Altering Materialized view.

Question

I have a materialized view with 2 columns,
Now I want to add two more columns to that MVIEW.
Is there any way to add those two columns without droping the
existed materialized view.
CREATE MATERIALIZED VIEW MDT.MASTER_MV
BUILD IMMEDIATE
REFRESH COMPLETE ON DEMAND
WITH PRIMARY KEY
AS
SELECT empno,ename
FROM emp;
Now I want to add sal and comm columns to the
mview MASTER_MV.Without droping it.
Please help me.

Answer 1

>
Now I want to add sal and comm columns to the
mview MASTER_MV.Without droping it.
>
The technically correct answer? Just use an ALTER statement to add the columns
This works on 11g r2.
CREATE MATERIALIZED VIEW MASTER_MV
BUILD IMMEDIATE
REFRESH COMPLETE ON DEMAND
WITH PRIMARY KEY
AS
SELECT empno,ename
FROM emp
alter materialized view master_mv add (sal number(7,2), comm number(7,2))This adds the columns and you can refresh the MV and select the new columns.
The columns won't have any data and you won't be able to put data in them.
But hey - you didn't say anything about that.
Practically speaking you will have to drop and recreate the MV with the additional columns.
Here is an interesting link about using a prebuilt table for the MV which makes a drop and recreate go quickly
http://www.rampant-books.com/art_nanda_fast_regfresh_materialized_views.htm