[Mapserver-users] limiting query results

Thu Mar 13 14:52:30 EST 2003

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I'm already doing this to some extent, but a box in the rural areas may
return a couple dozen properties, where the same box at the same scale in an
urban area bogs down.

Adam

-----Original Message-----
From: Fawcett, David [mailto:David.Fawcett at state.mn.us]
Sent: Thursday, March 13, 2003 11:32 AM
To: mapserver-users at lists.gis.umn.edu; 'Ryan, Adam'
Subject: RE: [Mapserver-users] limiting query results

For the instance of the user selecting the whole county with the box, could
you use scale-dependent layers so they don't have the option to query the
whole county.   

I am sure that there is a more elegant solution, but this could prevent the
crash you are describing. 

David.

David J. Fawcett
GIS / Databases

MN Office of Environmental Assistance
520 Lafayette Rd N
St. Paul, MN 55155
651.215.0200

> ----------
> From: 	Ryan, Adam[SMTP:ARyan at co.linn.or.us]
> Sent: 	Thursday, March 13, 2003 1:02 PM
> To: 	mapserver-users at lists.gis.umn.edu
> Subject: 	[Mapserver-users] limiting query results
> 
> 
> Dear List, 
> 
> I'm resending this because I can't find a cgi (not mapscript) solution. 
> 
> I want to limit the number of records returned by an NQUERY or and
ITEMNQUERY, or the number of times mapserv sends the layer template.  If the
user makes a box around the whole county, or searches by [STREETNAME] =~
/ST/, for example, mapserv easily and quickly renders the image, but then
spits out the layer template many thousands of times and ultimately crashes
the browser.
> 
> I can monitor the [rn] and take steps using javascript, but I can't stop
mapserv from spitting out all the instances of the template.
> 
> I can't use MAXFEATURES because that limits the number of records that are
searched, not the number returned. 
> 
> Any ideas? 
> 
> Adam Ryan 
> Linn County 
> 
> 
> 

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<P><FONT SIZE=3D2>I'm already doing this to some extent, but a box in =
the rural areas may return a couple dozen properties, where the same =
box at the same scale in an urban area bogs down.</FONT></P>

<P><FONT SIZE=3D2>Adam</FONT>
</P>

<P><FONT SIZE=3D2>-----Original Message-----</FONT>
<BR><FONT SIZE=3D2>From: Fawcett, David [<A =
HREF=3D"mailto:David.Fawcett at state.mn.us">mailto:David.Fawcett at state.mn.=
us</A>]</FONT>
<BR><FONT SIZE=3D2>Sent: Thursday, March 13, 2003 11:32 AM</FONT>
<BR><FONT SIZE=3D2>To: mapserver-users at lists.gis.umn.edu; 'Ryan, =
Adam'</FONT>
<BR><FONT SIZE=3D2>Subject: RE: [Mapserver-users] limiting query =
results</FONT>
</P>
<BR>

<P><FONT SIZE=3D2>For the instance of the user selecting the whole =
county with the box, could you use scale-dependent layers so they don't =
have the option to query the whole county.&nbsp;&nbsp; </FONT></P>

I am sure that there is a more elegant solution, but =
this could prevent the crash you are describing.

<P><FONT SIZE=3D2>David.</FONT>
</P>
<BR>

<P><FONT SIZE=3D2>David J. Fawcett</FONT>
<BR><FONT SIZE=3D2>GIS / Databases</FONT>
</P>

MN Office of Environmental Assistance
 520 Lafayette Rd N
 St. Paul, MN 55155
 651.215.0200

&gt; ----------
 &gt; From: =
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Ryan, =
Adam[SMTP:ARyan at co.linn.or.us]
 &gt; Sent: =
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Thursday, March 13, 2003 =
1:02 PM
 &gt; To: &nbsp; =
mapserver-users at lists.gis.umn.edu
 &gt; Subject: &nbsp;&nbsp;&nbsp;&nbsp; =
[Mapserver-users] limiting query results
 &gt; 
 &gt; 
 &gt; Dear List, 
 &gt; 
 &gt; I'm resending this because I can't find a cgi =
(not mapscript) solution. 
 &gt; 
 &gt; I want to limit the number of records returned =
by an NQUERY or and ITEMNQUERY, or the number of times mapserv sends =
the layer template.&nbsp; If the user makes a box around the whole =
county, or searches by [STREETNAME] =3D~ /ST/, for example, mapserv =
easily and quickly renders the image, but then spits out the layer =
template many thousands of times and ultimately crashes the =
browser.

<P><FONT SIZE=3D2>&gt; </FONT>
<BR><FONT SIZE=3D2>&gt; I can monitor the [rn] and take steps using =
javascript, but I can't stop mapserv from spitting out all the =
instances of the template.</FONT></P>

&gt; 
 &gt; I can't use MAXFEATURES because that limits the =
number of records that are searched, not the number returned. 
 &gt; 
 &gt; Any ideas? 
 &gt; 
 &gt; Adam Ryan 
 &gt; Linn County 
 &gt; 
 &gt; 
 &gt;

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