Role to access the table only but not data from Table in Oracle Exadata - sql

Question

Users have create table statement with select statement from multiple tables from multiple schema. I want to restrict them to read data and allow them to create empty table in their schema with metadata only not data. This I want to do at user access and roles level.
Please tell me how I can do this?
I have tried giving them read access on underlying tables but users can see data as well.
Create table cust_acct_details
as
select *
from ep_rel.acct a
inner join ep_dnf.Cust_account ca
on a.acct_id = ca.acct_id
Tables should create without data.

Answer 1

Add below condition to your code
-- condition to add where 1<>1
Create table cust_acct_details
as
select *
from ep_rel.acct a
inner join ep_dnf.Cust_account ca
on a.acct_id = ca.acct_id
where 1<>1
Please make sure there are unique column names in your select statement. Oracle will not allow same column name in one table. Please use alias instead of *.

Answer 2

If you remove all tablespace privileges from a user they can still create tables but they won't be able to populate them.
For example, if you run this PL/SQL block to revoke all tablespace quotas from one user:
begin
for users in
(
select 'alter user '||username||' quota 0 on '||tablespace_name v_sql
from dba_ts_quotas
where username = 'TEST_USER'
order by 1
) loop
execute immediate users.v_sql;
end loop;
end;
/
Now the user can create tables but will get an error if they try to add rows:
SQL> create table test1(a number);
Table created.
SQL> insert into test1 values(1);
insert into test1 values(1)
*
ERROR at line 1:
ORA-01536: space quota exceeded for tablespace 'USERS'
For metadata, users can always see the metadata in their own schema. To allow them to view the metadata in other schema, run a grant like:
grant select_catalog_role to the_user;
Then that user can view the metadata either in the ALL_ data dictionary views, or using DBMS_METADATA.GET_DDL.