Can we optimize the query : It is taking a lot of time

Question

the following query is taking a lot of time ...
Can anyone suggest to make it run faster ???
table B has 12 million records
table a has 10000 records
CREATE TABLE less_time
     PARALLEL
     NOLOGGING
     AS
     SELECT a.user_id,a.mp_id, COUNT(product_id) product _count
     FROM table a,table b
     WHERE TRUNC(a.call_time) < TRUNC(SYSDATE) - 1
     AND a.history_id = b.call_id
     AND b.product_type = 1
     AND b..product_status= 50
     AND user_id IS NOT NULL
     GROUP BY user_id,mp_id;

Answer 1

analyze index indx_mtx compute statistics
thanks for explaining David ...
Actually I somewhat bettered it
i made a consolidated index on table b
like create index indx_ty on table b (call_id,mp_id,user_id,b.product_type,product_status)
now the explain plan shows that the query is much much faster also i did one trick in the query
SELECT a.user_id,a.mp_id, COUNT(product_id) product _count
i changed to SELECT a.user_id,a.mp_id, COUNT(1) product _count
to enable it to do FFS
thanks anyways ....