pg_lo_unlink() deletes a large object with the oid. 성공일 경우 TRUE를, 실패일 경우 FALSE를 반환합니다.
To use the large object (lo) interface, it is necessary to enclose it within a transaction block.
참고: This function used to be called pg_lo_unlink().
See also pg_lo_create() and pg_lo_import().