Ang. RE: [MI-L] Number of fields
I stand corrected - I confused this with the 4 GB limit for files on FAT volumes, which of course is a more or less obsolete factor. Out of academic interest: Why is it a MapInfo limitation? Does it fall into the same box as the print size limitation, i e a wish to provide backward compatibility for older Windows versions? As I've said before, I think this it's sad that they feel it necessary to limit the evolution of the program because of such concerns, especially since there obviously are a lot of users who don't care to upgrade anyway and are quite happy with older MapInfo versions. Hälsning / Best regards Mats.E FB Engineering AB Södra Förstadsgatan 26 211 43 Malmö Tel: 040-660 25 50 Mobil: 0705-27 60 27 Fax: 040-660 25 99 [EMAIL PROTECTED] www.fbe.se Uffe Kousgaard [EMAIL PROTECTED] Sänt av: [EMAIL PROTECTED] 2006-01-24 11:47 Till Mapinfo-L mapinfo-l@lists.directionsmag.com Kopia Ärende RE: [MI-L] Number of fields From: Mats Elfström [EMAIL PROTECTED] I think your analysis is correct. I believe the numbers are as follows: Max Tab file size: 2 GB (OS limit, not MapInfo) It is a MapInfo limit, since even Windows with NTFS filesystem has the 2 GB limit. I tried to enter it into the Wiki: http://www.mapinfo-l.com/Wiki/TABFormat Regards Uffe ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
Re: [MI-L] Number of fields
Hi, I just tested this: You can add a Logical field until you reach 250 fields (at least MI800). If you try this with a Char (254) you can only have 15 ! MI gives a note that a record lenght can't exceed 4000 bytes. Venligst Søren Breddam Stevns Kommune - www.stevns.dk Vallø-Stevns fusion: www.valloe-stevns.dk * Tlf.: 5656 1891 * Mob.:2895 3034 -Oprindelig meddelelse- Fra: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] vegne af Bill Thoen Sendt: 23. januar 2006 23:20 Til: mapinfo-l@lists.directionsmag.com Emne: Re: [MI-L] Number of fields Paul Middleton writes: What is the limitations on the number of fields you can have in any one layer/table, if so what are they and does the version of MI make any difference. In an old MapInfo Users guide, the Frequently Asked Questions section in the Appendix says it's 255. But IMHO, if you ever get up to needing that many fields in your table, you probably ought to re-examine your data structure and ask your self if it's as normalized (from a DBMS point of view) as it should be. ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
RE: [MI-L] Number of fields
Hi all, I had some problem with a table with a lot of fields, but... i suppose there is no limit on number of fields, but only limit to 4096 byte on the total sum of name of fields. Massimo ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
RE: [MI-L] Number of fields
Yes, hopeless, isn't it? When many people need to consider all of their data (the non-spatial stuff) in the context of its spatial location, and when that data may be disposed in numerous well-normalized tables elsewhere in the enterprise, having these sorts of limits is insane. Even with the expensive middleware, it's a poorly-designed system. It makes MI seem like a toy that has outgrown its relevance. IL Thomas GeoSciSoft - Perth, Australia -Original Message- From: [EMAIL PROTECTED] [mailto:mapinfo-l- [EMAIL PROTECTED] On Behalf Of Søren Breddam Sent: Tuesday, January 24, 2006 3:59 PM To: Bill Thoen; mapinfo-l@lists.directionsmag.com Subject: Re: [MI-L] Number of fields Hi, I just tested this: You can add a Logical field until you reach 250 fields (at least MI800). If you try this with a Char (254) you can only have 15 ! MI gives a note that a record lenght can't exceed 4000 bytes. Venligst Søren Breddam Stevns Kommune - www.stevns.dk Vallø-Stevns fusion: www.valloe-stevns.dk * Tlf.: 5656 1891 * Mob.:2895 3034 -Oprindelig meddelelse- Fra: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] vegne af Bill Thoen Sendt: 23. januar 2006 23:20 Til: mapinfo-l@lists.directionsmag.com Emne: Re: [MI-L] Number of fields Paul Middleton writes: What is the limitations on the number of fields you can have in any one layer/table, if so what are they and does the version of MI make any difference. In an old MapInfo Users guide, the Frequently Asked Questions section in the Appendix says it's 255. But IMHO, if you ever get up to needing that many fields in your table, you probably ought to re-examine your data structure and ask your self if it's as normalized (from a DBMS point of view) as it should be. ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 267.14.22/238 - Release Date: 23/01/2006 ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
RE: [MI-L] Number of fields
From: Mats Elfström [EMAIL PROTECTED] I think your analysis is correct. I believe the numbers are as follows: Max Tab file size: 2 GB (OS limit, not MapInfo) It is a MapInfo limit, since even Windows with NTFS filesystem has the 2 GB limit. I tried to enter it into the Wiki: http://www.mapinfo-l.com/Wiki/TABFormat Regards Uffe ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
Re: Ang. RE: [MI-L] Number of fields
Hi Mats The 2 GB limit is a MapInfo limit and NOT an OS limit. Even under Fat32 you can have files up to 4 GB and under NTFS you can have files up to 16 Terrabytes. MapInfo is limited in this way because they use a signed 32 bit long as a pointer to the Map File. I have created a new 64 bit file format and have tested this with full National Coverage of Great Britain. We have information on this at: http://www.GBplc.co.uk I have used this on FAT 32 and so can confirm the 4 GB limit. I have also tested up to 12 GB files under NTFS. I would need an even larger data set to go above this. I am working on a TAB to GZ convertor so if anyone has large datasets they would like to test keep an eye on GBplc.co.uk for the new free TAB to GML(compressed to GZ) as well as free GML(compressed to GZ) to BIG ( 64 bit format). Regards Bob @www.MapsByDesign.co.uk In message [EMAIL PROTECTED] e.se, Mats Elfström [EMAIL PROTECTED] writes Hi Dave! I think your analysis is correct. I believe the numbers are as follows: Max field length: 255 bytes Max number of fields: 255 (as someone pointed out, if you need that many, it's bad database design) Max length of record: ~4000 bytes (quickly reached if you join in some Access tables) Max Tab file size: 2 GB (OS limit, not MapInfo) I have noted on some occasions that some data tables have very long character fields, 255 bytes. I believe this data to be of Access origin, and originally were memo fields which have no limit length in Access. As the DB structure of MI cannot handle memo fields they probably get the max character field length when put into the MI DB format. Imagine what will happen if you have a number of such fields, the 4000 byte barrier is reached very quickly. Hälsning / Best regards Mats.E FB Engineering AB Södra Förstadsgatan 26 211 43 Malmö Tel: 040-660 25 50 Mobil: 0705-27 60 27 Fax: 040-660 25 99 [EMAIL PROTECTED] www.fbe.se David Baker [EMAIL PROTECTED] Sänt av: [EMAIL PROTECTED] 2006-01-24 01:06 Sänd svar till [EMAIL PROTECTED] Till mapInfo-L@lists.directionsmag.com Kopia Ärende RE: [MI-L] Number of fields On 23 Jan 2006 at 22:27, Peter Horsbøll Møller [EMAIL PROTECTED] wrote: As far as I remember there is a limit of 4000 bytes per record Ah, thank you Sir - you've probably just solved a long-standing problem I've had. I have a Microsoft Access table with only 56 fields that I call from MapInfo, but found that I got strange errors when adding a new field. I can't remember the actual error message, but it wasn't anything logical to me, and took ages to figure out that it was caused by this extra field being added. So, I went without the field, knowing that I hadn't reached the 255 field limit, but must have bumped into some other limitation. Dave ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l -- bob young ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
Re: [MI-L] Number of fields
Hi Bob, You are right - it is clearly wrong what I have written. Always read the whole sentence before clicking send, especially after having changed something in the middle :-) I expect you to update the wiki with some details on your wonderful 64-bit TAB format? Regards Uffe - Original Message - From: bob young [EMAIL PROTECTED] To: Uffe Kousgaard [EMAIL PROTECTED] Sent: Tuesday, January 24, 2006 12:50 PM Subject: Re: [MI-L] Number of fields Hi Uffe I think your answer might be a bit unclear to some. I think you mean: MapInfo even on NTFS has 2 GB limit - therefore the limit is with MapInfo. It might suggest to some that Windows itself with NTFS has a 2 GB limit. I have created and used files up to 4 GB incidentally on FAT 32. You need to use a 4 byte unsigned pointer, whereas MapInfo use a 4 byte signed, therefore only getting half the range. Hope you are well. Regards Bob In message [EMAIL PROTECTED], Uffe Kousgaard [EMAIL PROTECTED] writes From: Mats Elfström [EMAIL PROTECTED] I think your analysis is correct. I believe the numbers are as follows: Max Tab file size: 2 GB (OS limit, not MapInfo) It is a MapInfo limit, since even Windows with NTFS filesystem has the 2 GB limit. I tried to enter it into the Wiki: http://www.mapinfo-l.com/Wiki/TABFormat Regards Uffe ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l -- bob young ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
RE: [MI-L] Number of fields
There may be an actual field number limit but I've found in my experience that the real limiting factor is more of how long the combined field names length is. That is what I have found to be my limiting factor Example: sCombinedFieldCharacterlength = LongFieldname1 + Longfieldname2 + Longfieldname3 + LongfieldnameN. Once you add up the combined character length of these fields, and if you keep adding long field named fields, you will hit a limit to where you can no longer create the table. I cant remember what the actual character length is but I'll look back into my notes and let you know. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Middleton Sent: Sunday, January 22, 2006 7:48 PM To: mapinfo-l@lists.directionsmag.com Subject: [MI-L] Number of fields Hi all, What is the limitations on the number of fields you can have in any one layer/table, if so what are they and does the version of MI make any difference. Regards Paul Middleton GIS Manager Eurobodalla Shire Council PO Box 99, Moruya NSW, 2537 Australia URL: http://www.esc.nsw.gov.au http://www.esc.nsw.gov.au Phone (02) 44741270 Fax (02) 44741234 ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l __ This e-mail has been scanned by MCI/MessageLabs Managed Email Service. ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
RE: [MI-L] Number of fields
As far as I remember there is a limit of 4000 bytes per record Peter Horsbøll Møller GIS Developer, MTM Geographical Information IT COWI A/S Odensevej 95 DK-5260 Odense S. Denmark Tel +45 6311 4900 Direct +45 6311 4908 Mob +45 5156 1045 Fax +45 6311 4949 E-mail [EMAIL PROTECTED] http://www.cowi.dk/gis -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Nabors, Steve Sent: Monday, January 23, 2006 3:13 PM To: Paul Middleton Cc: mapinfo-l@lists.directionsmag.com Subject: RE: [MI-L] Number of fields There may be an actual field number limit but I've found in my experience that the real limiting factor is more of how long the combined field names length is. That is what I have found to be my limiting factor Example: sCombinedFieldCharacterlength = LongFieldname1 + Longfieldname2 + Longfieldname3 + LongfieldnameN. Once you add up the combined character length of these fields, and if you keep adding long field named fields, you will hit a limit to where you can no longer create the table. I cant remember what the actual character length is but I'll look back into my notes and let you know. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Middleton Sent: Sunday, January 22, 2006 7:48 PM To: mapinfo-l@lists.directionsmag.com Subject: [MI-L] Number of fields Hi all, What is the limitations on the number of fields you can have in any one layer/table, if so what are they and does the version of MI make any difference. Regards Paul Middleton GIS Manager Eurobodalla Shire Council PO Box 99, Moruya NSW, 2537 Australia URL: http://www.esc.nsw.gov.au http://www.esc.nsw.gov.au Phone (02) 44741270 Fax (02) 44741234 ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l __ This e-mail has been scanned by MCI/MessageLabs Managed Email Service. ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
Re: [MI-L] Number of fields
Paul Middleton writes: What is the limitations on the number of fields you can have in any one layer/table, if so what are they and does the version of MI make any difference. In an old MapInfo Users guide, the Frequently Asked Questions section in the Appendix says it's 255. But IMHO, if you ever get up to needing that many fields in your table, you probably ought to re-examine your data structure and ask your self if it's as normalized (from a DBMS point of view) as it should be. ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
RE: [MI-L] Number of fields
On 23 Jan 2006 at 22:27, Peter Horsbøll Møller [EMAIL PROTECTED] wrote: As far as I remember there is a limit of 4000 bytes per record Ah, thank you Sir - you've probably just solved a long-standing problem I've had. I have a Microsoft Access table with only 56 fields that I call from MapInfo, but found that I got strange errors when adding a new field. I can't remember the actual error message, but it wasn't anything logical to me, and took ages to figure out that it was caused by this extra field being added. So, I went without the field, knowing that I hadn't reached the 255 field limit, but must have bumped into some other limitation. Dave ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
Ang. RE: [MI-L] Number of fields
Hi Dave! I think your analysis is correct. I believe the numbers are as follows: Max field length: 255 bytes Max number of fields: 255 (as someone pointed out, if you need that many, it's bad database design) Max length of record: ~4000 bytes (quickly reached if you join in some Access tables) Max Tab file size: 2 GB (OS limit, not MapInfo) I have noted on some occasions that some data tables have very long character fields, 255 bytes. I believe this data to be of Access origin, and originally were memo fields which have no limit length in Access. As the DB structure of MI cannot handle memo fields they probably get the max character field length when put into the MI DB format. Imagine what will happen if you have a number of such fields, the 4000 byte barrier is reached very quickly. Hälsning / Best regards Mats.E FB Engineering AB Södra Förstadsgatan 26 211 43 Malmö Tel: 040-660 25 50 Mobil: 0705-27 60 27 Fax: 040-660 25 99 [EMAIL PROTECTED] www.fbe.se David Baker [EMAIL PROTECTED] Sänt av: [EMAIL PROTECTED] 2006-01-24 01:06 Sänd svar till [EMAIL PROTECTED] Till mapInfo-L@lists.directionsmag.com Kopia Ärende RE: [MI-L] Number of fields On 23 Jan 2006 at 22:27, Peter Horsbøll Møller [EMAIL PROTECTED] wrote: As far as I remember there is a limit of 4000 bytes per record Ah, thank you Sir - you've probably just solved a long-standing problem I've had. I have a Microsoft Access table with only 56 fields that I call from MapInfo, but found that I got strange errors when adding a new field. I can't remember the actual error message, but it wasn't anything logical to me, and took ages to figure out that it was caused by this extra field being added. So, I went without the field, knowing that I hadn't reached the 255 field limit, but must have bumped into some other limitation. Dave ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l ___ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
