[Mapserver-west] postgis query size limit

[Aaron Racicot]

Ken-ichi,

I am not to sure on the PostGIS question although Daniel seems to hint
at a static buffer overflow in the old mail thread.  I assume you can
not just make multiple layers to get around the problem because you want
all of the points to be defined in one layer on the map?  Are you using
Mapscript or the CGI version of Mapserver?  Can you do a similar query
(with more than 400 items in the where clause) straight to the database,
like via a simple PHP program?  Can you narrow down whether it is a
Mapserver problem or a PostGIS problem?  If it is PostGIS (doesn't sound
like it) then you might want to post the question to the PostGIS mailing
list; they might have an answer for you on the limitation you seem to be
hitting.  You might want to just post to the main Mapserver mailing list
again as well and ask if there has been any resolution.  All of my
PostGIS queries tend to have a much shorter WHERE clause!

As far as the conference goes, yes I am attending and I mentioned in a
previous email that I would love to make an effort to really get to know
all of the Mapserver-west folks out there.  Let's definitely make an
effort to meet up at the social events or maybe even plan a dinner for
the group.

Aaron

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| Aaron Racicot  | aaronr at ecotrust.org   |
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-----Original Message-----
From: mapserver-west-bounces at lists.maptools.org
[mailto:mapserver-west-bounces at lists.maptools.org] On Behalf Of Ken-ichi
Sent: Thursday, May 12, 2005 4:17 PM
To: mapserver-west at lists.maptools.org
Subject: [Mapserver-west] postgis query size limit

Hi all.  I've been having trouble using very long PostGIS queries within

MapServer.  I found this year-old email on the same topic

http://lists.gis.umn.edu/pipermail/mapserver-users/2004-February/010233.
html

and I was wondering if anyone knows if this problem has been fixed.

My situation is as follows: I'm in an awkward bind in which all the 
non-spatial parts of a dataset reside in a MySQL database, and all the 
spatial stuff is in PostGIS.  When a user queries the MySQL db, they get

back a bunch of unique record identifiers that can then be used to pull 
point data out of the PostGIS table by setting a really long WHERE 
clause (ie 'WHERE key=value1 OR key=value2 OR key=value3, etc).  All 
well and good, until I start trying to pull out more than about 400 
records.  Then MapServer chokes and I get a 500 error.

If anyone can think of a better way around this problem, I'm all ears. 
Thanks.

-Ken-ichi

PS.  Anyone going to Open Source Geospatial '05?  I just registered.
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