I have a case where user NEIL has SELECT privs on CUBS_OWNER.state_codes. NEIL also has resource and create session



SQL> show user
USER is "NEIL"

SQL> select * from user_sys_privs;

USERNAME PRIVILEGE ADM
---------- ------------------------------ ---
NEIL CREATE SESSION NO
NEIL UNLIMITED TABLESPACE NO

SQL> select * from user_role_privs;

USERNAME GRANTED_ROLE ADM DEF OS_
---------- ------------------------------ --- --- ---
NEIL CONNECT NO YES NO
NEIL RESOURCE NO YES NO

SQL> select * from all_tab_privs where table_name='STATE_CODES' and table_schema='CUBS_OWNER';

GRANTOR GRANTEE TABLE_SCHEMA TABLE_NAME PRIVILEGE GRA HIE
--------------- ---------- --------------- --------------- ---------- --- ---
CUBS_OWNER NEIL CUBS_OWNER STATE_CODES SELECT NO NO

SQL> update cubs_owner.state_codes set name=name;
update cubs_owner.state_codes set name=name
*
ERROR at line 1:
ORA-01031: insufficient privileges

However, as NEIL, I can do a SELECT * FROM cubs_owner.state_codes FOR UPDATE;

SQL> select * from cubs_owner.state_codes for update;

ST NAME CNT CREATED_D MODIFIED_ WG_ALLOW_IND ST CREATED_BY
-- -------------------- --- --------- --------- ------------ -- ----------
MODIFIED_BY BEG_DT END_DT
----------- --------- ---------
AK Alaska 31-MAR-00 1 02 10
01-APR-90

AL Alabama 31-MAR-00 1 01 10
01-APR-90
<SNIP>
63 rows selected.


Now, in another session, as cubs_owner, I try to alter table state_codes and get the error that the table is locked

SQL> show user
USER is "CUBS_OWNER"

SQL> alter table state_codes add (dummyfield varchar2(256));
alter table state_codes add (dummyfield varchar2(256))
*
ERROR at line 1:
ORA-00054: resource busy and acquire with NOWAIT specified


So, my question is, how can a user with SELECT only privileges lock the table and prevent the schema owner from making changes?