UPDATING the query in materialized view

Question

Hi,
i have a little doubt in Materialized view. i created a materialized view and log with the following query,
create table test_mv (a number ,b number )
alter table test_mv add constraint t_pk primary key ( a );
insert into test_mv values (1,2);
insert into test_mv values(2,2);
insert into test_mv values(3,2);
insert into test_mv values(4,2);
insert into test_mv values(5,2);
commit;
CREATE MATERIALIZED VIEW LOG ON test_mv
WITH SEQUENCE, ROWID
*(a,b)*
INCLUDING NEW VALUES;
CREATE MATERIALIZED VIEW product_sales_mv
ENABLE QUERY REWRITE
AS SELECT  b  from test_mv;
Now i want to update the query in the MV as 'Select a from test_mv' . for that i tried with
*'ALTER MATERIALIZED VIEW product_sales_mv AS SELECT a from test_mv;'*
But it throwing error,
Error starting at line 5 in command:
alter  MATERIALIZED VIEW product_sales_mv   AS SELECT  b  from test_mv
Error report:
SQL Error: ORA-00933: SQL command not properly ended
+00933. 00000 - "SQL command not properly ended"+
*Cause:+   
*Action:+
i guess i am doing wrong. kindly help me here. i want to update it without drop and recreate.
thanks,
Jeevanand.Ke

Answer 1

Hi Jeeva,
No. you cannot add or drop columns to the materialized view using the ALTER Statement.
To Change the Structure of the view , drop and re-create the materialized view.
To Alter a materialized view log, You can use the ALTER MATERIALIZED VIEW LOG. By this,
You can add new columns to a materialized view log.
ALTER MATERIALIZED VIEW LOG ON sggi_mrps.emp ADD(deptno);Thanks,
Shankar
Edited by: Shankar Viji on Aug 24, 2012 2:11 AM