postgesql-7.3.3 lo_create/lo_open fails

[Colm Dobbs]

Hi Guys,

I'm currenlty involved in a port of our gateway code from a Solaris 8
environment to a HP-UX11.11 incorporating postgresql-7.3.3. We're having
some problems with creation and opening of large objects and was hoping
that you may be able to shed some light on them.

I extracted the LO code into the test program as below and am able to
recreate the problems:

int
main(
int argc,
char * argv[]
)
{
char chBytes[] = "FILLER";
int iLength = strlen(chBytes) ;

char * chTempDB = NULL;
chTempDB = getenv ("CMN_DBNAME ");
char *chTempUserName =NULL;
chTempUserName = getenv ("CMN_DBUSERNAM E");

PGconn * conn = PQsetdbLogin(NU LL, NULL, NULL, NULL, chTempDB,
chTempUserName, NULL);

/*
* check to see that the backend connection was successfully made
*/
if (PQstatus(conn) == CONNECTION_BAD)
{
cout << "Large object connection is bad " << endl;
}

PGresult * res = PQexec(conn, "begin");
PQclear(res);

Oid lobjId = lo_creat(conn, INV_READ|INV_WR ITE);
if (lobjId != -1)
{
cout << "Large object ID created :" << lobjId << endl;
int lobj_fd = lo_open(conn, lobjId, INV_WRITE);
cout << "Large object file descriptor :" << lobj_fd << endl;
if (lobj_fd != -1)
{
// write the large object
int nbytes_out = lo_write(conn, lobj_fd, chBytes, iLength);
cout << "Large object written - no of bytes :" << nbytes_out << endl;
(void) lo_close(conn, lobj_fd);
}
}

res = PQexec(conn, "end");
PQclear(res);
PQfinish(conn);
}

all worked fine on the Solaris box but on the HP the lo_creat returns 0
for the oid - subsequently lo_open returns -1 when an attempt is made to
open the object.

The configuration used to install postgresql-7.3.3 on the HP environment
is as follows:

configure CC=/bin/cc AR=/bin/ar CFLAGS=+DA2.0W --without-readline
--without-zlib

Has anyone come across this problem ? Any help on this would be much
appreciated

Thanks in advance

Colm

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[Tom Lane]

Colm Dobbs <Co********@aep ona.com> writes:

Oid lobjId = lo_creat(conn, INV_READ|INV_WR ITE);
if (lobjId != -1)

This coding is wrong --- lo_creat would return 0 (InvalidOid) on
failure, not -1. As for *why* it's failing, PQerrorMessage might
offer some hint. I'm a tad surprised by that myself; never heard
of it happening with a connection not already in an error state.

regards, tom lane

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