[Mapserver-users] Slow MapServer with large data

[Vincent Schut]

Another remark: mind the resolution / amount of detail of your data.
e.g. I have some river shape files for entire indonesia, that are *very* 
detailed (and large indeed: 30 Mb) and if draw a map of indonesia as a whole, 
this layer takes a lot of time to draw...
If this is so, you should simplify your data for use at certain zoom levels, 
and use minscale/maxscale to select the right reduced data file. I think 
there are arcview / arcinfo tools for that. Or you can use postgis and 
download the simplify function that implements the DP-algorithm 
(http://cobalt.rmnet.it/~san/postgis/simplify/simplify-0.2.tgz).

My 2 cents.
Vincent.

On Tuesday 13 May 2003 15:13, pkishor_98 wrote:
> --- In mapserver-users at yahoogroups.com, jankarin at p... wrote:
> > I have tried on af few shapefiles, but it doesn't help much. And it
>
> wouldn't have any effect on our tab-data.
>
> > By the way: Is 15 sec. for a 25 MB shapefile/40 sec for a 30 MB
>
> MapInfo map-file the usual speed for MapServer on a PIII, 650 Mhz, 262
> MB RAM ?
>
> sorry... just jumping in. 15 secs us way too much for anything (in my
> opinion). I have as big or bigger files running on a beatup 1 Ghz
> Duron box (that is like a Celeron, not a PIII, in Intel-speak) with
> 128 Mb ram. Usually it takes a couple or 3 or 4 secs to return.
>
> Here are my rough benchmarks -- pure db queries should be returned to
> the completely formed web page in sub-second (a few hundred
> microseconds usually). Mapserver queries should not exceed 5 secs
> (5000 microsecs). After that I start worrying about performance.
>
> As Steve said, judicious use of shptree goes a long way.
>
> > If it is, there's only one thing to do,  if not .....
> > Anyone have some ideas?
> >
> > Jan
> >
> > woodbri at s... wrote:
> > > Have you built shptree indexes for all your shapefiles?
> > >
> > > On 9 May 2003 at 13:14, jankarin at p... wrote:
> > > > Hello
> > > >
> > > > I have a little problem with the speed in MapServer.
> > > > We're trying to make qiuck-viewer to shape- and
> > >
> > > tab-formats, but
> > >
> > > > MapServer is running slow with large data: 20 seconds:
> > >
> > > Shapefil 17 MB,
> > >
> > > > dbf-fil 9,5 MB. 45 seconds: Map-fil 31 MB, Dat-fil 25 MB.
> > > >
> > > > I have been trying with the GCI-version and PHP Mapscript
> > >
> > > - same
> > >
> > > > result.
> > > >
> > > > I am running MapServer 3.6.4 with PNG-output under Apache
> > >
> > > 2.4.5 on
> > >
> > > > Windows 2000. The pc is Pentim III, 650 Mhz, 262 MB RAM.
> > > >
> > > > In another installation (PII, 400 Mhz, 196 MB RAM) a
> > >
> > > shapefile
> > >
> > > > (shapefile 17 MB, dbf-fil 9,5 MB) took 80 seconds to
> > >
> > > show.
> > >
> > > > We're using MapServer in an application which is
> > >
> > > dynamically creating
> > >
> > > > map-files with Mapscript (only showing one layer at a
> > >
> > > time). We're
> > >
> > > > talknig about 17.000 layers in shape- and tabformats, so
> > >
> > > it is not
> > >
> > > > possible to improve indexfiles or anything else related to
> > >
> > > a single
> > >
> > > > layer.
> > > >
> > > > Can anyone help?
> > > >
> > > > Thanks,
> > > >
> > > > Jan Christiansen
> > > > jankarin at p...
> > > > Engineering College of Copenhagen
> > > >
> > > > _______________________________________________
> > > > Mapserver-users mailing list
> > > > Mapserver-users at l...
> > > > http://lists.gis.umn.edu/mailman/listinfo/mapserver-users
> >
> > _______________________________________________
> > Mapserver-users mailing list
> > Mapserver-users at l...
> > http://lists.gis.umn.edu/mailman/listinfo/mapserver-users
>
> _______________________________________________
> Mapserver-users mailing list
> Mapserver-users at lists.gis.umn.edu
> http://lists.gis.umn.edu/mailman/listinfo/mapserver-users

-- 
______________________________________
Vincent Schut
Sarvision B.V.
Wageningen, The Netherlands
www.sarvision.com