(PHP 5, PECL OCI8 >= 1.1.0)
OCI-Lob::seek — Sets the internal pointer of the large object
$offset
   [, int $whence = OCI_SEEK_SET
  ] )Sets the internal pointer of the large object.
offset
       Indicates the amount of bytes, on which internal pointer should be
       moved from the position, pointed by whence.
      
whenceMay be one of:
OCI_SEEK_SET - sets the position equal to 
         offset
        OCI_SEEK_CUR - adds offset 
         bytes to the current position  
        OCI_SEEK_END - adds offset
         bytes to the end of large object (use negative value to move to a position
         before the end of large object)
        
   Returns TRUE on success or FALSE on failure.