How to create Day and Hourly partitioning in Oracle 11g? - oracle

Question

I am using Oracle-11G database.
I am trying to create day wise partition and again sub-partition on hourly level.
Below is the script I am using
CREATE TABLE test_shipments
( order_date DATE NOT NULL
, delivery_date DATE NOT NULL
)
PARTITION BY RANGE (order_date)
INTERVAL (NUMTODSINTERVAL(1, 'day'))
SUBPARTITION BY RANGE (order_date)
( PARTITION p_2006_jul VALUES LESS THAN (TO_DATE('2006-08-01','YYYY-MM-DD'))
( SUBPARTITION p06_jul_e1 VALUES LESS THAN (TO_DATE('2006-08-01 12:00:00','YYYY-MM-DD hh24:mi:ss'))
,SUBPARTITION p06_jul_e2 VALUES LESS THAN (TO_DATE('2006-08-01 13:00:00','YYYY-MM-DD hh24:mi:ss'))
,SUBPARTITION p06_jul_e3 VALUES LESS THAN (TO_DATE('2006-08-01 14:00:00','YYYY-MM-DD hh24:mi:ss'))
)
);
I am expecting to have partition for every day and again sub-partition for every hour in that day. The above script creates partition per day only. Hourly sub-partition is not getting created. Can anyone please guide?

Answer 1

Why do you not create simple partition by Hourly range? Example: PARTITION BY RANGE (order_date) INTERVAL (INTERVAL '1' HOUR)
Anyway, this one works. However, you should use TIMESTAMP data type instead of DATE. For hour value you have to create a virtual column.
CREATE TABLE test_shipments (
order_date TIMESTAMP(0) NOT NULL,
order_date_hour NUMBER GENERATED ALWAYS AS (EXTRACT(HOUR FROM order_date)),
delivery_date DATE NOT NULL)
PARTITION BY RANGE (order_date)
INTERVAL (INTERVAL '1' DAY)
SUBPARTITION BY LIST (order_date_hour)
SUBPARTITION TEMPLATE
(SUBPARTITION HOUR00 VALUES (0),
SUBPARTITION HOUR01 VALUES (1),
SUBPARTITION HOUR02 VALUES (2),
SUBPARTITION HOUR03 VALUES (3),
...
SUBPARTITION HOUR22 VALUES (22),
SUBPARTITION HOUR23 VALUES (23)
)
(
PARTITION P_20150101 VALUES LESS THAN (TIMESTAMP'2015-01-01 00:00:00')
);
If you are enforced to use DATE data type you can do it like this:
CREATE TABLE test_shipments (
order_date DATE NOT NULL,
order_date_hour NUMBER GENERATED ALWAYS AS (TO_CHAR(order_date, 'HH24')),
delivery_date DATE NOT NULL)
PARTITION BY RANGE (order_date)
INTERVAL (INTERVAL '1' DAY)
SUBPARTITION BY LIST (order_date_hour)
SUBPARTITION TEMPLATE
(SUBPARTITION HOUR00 VALUES (0),
SUBPARTITION HOUR01 VALUES (1),
SUBPARTITION HOUR02 VALUES (2),
SUBPARTITION HOUR03 VALUES (3),
...
SUBPARTITION HOUR22 VALUES (22),
SUBPARTITION HOUR23 VALUES (23)
)
(
PARTITION P_20150101 VALUES LESS THAN (DATE '2015-01-01')
);
Maybe you want to group night time hours:
(
SUBPARTITION HOUR_NIGHT VALUES (0,1,2,3,4,5,6, 19,20,21,22,23),
SUBPARTITION HOUR07 VALUES (7),
SUBPARTITION HOUR08 VALUES (8),
SUBPARTITION HOUR11 VALUES (11),
...
SUBPARTITION HOUR17 VALUES (17),
SUBPARTITION HOUR18 VALUES (18)
)