[mapserver-users] Problem with attribute query, multiple attributes

Bistrais, Bob Bob.Bistrais at maine.gov
Thu Nov 29 06:44:59 PST 2012


Thanks Jeff.  That link shows how to build an index on a shapefile.  Is there an equivalent for File GDB?  I'm looking at the GDAL document for GDB now, not seeing an index description.

-----Original Message-----
From: Jeff McKenna [mailto:jmckenna at gatewaygeomatics.com] 
Sent: Wednesday, November 28, 2012 6:41 PM
To: mapserver-users at lists.osgeo.org
Subject: Re: [mapserver-users] Problem with attribute query, multiple attributes

On 12-11-28 5:43 PM, Bistrais, Bob wrote:
> I am trying to set up an attribute query for a large parcel dataset 
> (about 550,000 polygons).  I am having trouble with the query 
> exceeding the 30 second limit.
> 
>  
> 
> I am trying to query on the map_bk_lot and town attributes.  I can 
> query on either one separately and get results, but I need to query on 
> both at the same time.
> 
>  
> 
> Here is my query expression:
> 
> $queryExp = "('[TOWN]' == '007-042') AND ('[TOWN]' == 'Acton'))";     
> ---Hardcoded for testing now, will eventually use variables
> 
> $pLayer->queryByAttributes("MAP_BK_LOT",$queryExp,MS_SINGLE);   
> ----Query statement
> 
>  
> 
> The data is in an ESRI File GDB.  I am using MS4w 3.0.4m MapServer 
> 6.0.2, MapScript 6.1 for PHP
> 
>  
> 
> One other thing worth mentioning- if I use a small subset of features 
> (such as a town), the query will work without timing out.  But I'm no 
> longer convinced that dataset size is the problem since it will query 
> on one attribute.
> 
>  
> 
> Any ideas what's going wrong here?

A tip that might come in handy someday, if not in this case, could be to create an "attribute index" on your vector field (see example in http://www.gdal.org/ogr/drv_shapefile.html); I've done this before and it's improved attribute queries in MapServer significantly.  You can generate one through an ogrinfo command with the "sql" switch.

Sorry I cannot provide exact FileGDB examples at the moment.

-jeff



--
Jeff McKenna
MapServer Consulting and Training Services http://www.gatewaygeomatics.com/






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