分区(Partition)一直是Oracle数据库引以为傲的一项技术，正是分区的存在让Oracle高效的处理海量数据成为可能，在Oracle 11g中，分区技术在易用性和可扩展性上再次得到了增强。在10g的Oracle版本中，要对分区表做调整，尤其是对RANGE分区添加新的分区都需要DBA手动定期添加，或都使用存储过程进行管理。在11G的版本中的Interval Partition不再需要DBA去干预新分区的添加，Oracle会自动去执行这样的操作，减少了DBA的工作量。Interval Partition是Range分区的一个扩展。
使用Interval Partition也有一些限制：
You can only specify one partitioning key column, and it must be of
NUMBERorDATEtype.Interval partitioning is not supported for index-organized tables.
You cannot create a domain index on an interval-partitioned table.
Interval Partition也可以创建复合分区：
Interval-range
Interval-hash
Interval-list
创建Interval分区表：
sys@ORCL>CREATE TABLE interval_sales
2 ( prod_id NUMBER(6)
3 , cust_id NUMBER
4 , time_id DATE
5 , channel_id CHAR(1)
6 , promo_id NUMBER(6)
7 , quantity_sold NUMBER(3)
8 , amount_sold NUMBER(10,2)
9 )
10 PARTITION BY RANGE (time_id)
11 INTERVAL(NUMTOYMINTERVAL(1, 'MONTH'))
12 ( PARTITION p0 VALUES LESS THAN (TO_DATE('1-1-2008', 'DD-MM-YYYY')),
13 PARTITION p1 VALUES LESS THAN (TO_DATE('1-1-2009', 'DD-MM-YYYY')),
14 PARTITION p2 VALUES LESS THAN (TO_DATE('1-7-2009', 'DD-MM-YYYY')),
15 PARTITION p3 VALUES LESS THAN (TO_DATE('1-1-2010', 'DD-MM-YYYY')) );
Table created. 插入在指定分区范围内的测试数据，数据插入成功
sys@ORCL>insert into interval_sales values(1,101,to_date('2008-06-01','yyyy-mm-dd'),'a',201,101,10);
1 row created.
sys@ORCL>commit;
Commit complete.
sys@ORCL>select * from interval_sales partition(p1);
PROD_ID CUST_ID TIME_ID CHA PROMO_ID QUANTITY_SOLD AMOUNT_SOLD
---------- ---------- ------------------- --- ---------- ------------- -----------
1 101 2008-06-01 00:00:00 a 201 101 10插入不在指定分区范围内的测试数据，数据插入成功
sys@ORCL>insert into interval_sales values(2,101,to_date('2010-01-03','yyyy-mm-dd'),'a',201,101,10);
1 row created.
sys@ORCL>commit;
Commit complete.
sys@ORCL>select * from interval_sales;
PROD_ID CUST_ID TIME_ID CHA PROMO_ID QUANTITY_SOLD AMOUNT_SOLD
---------- ---------- ------------------- --- ---------- ------------- -----------
1 101 2008-06-01 00:00:00 a 201 101 10
2 101 2010-01-03 00:00:00 a 201 101 10查看现在表的所有分区
sys@ORCL>col table_owner for a10
sys@ORCL>col table_name for a15
sys@ORCL>col partition_name for a20
sys@ORCL>col high_value for a100
sys@ORCL>set linesize 300
sys@ORCL>select table_owner,table_name,partition_name,high_value from dba_tab_partitions where table_name='INTERVAL_SALES';
TABLE_OWNE TABLE_NAME PARTITION_NAME HIGH_VALUE
---------- --------------- -------------------- ----------------------------------------------------------------------------------------------------
SYS INTERVAL_SALES P0 TO_DATE(' 2008-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES P1 TO_DATE(' 2009-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES P2 TO_DATE(' 2009-07-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES P3 TO_DATE(' 2010-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES SYS_P41 TO_DATE(' 2010-02-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')可以看到INTERVAL_sales表多了一个SYS_P41分区，分区的HIGH_VALUE为2010-02-01，分区是增加了一个月
再插入间隔再大一些的测试数据看看变化
sys@ORCL>insert into interval_sales values(2,101,to_date('2010-08-03','yyyy-mm-dd'),'a',201,101,10);
1 row created.
sys@ORCL>commit;
Commit complete.
sys@ORCL>select * from interval_sales;
PROD_ID CUST_ID TIME_ID CHA PROMO_ID QUANTITY_SOLD AMOUNT_SOLD
---------- ---------- ------------------- --- ---------- ------------- -----------
1 101 2008-06-01 00:00:00 a 201 101 10
2 101 2010-01-03 00:00:00 a 201 101 10
2 101 2010-08-03 00:00:00 a 201 101 10
sys@ORCL>select table_owner,table_name,partition_name,high_value from dba_tab_partitions where table_name='INTERVAL_SALES';
TABLE_OWNE TABLE_NAME PARTITION_NAME HIGH_VALUE
---------- --------------- -------------------- ----------------------------------------------------------------------------------------------------
SYS INTERVAL_SALES P0 TO_DATE(' 2008-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES P1 TO_DATE(' 2009-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES P2 TO_DATE(' 2009-07-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES P3 TO_DATE(' 2010-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES SYS_P41 TO_DATE(' 2010-02-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES SYS_P42 TO_DATE(' 2010-09-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
6 rows selected.
sys@ORCL>insert into interval_sales values(2,101,to_date('2010-05-03','yyyy-mm-dd'),'a',201,101,10);
1 row created.
sys@ORCL>commit;
Commit complete.
sys@ORCL>select * from interval_sales;
PROD_ID CUST_ID TIME_ID CHA PROMO_ID QUANTITY_SOLD AMOUNT_SOLD
---------- ---------- ------------------- --- ---------- ------------- -----------
1 101 2008-06-01 00:00:00 a 201 101 10
2 101 2010-01-03 00:00:00 a 201 101 10
2 101 2010-05-03 00:00:00 a 201 101 10
2 101 2010-08-03 00:00:00 a 201 101 10
sys@ORCL>select table_owner,table_name,partition_name,high_value from dba_tab_partitions where table_name='INTERVAL_SALES';
TABLE_OWNE TABLE_NAME PARTITION_NAME HIGH_VALUE
---------- --------------- -------------------- ----------------------------------------------------------------------------------------------------
SYS INTERVAL_SALES P0 TO_DATE(' 2008-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES P1 TO_DATE(' 2009-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES P2 TO_DATE(' 2009-07-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES P3 TO_DATE(' 2010-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES SYS_P41 TO_DATE(' 2010-02-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES SYS_P42 TO_DATE(' 2010-09-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
SYS INTERVAL_SALES SYS_P43 TO_DATE(' 2010-06-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')
7 rows selected.可以看出插入2010-08-03的数据会创建一个2010-09-01的分区，然后再插入2010-05-03的数据会创建2010-06-01的分区，说明所有自动创建的分区都会按整个月来控制。控制这个时间间隔的就是NUMTOYMINTERVAL(1, 'MONTH')。
NUMTOYMINTERVAL(1, 'YEAR') 一年
NUMTOYMINTERVAL(1, 'MONTH') 一个月
NUMTODSINTERVAL(1, 'DAY') 一天
NUMTODSINTERVAL(1, 'HOUR') 一小时
NUMTODSINTERVAL(1, 'MINUTE') 一分钟
NUMTODSINTERVAL(1, 'SECOND') 一秒
使用数值做分区键也可以使用Interval Partition
sys@ORCL>create table interval_num
2 (id number,
3 name varchar2(20),
4 time_id date
5 )
6 partition by range (id)
7 interval(20)
8 (partition p0 values less than (20));
Table created.
sys@ORCL>insert into interval_num values(1,'a',to_date('2016-01-01','yyyy-mm-dd'));
1 row created.
sys@ORCL>insert into interval_num values(21,'a',to_date('2016-01-01','yyyy-mm-dd'));
1 row created.
sys@ORCL>commit;
Commit complete.
sys@ORCL>select table_owner,table_name,partition_name,high_value from dba_tab_partitions where table_name='INTERVAL_NUM';
TABLE_OWNE TABLE_NAME PARTITION_NAME HIGH_VALUE
---------- --------------- -------------------- ----------------------------------------------------------------------------------------------------
SYS INTERVAL_NUM P0 20
SYS INTERVAL_NUM SYS_P44 40使用Interval Partition的注意事项，自动创建的分区名都是自动分配的，类似SYS_P**的，如果觉得这种名字不合规的话可以进行修改
sys@ORCL>alter table interval_num rename partition sys_p44 to p1;
Table altered.
sys@ORCL>select table_owner,table_name,partition_name,high_value from dba_tab_partitions where table_name='INTERVAL_NUM';
TABLE_OWNE TABLE_NAME PARTITION_NAME HIGH_VALUE
---------- --------------- -------------------- ----------------------------------------------------------------------------------------------------
SYS INTERVAL_NUM P0 20
SYS INTERVAL_NUM P1 40非Interval Partition转为Partition，使用alter table table_name set interval(...);
sys@ORCL> create table interval_num
2 (id number,
3 name varchar2(20),
4 time_id date
5 )
6 partition by range (id)
7 (partition p0 values less than (20));
Table created.
sys@ORCL>insert into interval_num(id) values(1);
1 row created.
sys@ORCL>insert into interval_num(id) values(21);
insert into interval_num(id) values(21)
*
ERROR at line 1:
ORA-14400: inserted partition key does not map to any partition
sys@ORCL>alter table interval_num set interval(20);
Table altered.
sys@ORCL>insert into interval_num(id) values(21);
1 row created.
sys@ORCL>select table_owner,table_name,partition_name,high_value from dba_tab_partitions where table_name='INTERVAL_NUM';
TABLE_OWNER TABLE_NAME PARTITION_ HIGH_VALUE
--------------- --------------- ---------- --------------------------------------------------------------------------------
SYS INTERVAL_NUM P0 20
SYS INTERVAL_NUM SYS_P45 40官方文档：http://docs.oracle.com/cd/E11882_01/server.112/e25523/part_admin001.htm#BAJHFFBE
