Обсуждение: Large object - what's happening?
Hi, I decided how to deal with my large objects, and now I'm trying to get them going in a python script. I'm using pygresql. Is this considered a good thing? Should I use something else? The syntax looks so simple - just loimport(filename) I get a python error: _pg.err: can't create large object In the postmaster log is a one-liner: ERROR: lo_lseek: invalid large obj descriptor (0) Maybe I'm calling it wrong. Maybe I need to upgrade from 7.2.1 to 7.3.x? Maybe I need a new book - Practical Postgresql is very light on discussion of large objects, and is based on 7.1 or so. Any clues? Pointers to documents? thanks Cath Cath Lawrence, Cath.Lawrence@anu.edu.au Senior Scientific Programmer, Centre for Bioinformation Science, John Curtin School of Medical Research (room 4088) Australian National University, Canberra ACT 0200 ph: (02) 61257959 mobile: 0421-902694 fax: (02) 61252595
Cath > I get a python error: > _pg.err: can't create large object > > In the postmaster log is a one-liner: > ERROR: lo_lseek: invalid large obj descriptor (0) Make sure that you are doing the large object manipulation inside a transaction. I saw this type of error from the C interface when I forgot to wrap it in a transaction. It could also be caused by permissions. I think your database user needs some special priveleges to be able to create large objects. Warwick -- Warwick Hunter Agile TV Corporation Voice: +61 7 5584 5912 Fax: +61 7 5575 9550 mailto:whunter@agile.tv http://www.agile.tv
On Friday, August 15, 2003, at 09:19 AM, Warwick Hunter wrote: > Cath >> I get a python error: >> _pg.err: can't create large object >> In the postmaster log is a one-liner: >> ERROR: lo_lseek: invalid large obj descriptor (0) > Make sure that you are doing the large object manipulation > inside a transaction. I saw this type of error from the > C interface when I forgot to wrap it in a transaction. Thanks for the tip, but how do I do this? I have pygresql 3.3 and have gone through the readme thoroughly, and it says nothing about it. I assumed each call to the database must be a transaction. > It could also be caused by permissions. I think your > database user needs some special priveleges to be able > to create large objects. It's not this - when I am in command line psql mode I can use \lo_import, and it works fine. It's just my python script that fails. thanks C Cath Lawrence, Cath.Lawrence@anu.edu.au Senior Scientific Programmer, Centre for Bioinformation Science, John Curtin School of Medical Research (room 4088) Australian National University, Canberra ACT 0200 ph: (02) 61257959 mobile: 0421-902694 fax: (02) 61252595
> Thanks for the tip, but how do I do this? I am afraid I cannot help you with respect to Python. Warwick -- Warwick Hunter Agile TV Corporation Voice: +61 7 5584 5912 Fax: +61 7 5575 9550 mailto:whunter@agile.tv http://www.agile.tv