
130 5.4 Dimension Objects and Performance
Unfortunately in Figure 5.14 it is shown that the optimizer does not
need an Oracle Dimension object to figure out the obvious. Now let’s create
the appropriate dimension against the materialized view join:
DROP DIMENSION dm_time;
CREATE DIMENSION dm_time
LEVEL month IS (time.month#)
LEVEL quarter IS (time.quarter#)
LEVEL year IS (time.year#)
HIERARCHY time_rollup(month CHILD OF quarter CHILD OF year)
ATTRIBUTE month DETERMINES(time.monabbrev, time.monthname);
Note: The ALTER DIMENSION statement could have been used here.
By connecting the TIME dimension between year, quarter, and month,
as shown in the above CREA ...