Create table with Partition year and subpartition month In Oracle 12c - oracle

Question

I'm using Oracle 12c, I want to create a table with partition by year and subpartition by month. When I run the following code, it raise ORA-00922: missing or invalid option error. How can I fix it?
create table Log_his
(
ID NUMBER(20) not null,
Year number(4,0), -- Partition
Monthly number(2,0)), -- Subpartition
Log_reason VARCHAR2(5000),
Log_detail VARCHAR2(5000),
constraint PK_ID primary key (ID)
) PARTITION BY RANGE(Year) INTERVAL (1)
SUBPARTITION BY RANGE(Monthly)
SUBPARTITION TEMPLATE
(
SUBPARTITION January VALUES LESS THAN (02)tablespace MONTHLY_PARTITION,
SUBPARTITION February VALUES LESS THAN (03)tablespace MONTHLY_PARTITION,
SUBPARTITION March VALUES LESS THAN (04)tablespace MONTHLY_PARTITION,
SUBPARTITION April VALUES LESS THAN (05)tablespace MONTHLY_PARTITION,
SUBPARTITION May VALUES LESS THAN (06)tablespace MONTHLY_PARTITION,
SUBPARTITION June VALUES LESS THAN (07)tablespace MONTHLY_PARTITION,
SUBPARTITION July VALUES LESS THAN (08)tablespace MONTHLY_PARTITION,
SUBPARTITION August VALUES LESS THAN (09)tablespace MONTHLY_PARTITION,
SUBPARTITION September VALUES LESS THAN (10)tablespace MONTHLY_PARTITION,
SUBPARTITION October VALUES LESS THAN (11)tablespace MONTHLY_PARTITION,
SUBPARTITION November VALUES LESS THAN (12)tablespace MONTHLY_PARTITION,
SUBPARTITION December VALUES LESS THAN (MAXVALUE)
);
My purpose is create a table which auto create partition each year and It save log in 12 months. If I add one more month, the last month will be deleted and this will be done by daly job. How can I do that?
Thanks!

Answer 1

I would suggest to create simple monthly partition. You can do it like this:
create table Log_his
(
ID NUMBER(20) not null,
Year number(4,0),
Monthly number(2,0)),
Log_reason VARCHAR2(5000),-- Oracle default limit is VARCHAR2(4000)
Log_detail VARCHAR2(5000),
PARTITION_KEY TIMESTAMP(0) GENERATED ALWAYS AS (TO_TIMESTAMP(year||'-'||Monthly, 'YYYY-MM')) VIRTUAL,
constraint PK_ID primary key (ID)
)
PARTITION BY RANGE (PARTITION_KEY) INTERVAL (INTERVAL '1' MONTH)
(PARTITION P_INITIAL VALUES LESS THAN (TIMESTAMP '2018-01-01 00:00:00'));
New partitions will be added automatically. For maintenance you can create a procedure like below. You can run it by a daily job.
CREATE OR REPLACE PROCEDURE MaintainPartitions IS
CANNOT_DROP_LAST_PARTITION EXCEPTION;
PRAGMA EXCEPTION_INIT(CANNOT_DROP_LAST_PARTITION, -14758);
sqlstr VARCHAR2(10000);
ts TIMESTAMP;
newName VARCHAR2(30);
CURSOR TabPartitions IS
SELECT TABLE_NAME, PARTITION_NAME, HIGH_VALUE
FROM USER_TAB_PARTITIONS t
WHERE TABLE_NAME = 'LOG_HIS'
ORDER BY TABLE_NAME, PARTITION_POSITION;
BEGIN
FOR aPart IN TabPartitions LOOP
EXECUTE IMMEDIATE 'BEGIN :ret := '||aPart.HIGH_VALUE||'; END;' USING OUT ts;
ts := ADD_MONTHS(ts, -1);
newName := 'P_'||TO_CHAR(ts,'yyyy_fmmonth');
IF aPart.PARTITION_NAME <> newName THEN
sqlstr := 'ALTER TABLE '||aPart.TABLE_NAME||' RENAME PARTITION '||aPart.PARTITION_NAME||' TO '||newName;
EXECUTE IMMEDIATE sqlstr;
END IF;
END LOOP;
FOR aPart IN TabPartitions LOOP
BEGIN
EXECUTE IMMEDIATE 'BEGIN :ret := '||aPart.HIGH_VALUE||'; END;' USING OUT ts;
ts := ts - INTERVAL '1' DAY;
IF ts < ADD_MONTHS(SYSDATE, -12) THEN
sqlstr := 'ALTER TABLE '||aPart.TABLE_NAME||' DROP PARTITION '||aPart.PARTITION_NAME||' UPDATE GLOBAL INDEXES';
EXECUTE IMMEDIATE sqlstr;
END IF;
EXCEPTION
WHEN CANNOT_DROP_LAST_PARTITION THEN
EXECUTE IMMEDIATE 'ALTER TABLE '||aPart.TABLE_NAME||' SET INTERVAL ()';
EXECUTE IMMEDIATE 'ALTER TABLE '||aPart.TABLE_NAME||' DROP PARTITION ('||aPart.PARTITION_NAME||') UPDATE GLOBAL INDEXES';
EXECUTE IMMEDIATE 'ALTER TABLE '||aPart.TABLE_NAME||' SET INTERVAL (INTERVAL ''1'' MONTH)';
END;
END LOOP;
END MaintainPartitions;