Disallow select for update

Question

Hi,
I am making a read only user, with select rights on all of the tables in another scheme. How do I dissalow this user to lock the production table with select for update?
Regards
Nico

Answer 1

Good idea in principle, but there may be more efficient solutions than DISTINCT. Any operation which prevents view merging appears to work (or rather not work) e.g.
CREATE OR REPLACE VIEW view_name
AS
   SELECT /*+ NO_MERGE */ column_name
   FROM   table_name;...is sufficient to raise ORA-02014: cannot select FOR UPDATE from view with DISTINCT, GROUP BY, etc. when attempting SELECT ... FOR UPDATE.
It is important to note though that /*+ NO_MERGE */ could theoretically be ignored by the optimizer - another cheap alternative you might consider would be to reference ROWNUM in the view definition, e.g.
CREATE OR REPLACE VIEW view_name
AS
   SELECT column_name
   FROM   table_name
   WHERE  ROWNUM >= 1;