Re: [Dspace-tech] [Dspace-general] DSpace Bistream
On Wed, Jul 04, 2007 at 01:13:38PM +0200, Ina Smith wrote: My question relates to the preservation of the bitstream URL: In stead of linking from another database (e.g. our library catalogue) to the Item URL, we would like to link directly to the Bitstream URL. Is there any guarantee that the Bitstream URL will also stay persistent if we decide to export our items to another server one day? We also use the CNRI Handle System. The short answer is no. Bitstreams don't get handles, so if you move your DSpace having directly referenced a Bitstream URL, that link will either break, or you will have to maintain it yourself (which is a bad road to go down). Until this is fixed (and I should point out that not everyone thinks it's a problem) you shouldn't use Bitstream URLs anywhere unless you're prepared to deal with it when the time comes. cheers, Jim -- James Rutherford | Hewlett-Packard Limited registered Office: Research Engineer | Cain Road, HP Labs | Bracknell, Bristol, UK | Berks +44 117 312 7066 | RG12 1HN. [EMAIL PROTECTED] | Registered No: 690597 England The contents of this message and any attachments to it are confidential and may be legally privileged. If you have received this message in error, you should delete it from your system immediately and advise the sender. To any recipient of this message within HP, unless otherwise stated you should consider this message and attachments as HP CONFIDENTIAL. - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ DSpace-tech mailing list DSpace-tech@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dspace-tech
Re: [Dspace-tech] [Dspace-general] DSpace Bistream
On 05/07/07, James Rutherford [EMAIL PROTECTED] wrote: On Wed, Jul 04, 2007 at 01:13:38PM +0200, Ina Smith wrote: My question relates to the preservation of the bitstream URL: In stead of linking from another database (e.g. our library catalogue) to the Item URL, we would like to link directly to the Bitstream URL. Is there any guarantee that the Bitstream URL will also stay persistent if we decide to export our items to another server one day? We also use the CNRI Handle System. The short answer is no. Bitstreams don't get handles, so if you move your DSpace having directly referenced a Bitstream URL, that link will either break, or you will have to maintain it yourself (which is a bad road to go down). Until this is fixed (and I should point out that not everyone thinks it's a problem) you shouldn't use Bitstream URLs anywhere unless you're prepared to deal with it when the time comes. Software systems do not persist or guarantee URLs or identifiers, people do. This use case is precisely the one that led to DSpace bitstream URLs being in the current form they are -- a form that is easy to persist, but does not require the overhead of minting and resolving huge numbers of Handles. So it depends what you mean by 'export ... to another server'. If you're just thinking about having DSpace run on beefier hardware, although the 'preferred' bitstream direct access URL may change in the future, certainly the existing /bitstream/* URLs will always be supported by DSpace as redirects, so provided the new server can get the same DNS name you will be able to persist the bitstream URLs. If you're thinking about running other software, provided you still have control of the DNS space, it shouldn't be too hard to keep (e.g.) dspace.up.ac.za/bitstream/123/456/1/foo.pdf pointing at the right place. At least, it wouldn't be any harder to do this than to update a huge number of Handle records to point at the right (new) place. If you think that the DNS name may change, you would have to look into Handles or another ID scheme resilient to DNS name changes of the actual server. Rob - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ DSpace-tech mailing list DSpace-tech@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dspace-tech
Re: [Dspace-tech] [Dspace-general] DSpace Bistream
On Thu, 2007-07-05 at 16:03 +0100, James Rutherford wrote: On Wed, Jul 04, 2007 at 01:13:38PM +0200, Ina Smith wrote: My question relates to the preservation of the bitstream URL: In stead of linking from another database (e.g. our library catalogue) to the Item URL, we would like to link directly to the Bitstream URL. Is there any guarantee that the Bitstream URL will also stay persistent if we decide to export our items to another server one day? We also use the CNRI Handle System. Actually, that poses an interesting question on the future of the handle system - it's not unreasonable to have urls / references that are *relative* to the resolution of a handle, so could there in the future be a way of passing additional information through to the URL resolved by the handle system resolver? (There is also another interesting theoretical question about the issues of only exporting *some* of the items identified under a given prefix, but I'll avoid that now). The short answer is no. Bitstreams don't get handles, so if you move your DSpace having directly referenced a Bitstream URL, that link will either break, or you will have to maintain it yourself (which is a bad road to go down). Until this is fixed (and I should point out that not everyone thinks it's a problem) you shouldn't use Bitstream URLs anywhere unless you're prepared to deal with it when the time comes. In general, I would agree that it isn't a problem if Bitstreams don't routinely get handles / persistent / external identifiers. As long as there are consistent internal identifiers, and a way of mapping a persistent / external identifier through metadata, then (in theory) you only need to choose to assign an identifier to the Bitstream's metadata, and you can guarantee it's persistence. Happily enough Jim, you've already been doing that ;) G This email has been scanned by Postini. For more information please visit http://www.postini.com - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ DSpace-tech mailing list DSpace-tech@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dspace-tech
