DATA.shp and WMS_DATA are
> utilising the index nowadays.
>
> Gdal is using the same .qix index file system and therefore also QGIS.
> There is more info about gdal shapefile spatial index in
> http://www.gdal.org/ogr/drv_shapefile.html
> The page tells also that native ESRI spatial index files (.sbn/ .sbx)  are
> not supported.
>
> -Jukka Rahkonen-
>
>
>
>  ------------------------------
> *Lähettäjä:* mapserver-users-bounces at lists.osgeo.org [mailto:
> mapserver-users-bounces at lists.osgeo.org] *Puolesta *Ben Madin
> *Lähetetty:* 12. toukokuuta 2011 4:00
> *Vastaanottaja:* mapserver-users at lists.osgeo.org
> *Aihe:* Re: [mapserver-users] Layer rendering performance problem
>
>   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.orgwrote:
>
>  *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<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.
>
>
>
>
>
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