I have a PostGIS table that was loaded from a shapefile which contained multipolygons. I've used v.external to connect to the shapefile directly and it displays fine. When I use the PG: driver to connect to the database table, the display crashes when I tell it to Zoom to the selected map extent. Looking at the underlying SQL commands that d.frame -e generates, it seems to be using a cursor to FETCH 500 records at a time, but keeps looping back and fetches the same 500 records over and over again. The display mechanism works fine using the PG: driver and a table that contains simple POLYGONS.
David A. Garbin Senior Fellow Noblis 3150 Fairview Park Dr S Falls Church, VA 22042 Phone: +1 703.610.2050 Cell: +1 703.795.6010 Email: [EMAIL PROTECTED] -----Original Message----- From: Garbin, David Sent: Wednesday, August 22, 2007 10:44 AM To: Garbin, David; Frank Warmerdam; Spencer Fogg Cc: grassuser@grass.itc.it Subject: RE: [GRASS-user] "Random read is not supported by OGR for this layer, cannot build support." We tried the patch to gdal that was suggested, but it did not work. The PostGIS table is owned by me and has a primary index, but the "Random read..." error is still reported. I worked around this by modifying the Vect_build_ogr method (found in lib/vector/Vlib/build_ogr.c) to remove the test. That solved this problem and the simple topology was built in GRASS with a link to the database. I had other problems displaying the table that I was working with, but I will report that in another thread. David A. Garbin Senior Fellow Noblis 3150 Fairview Park Dr S Falls Church, VA 22042 Phone: +1 703.610.2050 Cell: +1 703.795.6010 Email: [EMAIL PROTECTED] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Garbin, David Sent: Monday, August 06, 2007 3:52 PM To: Frank Warmerdam; Spencer Fogg Cc: grassuser@grass.itc.it Subject: RE: [GRASS-user] "Random read is not supported by OGR for this layer,cannot build support." We will pursue this route here at Noblis where Spencer worked over the summer. Our folks who installed the gdal libraries will be in touch, probably next week as we will be out of town this week. Thanks for your quick response. David A. Garbin Senior Fellow Noblis 3150 Fairview Park Dr S Falls Church, VA 22042 Phone: +1 703.610.2050 Cell: +1 703.795.6010 Email: [EMAIL PROTECTED] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Frank Warmerdam Sent: Monday, August 06, 2007 4:00 PM To: Spencer Fogg Cc: grassuser@grass.itc.it Subject: Re: [GRASS-user] "Random read is not supported by OGR for this layer, cannot build support." Spencer Fogg wrote: > Hi, GRASS users! I am a novice, and have only been using this program > for a couple of months now. I'm having a problem using GRASS with > postgres for a project at work, and I was wondering if you guys could help. > > > > I'm working with shapefiles, and want to display them in GRASS. Some of > these files are large enough to crash GRASS while cleaning, and even > more take longer to draw and redraw than I'd like. To avoid this, I'm > attempting to use v.external to connect to the files in a postGIS table, > created using shp2pgsql. When I run v.external, however, I get a strange > warning: "Random read is not supported by OGR for this layer, cannot > build support." Then when I try to display the created vector layer, > GRASS crashes. Spencer, On review of the OGR PostGIS driver I think this is a bug in the driver's "TestCapabilities" method. Are you in a position to rebuild your GDAL with a patch? I'd appreciate your filing a bug against GDAL/OGR for this issue, and we can pursue the discussion there. http://trac.osgeo.org/gdal/ Best regards, -- ---------------------------------------+-------------------------------- ------ I set the clouds in motion - turn up | Frank Warmerdam, [EMAIL PROTECTED] light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | President OSGeo, http://osgeo.org _______________________________________________ grassuser mailing list grassuser@grass.itc.it http://grass.itc.it/mailman/listinfo/grassuser _______________________________________________ grassuser mailing list grassuser@grass.itc.it http://grass.itc.it/mailman/listinfo/grassuser _______________________________________________ grassuser mailing list grassuser@grass.itc.it http://grass.itc.it/mailman/listinfo/grassuser