[20130513]Interval Partition的一些问题.txt

Interval Partition管理是11G的新特性,简单了分区管理,本文简单探讨维护时遇到的问题.

1.建立测试环境:

export NLS_DATE_FORMAT='YYYY-MM-DD HH24:MI:SS'

SQL> @ver
BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production


CREATE TABLE t
(
  id number,
  create_date  date
)
partition by range(create_date) interval(numtoyminterval(1,'MONTH'))
(
  partition p201303 values less than (date '2013-03-01'),
  partition p201304 values less than (date '2013-04-01'),
  partition p201305 values less than (date '2013-05-01')
);

SQL> column high_value format a85

SQL> select partition_name, interval, high_value from dba_tab_partitions where table_owner=user and table_name = 'T' order by partition_position;

PARTITION_NAME                 INT HIGH_VALUE

------------------------------ --- -------------------------------------------------------------------------------------

P201303                        NO  TO_DATE(' 2013-03-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')

P201304                        NO  TO_DATE(' 2013-04-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')

P201305                        NO  TO_DATE(' 2013-05-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')

--可以发现interval=NO.

2.插入数据看看.

insert into t values(1 ,date'2013-05-11');

commit;

SQL> select partition_name, interval, high_value from dba_tab_partitions where table_owner=user and table_name = 'T' order by partition_position;

PARTITION_NAME                 INT HIGH_VALUE

------------------------------ --- -------------------------------------------------------------------------------------

P201303                        NO  TO_DATE(' 2013-03-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')

P201304                        NO  TO_DATE(' 2013-04-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')

P201305                        NO  TO_DATE(' 2013-05-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')

SYS_P3209                      YES TO_DATE(' 2013-06-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')

--可以发现建立一个新的分区. HIGH_VALUE=TO_DATE(' 2013-06-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN').

3.删除分区:

SQL> alter table t drop partition P201304;

Table altered.

SQL> alter table t drop partition P201305;

alter table t drop partition P201305

                             *

ERROR at line 1:

ORA-14758: Last partition in the range section cannot be dropped

--最后一个分区要删除如何处理呢?

4.简单一点是执行如下,先删除interval特性再建立:
alter table t set interval ();
然后在执行.
alter table t set interval (NUMTOYMINTERVAL(1,'month'));

自己测试一下,实际上执行如下:

alter table t set interval (NUMTOYMINTERVAL(1,'month'));

SQL> alter table t set interval (NUMTOYMINTERVAL(1,'month'));

Table altered.

SQL> select partition_name, interval, high_value from dba_tab_partitions where table_owner=user and table_name = 'T' order by partition_position;

PARTITION_NAME                 INT HIGH_VALUE

------------------------------ --- -------------------------------------------------------------------------------------

P201303                        NO  TO_DATE(' 2013-03-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')

P201305                        NO  TO_DATE(' 2013-05-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')

SYS_P3209                      NO  TO_DATE(' 2013-06-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')

SQL> alter table t drop partition P201305;

Table altered.

--这样就可以很好的解决这个问题.