I might suggest the following: 1. pack the table, that may solve the empty object problem, but there are issues with packing if you use ROWID as a key field. 2. The 199 or 201 problem maybe a matter of precision; many posts on this, but basically, the object really is 200 meters, it just cant find a virtual grid point to land on, so it measures off, but the underlying data really is right. You may fix this with a bounded projection. 3. I suggest you buffer into a new table, not the base table- the editable layer always gets the buffer object even it the target objects are in another layer. If you are using the buffers for a spatial query, it will run faster with only the buffers. Pay attention to the data aggregation when buffering, you can select the values from the base table to assign, by field, to the buffer table (I think that is available in 6.5). Your buffer table could hold only a Key field to relate to the base table, or part/all of the data, but may perform best with only a key field. Index the key field in both tables. 4. If there is not a key field, add a field to hold ROWID, update it, and separate the table into sections to buffer on. 7 queries of 10,000 objects, then Buffer each selection. If you have a separate table to hold the buffer objects, each section of the base table you buffer will append to the buffer table. If there is an offensive record that didn't pack out, you will begin to have a way to find it by halving the problem section until you weed out the problem record.
William "Woody" Woodruff Zoning Administrator Charter Township of Union, Isabella County, Michigan -84.80947000 43.61095100 2010 S Lincoln Rd, Mt. Pleasant, MI 48858 (989) 772 4600 EXT 41 Visit our web site at http://www.geocities.com/ctuzoning/index.htm -----Original Message----- From: Silke Keuerleber [mailto:[EMAIL PROTECTED] Sent: January 27, 2004 04:27 To: 'MapInfo-L' Subject: MI-L problem with buffer() function Hello everybody, I want to buffer around 70000 region objects, but some of the regions just don't accept a specific buffer width. One region for example can be buffered with 199 meters or with 201 meters, but not with 200 meters. I have tried a couple of buffer widths and with every width I tried at least one region led to an error. Has anyone experienced similar problems with buffering regions in MapInfo 6.5? Can anyone offer any solutions? The error message tells me that I "Can't update an empty database object" Thank you for your help Silke Keuerleber PTV AG Mobility Systems GIS Data Engineering Tel.: +49 7 21 96 51- 465 Fax: +49 7 21 96 51- 688 E-Mail: [EMAIL PROTECTED] ____________________________ PTV Planung Transport Verkehr AG Stumpfstrasse 1 76131 Karlsruhe Germany http://www.ptv.de http://www.reiseplanung.de http://www.varta-guide.de http://www.cityguidefinder.de --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 10109
