Which privileges I can give for a user who can only do DML and queries of his schema. The answer is only create session and quota on a tablespace. Let's see how we can do it. 1)Create a new user named least_priv and make his password l. Code (Text): SQL> grant create session to least_priv identified by l; Grant succeeded. 2)Grant some quota suppose 1M on tablespace users to user least_priv. Code (Text): SQL> alter user least_priv quota 1M on users; User altered. 3)Create some objects in least_priv's schema. Code (Text): SQL> create table least_priv.test(a number, b number); Table created. 4)Now connect as least_priv user and do operation on his table. He can do every work with the table in his schema, even he can drop it. Code (Text): SQL> conn least_priv/l Connected. SQL> insert into test values(1,2); 1 row created. SQL> delete from test; 1 row deleted. SQL> alter table test add c varchar2(10); Table altered. SQL> drop table test; Table dropped.