Big Problem with Instead Of Trigger

Question

I have following problem: I created my own user-table where I want to store some
attributes like user-foto etc... This table I join with the HTMLDB
wwv_flow_fnd_user (I gave myself the select grant on it) in a view
On the view I created an INSTEAD-OF-Trigger for DELETE-Operations where I delete
only my user-table. But when I execute it it gives me an
ORA-01031: insufficient privileges
I can not understand it.
<pre>
===========================================================
SQL*Plus: Release 10.2.0.1.0 - Production on Tue Sep 27 05:28:13 2005
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
SQL> DROP TABLE my_users
2 ;
Table dropped.
SQL> CREATE TABLE my_users AS
2 SELECT user_id
3 FROM flows_020000.wwv_flow_fnd_user
4 ;
Table created.
SQL> ALTER TABLE my_users ADD my_attr VARCHAR2(10);
Table altered.
SQL> ALTER TABLE my_users ADD CONSTRAINT pk_my_users PRIMARY KEY( user_id );
Table altered.
SQL> CREATE OR REPLACE VIEW v_my_users
2 AS
3 SELECT u2.user_id,
4 u.user_name,
5 u.first_name,
6 u.last_name,
7 u2.my_attr
8 FROM flows_020000.wwv_flow_fnd_user u,
9 my_users u2
10 WHERE u2.user_id = u.user_id
11 ;
View created.
SQL> CREATE OR REPLACE TRIGGER trg_del_v_my_users
2 INSTEAD OF DELETE ON v_my_users
3 FOR EACH ROW
4 BEGIN
5 DELETE my_users
6 WHERE user_id = :OLD.user_id
7 ;
8 END;
9 /
Trigger created.
SQL> DELETE v_my_users WHERE 1=2
2 ;
DELETE v_my_users WHERE 1=2
ERROR at line 1:
ORA-01031: insufficient privileges
===========================================================
</pre>
And: If there is no PK on table my_users I got not error!
Can anybody explain it?
And: How can I include my listings in the forum with courier font?

Answer 1

Is the primary key in this table referencing any table(s) in other schema? How should this work?
Look at the script above:
ALTER TABLE my_users ADD CONSTRAINT pk_my_users PRIMARY KEY( user_id );
Bye,
Rumburak