Index On Materialized View

Question

I have created a materialized view that involves joining 4 tables for diferent where conditions. How can I create index on this materialized view.
Thanks

Answer 1

Yes, but it is done automatically:
SQL> create materialized view emp_dept_mv
  2  as
  3  select e.empno
  4       , e.ename
  5       , e.sal
  6       , d.deptno
  7       , d.dname
  8    from emp e
  9       , dept d
10   where e.deptno (+) = d.deptno
11  /
Gematerialiseerde view is aangemaakt.
SQL> create index i1 on emp_dept_mv (deptno)
  2  /
Index is aangemaakt.
SQL> exec dbms_stats.gather_table_stats(user,'emp_dept_mv',cascade=>true)
PL/SQL-procedure is geslaagd.
SQL> set autotrace on explain
SQL> select * from emp_dept_mv where deptno = 40
  2  /
     EMPNO ENAME             SAL     DEPTNO DNAME
                                         40 OPERATIONS
1 rij is geselecteerd.
Uitvoeringspan
   0      SELECT STATEMENT Optimizer=CHOOSE (Cost=2 Card=4 Bytes=96)
   1    0   TABLE ACCESS (BY INDEX ROWID) OF 'EMP_DEPT_MV' (Cost=2 Card=4 Bytes=96)
   2    1     INDEX (RANGE SCAN) OF 'I1' (NON-UNIQUE) (Cost=2 Card=4)
SQL> set autotrace off
SQL> insert into dept (deptno, dname) values (50, 'EXTRA DEPT')
  2  /
1 rij is aangemaakt.
SQL> exec dbms_mview.refresh('emp_dept_mv')
PL/SQL-procedure is geslaagd.
SQL> set autotrace on explain
SQL> select * from emp_dept_mv where deptno = 50
  2  /
     EMPNO ENAME             SAL     DEPTNO DNAME
                                         50 EXTRA DEPT
1 rij is geselecteerd.
Uitvoeringspan
   0      SELECT STATEMENT Optimizer=CHOOSE (Cost=2 Card=4 Bytes=96)
   1    0   TABLE ACCESS (BY INDEX ROWID) OF 'EMP_DEPT_MV' (Cost=2 Card=4 Bytes=96)
   2    1     INDEX (RANGE SCAN) OF 'I1' (NON-UNIQUE) (Cost=2 Card=4)Regards,
Rob.