[postgis-users] RE: help with subsetting large polygon datasets

[Menke, Kurt]

Chris,
The problem dataset is landownership for the state of New Mexico.  It has
18,000 polygons and some are large complex polygons with holes in them
(there are large private parcels with small chunks of State lands within).
The bounding box generally will be selecting around 1,000 polygons and takes
around 3 minutes to run including the export to shapefile. 
 
For comparison the statewide roads layer has 600,000 records and a similar
bounding box will select around 10,000 records.  This only takes around a
minute.
 
We are using spatial indices and have been good about performing regular
vacuums.
 
Kurt 
 
~~~~~~~~~~~~~~~~~~~~~~~~~
Kurt A. Menke
GIS Analyst/Programmer
 
Mailing Address  
Earth Data Analysis Center 
MSC01 1110 
1 University of New Mexico 
Albuquerque, New Mexico  87131-0001 
 
Street Address
University of New Mexico
Bandelier West, Room 123
Albuquerque, NM 87131
 
Phone:  (505) 277-3622 (ext. 239) 
FAX:  (505) 277-3614 
email:  kmenke at edac.unm.edu
 
 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20040204/dbc468b2/attachment.html>