(PHP 4 >= 4.2.0, PHP 5)
pg_lo_unlink — Delete a large object
$connection
   , int $oid
   )
   pg_lo_unlink() deletes a large object with the
   oid. Returns TRUE on success or FALSE on failure.
  
To use the large object interface, it is necessary to enclose it within a transaction block.
Note:
This function used to be called pg_lounlink().
connection
       PostgreSQL database connection resource.  When 
       connection is not present, the default connection 
       is used. The default connection is the last connection made by 
       pg_connect() or pg_pconnect().
      
oidThe OID of the large object in the database.
   Returns TRUE on success or FALSE on failure.
  
Example #1 pg_lo_unlink() example
<?php
   // OID of the large object to delete
   $doc_oid = 189762345;
   $database = pg_connect("dbname=jacarta");
   pg_query($database, "begin");
   pg_lo_unlink($database, $doc_oid);
   pg_query($database, "commit");
?>