"Greg Sabino Mullane" <greg@turnstep.com> writes:
> I'm having some problems with lo_open inside of DBD::Pg (which
> uses libpq) and need help in debugging the problem.
lo_open doesn't work unless inside a transaction block (and even
if it did work, the result would be useless to you).
I believe the reason for the -1 result is this code inside libpq's
lo_open:
/* have to do this to reset offset in shared fd cache */ /* but only if fd is valid */ if (fd >= 0
&&lo_lseek(conn, fd, 0L, SEEK_SET) < 0) return -1;
Since you forgot to start a transaction block, the results of the
backend lo_open call are already dead and the lo_lseek fails withERROR: invalid large-object descriptor: 0
This looks rather considerably like a hack to compensate for a very
long-gone bug ... can anyone see a reason not to take it out?
Of course taking it out wouldn't improve Greg's results much, since
he'd still get a failure at the next LO operation, but this sure
looks like it's incurring a useless network round trip...
regards, tom lane
