Problem with MATERIALIZED VIEW (snapshot)

Question

Hi,
I've any problem with creating MATERIALIZED VIEW (snapshot)
My table is ROOMS:
SQL> DESC ROOMS
Name Null? Type
LS_ID VARCHAR2(32)
BL_ID NOT NULL VARCHAR2(32) PRIMARY KEY1
FL_ID NOT NULL VARCHAR2(4) PRIMARY KEY2
RM_ID NOT NULL VARCHAR2(8) PRIMARY KEY3
SITE_ID VARCHAR2(32)
SQL> SELECT COUNT(*)
2 FROM ROOMS;
COUNT(*)
203973
SQL> SELECT COUNT (TOT)
2 FROM (SELECT COUNT(*) TOT, LS_ID, SITE_ID
3 FROM ROOMS
4 GROUP BY LS_ID, SITE_ID);
COUNT(TOT)
11673
I'd like to create one MATERIALIZED VIEW that refresh every 30 seconds when I insert, update or delete on ROOMS table.
I tried this:
CREATE MATERIALIZED VIEW ROOMS_SNAP
BUILD IMMEDIATE
REFRESH complete
START WITH to_date(sysdate,'dd/mm/yyyy hh24:mi:ss')
NEXT sysdate + 30/86400
disable QUERY REWRITE
AS
SELECT LS_ID, SITE_ID
FROM ROOMS
GROUP BY LS_ID, SITE_ID
but when I insert, update or delete one record on ROOMS table, ROOMS_SNAP not refresh.
What I wrong?
How Can I write MATERIALIZED VIEW to maintain synchronization
between ROOMS_SNAP AND LS_ID, SITE_ID by ROOMS?
Thanks

Answer 1

Try this way:
SQL> SHOW PARAMETER JOB
NAME                                 TYPE        VALUE
job_queue_processes                  integer     0
SQL> ALTER SYSTEM SET JOB_QUEUE_PROCESSES=20 SCOPE=MEMORY;
SQL> create materialized view log on emp tablespace jam_ts
  2  with rowid, primary key;
Materialized view log created.
SQL> create materialized view emp_mat
  2  tablespace jam_ts
  3  refresh fast start with sysdate
  4  next sysdate + interval '15' second as
  5  select * from emp where deptno=30;
Materialized view created.
SQL> update  emp
  2  set     ename=lower(ename)
  3  where   deptno=30;
6 rows updated.
SQL> commit;
Commit complete.
---"After 15 seconds it will be refreshed automatically...."
SQL> select * from emp_mat;
  EMPNO ENAME      JOB           MGR HIREDATE      SAL    COMM  DEPTNO
   7499 allen      SALESMAN     7698 20-FEB-81    1600     300      30
   7521 ward       SALESMAN     7698 22-FEB-81    1250     500      30
   7654 martin     SALESMAN     7698 28-SEP-81    1250    1400      30
   7698 blake      MANAGER      7839 01-MAY-81    2850              30
   7844 turner     SALESMAN     7698 08-SEP-81    1500       0      30
   7900 james      CLERK        7698 03-DEC-81     950              30
6 rows selected.Message was edited by:
Jameel