ArcSDE and SLD WMS (attribute queries)

[John Fletcher]

Bart,

The Government of BC has an application which uses non-spatial filters
in SLD documents to Mapserver, with an SDE back-end:
http://openmaps.gov.bc.ca/imfows13/imf.jsp?site=idt
Find Imagery --> Air Photos --> Search For Air Photos
Zoom in to the resultant features, activate the "Centres" tool, and draw
a box around a number of Air Photo centre points.  This will show three
separate SDE layers styled using an SLD with a filter (non-spatial), two
of which have alternate symbolization and thus a more complex filter
clause in the SLD.

Incidentally, the other imagery types (Orthophotos, Satellite Imagery,
etc) are primarily backed by shapefiles, so are not relevant to this
discussion.

I did run into timeout problems getting the SLD to work when there were
> 200 or so individual features that needed to be identified with the
filter.  I had been using a single PropertyIsEqualTo clause for each
feature which I was able to change to a handful of PropertyIsBetween
clauses due to the convenient sequential numbering of the ID values
which I was filtering.  This change allows the SLD filter to work quite
well.

Regards,

John Fletcher
Latitude Geographics Group Ltd.
jfletcher at latitudegeo.com www.latitudegeo.com
Head Office: 204 Market Square Victoria, BC Canada V8W 3C6
Tel: (250) 381-8130 Fax: (250) 381-8132 

Geocortex Internet Mapping (www.geocortex.net) - Helping people succeed
with web-based geography


-----Original Message-----
From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] On
Behalf Of Bart van den Eijnden (OSGIS)
Sent: Tuesday, March 13, 2007 2:29 AM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: [UMN_MAPSERVER-USERS] ArcSDE and SLD WMS (attribute queries)

Hi list,

using Mapserver on ArcSDE and trying to apply an SLD with a Filter I run
into internal server errors all the time after about 30 seconds.

My reasoning is that this is since the query-by-id mechanism will query
ArcSDE for each item of the resultset and this just won't work.

So can I safely conclude Mapserver on ArcSDE won't work well for
non-spatial queries?

I am using FastCGI already. Using cgi crashes as well, but after a
longer period of waiting time (minutes).

Best regards,
Bart

--
Bart van den Eijnden
OSGIS, Open Source GIS
http://www.osgis.nl