Skip site navigation (1) Skip section navigation (2)

Re: pqlib large object error

From: Edward Amsden <amsden_linux(at)embarqmail(dot)com>
To: pgsql-interfaces(at)postgresql(dot)org
Subject: Re: pqlib large object error
Date: 2008-06-10 21:46:41
Message-ID: 1213134401.17568.0.camel@dad-desktop2 (view raw, whole thread or download thread mbox)
Lists: pgsql-interfaces
On Tue, 2008-06-10 at 16:49 -0400, Tom Lane wrote:
> Edward Amsden <amsden_linux(at)embarqmail(dot)com> writes:
> > On Tue, 2008-06-10 at 14:29 -0400, Tom Lane wrote:
> >> Edward Amsden <amsden_linux(at)embarqmail(dot)com> writes:
> >>> I cannot seem to figure this error message out:
> >>> 
> >>> ERROR:  duplicate key value violates unique constraint "pg_largeobject_loid_pn_index"
> >> 
> >> Huh, that shouldn't happen.  Is it repeatable?
> > Yes. It happens every time the program runs, no matter what db or user,
> > tried unix socket and tcp connect
> >> What PG version
> >> is your server?
> > 8.3.1, running on Ubuntu Linux
> Hmph.  The only thing I can think of is that that index is corrupt,
> but it seems unlikely that it would be so in all databases.  What
> happens if you REINDEX pg_largeobject?
The error has disappeared. Now it can't write to the object. lo_open
seems to be successful, but lo_write is failing with:
> ERROR:  invalid large-object descriptor: 0
0 is a valid value (I checked) but it appears it cannot write to the object. lo_open should return a negative value if it cannot create the handle

Here is my code:

if (PQstatus(connect1) == CONNECTION_OK) {
		lo_1 =  lo_creat(connect1, INV_READ|INV_WRITE);
		if (lo_1 > 0) {
			lo_1_fd = lo_open(connect1, lo_1, INV_READ|INV_WRITE);
			written = lo_write(connect1, lo_1_fd, filedata, (size_t) filelen);
			if (written == filelen) {
				printf ("Write successful, %d bytes written.\n", written);
			} else if (written < 0) {
				printf ("Write unsuccessful: %s\n", PQerrorMessage(connect1));
			} else {
				printf ("Write partially successful. %d of %d bytes written.\n",
written, filelen);
		} else {
			fprintf (stderr, "Unable to create large object: %s\n",
	} else {
		fprintf (stderr, "Unable to open connection: %s\n",

Let me know if it's unreadable, my mail client can do funny things with

> 			regards, tom lane

In response to

pgsql-interfaces by date

Next:From: Tom LaneDate: 2008-06-10 23:05:25
Subject: Re: pqlib large object error
Previous:From: Tom LaneDate: 2008-06-10 21:21:56
Subject: Re: pqlib large object error

Privacy Policy | About PostgreSQL
Copyright © 1996-2017 The PostgreSQL Global Development Group