为什么要创建oracle分区表？
一般情况下，如果不分区，则每次查询的对象都是一整张表，如果采用了表分区，那么可以根据具体的分区字段当作条件来避免扫描整张表，减少IO的扫描以提高表的查询速度。
新建(按照日期自动分区)分区表
SQL> create table test_partion(
2 pk_id number(38) generated as identity (start with 1 increment by 1),
3 P_day date,
4 words varchar2(200),
5 constraint pk_test_partition_id primary key (pk_id)
6 )
7 partition by range(P_day)
8 interval (numtodsinterval(1,'day'))
9 (
10 partition part_20170622 values less than (to_date('','yyyyMMdd'))
11 );
Table created
- 尝试插入数据，之后查看动态分区表的分区个数：
SQL> select * from test_partion ;
PK_ID P_DAY WORDS
--------------------------------------- ----------- ------
SQL> insert into test_partion (p_day,words) values (to_date('','yyyyMMdd'),'');
1 row inserted
SQL> insert into test_partion (p_day,words) values (to_date('','yyyyMMdd'),'');
1 row inserted
SQL> insert into test_partion (p_day,words) values (to_date('','yyyyMMdd'),'');
1 row inserted
SQL> insert into test_partion (p_day,words) values (to_date('','yyyyMMdd'),'');
1 row inserted
SQL> insert into test_partion (p_day,words) values (to_date('','yyyyMMdd'),'');
1 row inserted
SQL> insert into test_partion (p_day,words) values (to_date('','yyyyMMdd'),'');
1 row inserted
SQL> insert into test_partion (p_day,words) values (to_date('','yyyyMMdd'),'');
1 row inserted
SQL> insert into test_partion (p_day,words) values (to_date('','yyyyMMdd'),'');
1 row inserted
SQL> insert into test_partion (p_day,words) values (to_date('','yyyyMMdd'),'');
1 row inserted
SQL> insert into test_partion (p_day,words) values (to_date('','yyyyMMdd'),'');
1 row inserted
SQL> select table_name,partition_name,high_value from user_tab_partitions where table_name='TEST_PARTION';
TABLE_NAME PARTITION_NAME HIGH_VALUE
--------------- ---------------- --------------------------------------------------------------------------------
TEST_PARTION PART_20170622 TO_DATE(' 2017-06-22 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2252 TO_DATE(' 2017-06-23 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2253 TO_DATE(' 2017-06-24 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2254 TO_DATE(' 2017-06-25 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2255 TO_DATE(' 2017-06-26 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2256 TO_DATE(' 2017-06-27 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2257 TO_DATE(' 2017-06-28 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2258 TO_DATE(' 2017-06-29 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2259 TO_DATE(' 2017-06-30 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
9 rows selected
从上边表中我们基本可以看出，除了分区PART_20170622是我们动态创建的分区外，其他SYS_*分区都是动态创建的。
接下来查看每个分区表的数据分区情况：
SQL> select * from test_partion partition(PART_20170622);
PK_ID P_DAY WORDS
--------------------------------------- ----------- -------- SQL> select * from test_partion partition(SYS_P2252);
PK_ID P_DAY WORDS
--------------------------------------- ----------- --------
1 2017/6/22 00001 SQL> select * from test_partion partition(SYS_P2253);
PK_ID P_DAY WORDS
--------------------------------------- ----------- --------
2 2017/6/23 00002
3 2017/6/23 00003
5 2017/6/23 00005 SQL> select * from test_partion partition(SYS_P2254);
PK_ID P_DAY WORDS
--------------------------------------- ----------- -------
4 2017/6/24 00004 SQL> select * from test_partion partition(SYS_P2255);
PK_ID P_DAY WORDS
--------------------------------------- ----------- -------
6 2017/6/25 00006 SQL> select * from test_partion partition(SYS_P2256);
PK_ID P_DAY WORDS
--------------------------------------- ----------- -------
7 2017/6/26 00006 SQL> select * from test_partion partition(SYS_P2257);
PK_ID P_DAY WORDS
--------------------------------------- ----------- -------
8 2017/6/27 00006 SQL> select * from test_partion partition(SYS_P2258);
PK_ID P_DAY WORDS
--------------------------------------- ----------- -------
9 2017/6/28 00006 SQL> select * from test_partion partition(SYS_P2259);
PK_ID P_DAY WORDS
--------------------------------------- ----------- ------
10 2017/6/29 00006
分区操作：
1）删除某个分区表中的数据
SQL> delete from test_partion partition(SYS_P2259);
1 row deleted SQL> select * from test_partion partition(SYS_P2259);
PK_ID P_DAY WORDS
--------------------------------------- ----------- ------
2）删除某个分区
SQL> alter table test_partion drop partition SYS_P2259;
Table altered
删除分区之后，查看表分区情况。
SQL> select table_name,partition_name,high_value from user_tab_partitions where table_name='TEST_PARTION';
TABLE_NAME PARTITION_NAME HIGH_VALUE
--------------- ---------------- --------------------------------------------------------------------------------
TEST_PARTION PART_20170622 TO_DATE(' 2017-06-22 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2252 TO_DATE(' 2017-06-23 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2253 TO_DATE(' 2017-06-24 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2254 TO_DATE(' 2017-06-25 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2255 TO_DATE(' 2017-06-26 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2256 TO_DATE(' 2017-06-27 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2257 TO_DATE(' 2017-06-28 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2258 TO_DATE(' 2017-06-29 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
8 rows selected
注：drop partition时，该分区内存储的数据也将同时删除，你的本意是希望删除掉指定的分区但保留数据，你应该使用merge partition，执行该语句会导致glocal索引的失效需要重建全局索引
3）合并分区
相邻的分区可以通过命令merge partition合并为一个分区，同时分区中的数据也将会被合并到同一个分区中。
新分区的下边界为原来边界值较低的分区，上边界为原来边界值较高的分区，原先的局部索引相应也会合并，全局索引会失效，需要rebuild。
参考：http://www.cnblogs.com/wangfg/p/5286519.html
SQL> alter table test_partion merge partitions SYS_P2253,SYS_P2254 into partition SYS_P2253_to_P2254;
Table altered SQL> select table_name,partition_name,high_value from user_tab_partitions where table_name='TEST_PARTION';
TABLE_NAME PARTITION_NAME HIGH_VALUE
-------------------------------------------------------------------------------- -------------------------------------------------------------------------------- --------------------------------------------------------------------------------
TEST_PARTION PART_20170622 TO_DATE(' 2017-06-22 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2252 TO_DATE(' 2017-06-23 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2253_TO_P2254 TO_DATE(' 2017-06-25 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2255 TO_DATE(' 2017-06-26 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2256 TO_DATE(' 2017-06-27 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2257 TO_DATE(' 2017-06-28 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2258 TO_DATE(' 2017-06-29 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
7 rows selected SQL> select * from test_partion partition(SYS_P2253_TO_P2254);
PK_ID P_DAY WORDS
--------------------------------------- ----------- --------------------------------------------------------------------------------
2 2017/6/23 00002
3 2017/6/23 00003
5 2017/6/23 00005
4 2017/6/24 00004 SQL> insert into test_partion (p_day,words) values (to_date('20170623','yyyyMMdd'),'06665');
insert into test_partion (p_day,words) values (to_date('20170623','yyyyMMdd'),'06665')
ORA-01502: 索引 "NETPLAN_ONLINE_APPUSER.PK_TEST_PARTITION_ID" 或这类索引的分区处于不可用状态 SQL> alter index PK_TEST_PARTITION_ID rebuild;
Index altered SQL> insert into test_partion (p_day,words) values (to_date('20170623','yyyyMMdd'),'06665');
1 row inserted SQL> insert into test_partion (p_day,words) values (to_date('20170624','yyyyMMdd'),'06665');
1 row inserted SQL> select * from test_partion partition(SYS_P2253_TO_P2254);
PK_ID P_DAY WORDS
--------------------------------------- ----------- --------------------------------------------------------------------------------
2 2017/6/23 00002
3 2017/6/23 00003
5 2017/6/23 00005
4 2017/6/24 00004
12 2017/6/23 06665
13 2017/6/24 06665
6 rows selected
4）分区重命名
SQL>
SQL> alter table test_partion rename partition SYS_P2253_to_P2254 TO SYS_P2253_to_P2254___;
Table altered SQL> insert into test_partion (p_day,words) values (to_date('','yyyyMMdd'),'');
1 row inserted SQL> select table_name,partition_name,high_value from user_tab_partitions where table_name='TEST_PARTION';
TABLE_NAME PARTITION_NAME HIGH_VALUE
-------------------------------------------------------------------------------- -------------------------------------------------------------------------------- --------------------------------------------------------------------------------
TEST_PARTION PART_20170622 TO_DATE(' 2017-06-22 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2252 TO_DATE(' 2017-06-23 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2253_TO_P2254___ TO_DATE(' 2017-06-25 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2255 TO_DATE(' 2017-06-26 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2256 TO_DATE(' 2017-06-27 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2257 TO_DATE(' 2017-06-28 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
TEST_PARTION SYS_P2258 TO_DATE(' 2017-06-29 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA
7 rows selected SQL> insert into test_partion (p_day,words) values (to_date('20170624','yyyyMMdd'),'76665');
1 row inserted SQL> select * from test_partion partition(SYS_P2253_TO_P2254___);
PK_ID P_DAY WORDS
--------------------------------------- ----------- --------------------------------------------------------------------------------
2 2017/6/23 00002
3 2017/6/23 00003
5 2017/6/23 00005
4 2017/6/24 00004
12 2017/6/23 06665
13 2017/6/24 06665
14 2017/6/24 76665
15 2017/6/24 76665
8 rows selected
因为这里是动态分区，所以就不介绍怎么添加分区。