To use PostgreSQL large objects from PHP3, you must
include your code in a transaction. This not explained
in the PHP documentation (ok, this a PostgreSQL related
problem but it still would be nice to add a short
description of this issue in the PHP documentation). Here
is a valid PHP code to create a large object in a
PostgreSQL database:

<?
  $database = pg_Connect ("", "", "", "", "jacarta");
  pg_exec ($database, "begin");
  $oid = pg_locreate ($database);
  echo ("$oid\n");
  $handle = pg_loopen ($database, $oid, "w");
  echo ("$handle\n");
  pg_lowrite ($handle, "gaga");
  pg_loclose ($handle);
  pg_exec ($database, "commit");
?>