Oracle 学习之 性能优化(十二) 分区表

一、分区概念

Oracle允许将表、索引、索引组织表细分成更小的片，每个片我们称之为分区。分区有其自己的名字和存储参数。

如下图：

每行数据只能属于一个分区，分区键决定数据行属于哪个分区。分区键由一个或多个列组成。Oracle自动的将数据的DML操作映射到相应的分区中。

何时使用分区表：

• Tables greater than 2 GB should always be considered as candidates for partitioning.

• Tables containing historical data, in which new data is added into the newest partition. A typical example is a historical table where only the current month's data is updatable and the other 11 months are read only.

• When the contents of a table must be distributed across different types of storage devices.

何时使用分区索引：

• Avoid rebuilding the entire index when data is removed.

• Perform maintenance on parts of the data without invalidating the entire index.

• Reduce the effect of index skew caused by an index on a column with a monotonically increasing value.

分区的优点：

分区裁剪，DML操作的数据如果可以定位到某个或者某些分区，那么只需对这部分数据进行读写。

分区智能join，如果关联查询只需用到部分分区，那么避免了全表数据的扫描。

易于维护数据。

分区策略：

LIST、RANGE、HASH、SYSTEM、INTERVAL、reference、虚拟列分区。

表分区类型：

单级别分区

组合分区

索引分区类型：

本地分区

全局分区

全局索引

二、创建分区

创建LIST分区

SQL> CREATE TABLE accounts( id             NUMBER, account_number NUMBER, customer_id    NUMBER, branch_id      NUMBER, region         VARCHAR(2), status         VARCHAR2(1))PARTITION BY LIST (region)( PARTITION p_northwest VALUES ('OR', 'WA'), PARTITION p_southwest VALUES ('AZ', 'UT', 'NM'), PARTITION p_northeast VALUES ('NY', 'VM', 'NJ'), PARTITION p_southeast VALUES ('FL', 'GA'), PARTITION p_northcentral VALUES ('SD', 'WI'), PARTITION p_southcentral VALUES ('OK', 'TX'));Table created.SQL>

插入数据

SET DEFINE OFF;Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (378326946, 894594273, 1292607495, 142784215, 'OR',     'k');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (584618757, 1364130187, 438768827, 554439762, 'WA',     'o');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (41523719, 656248010, 469613013, 1849874408, 'OR',     'o');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1484487356, 1308908163, 1088179442, 1201623497, 'OR',     'w');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (151951677, 2077813008, 139635883, 1324220110, 'OR',     'L');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (537989506, 1256709056, 5665768, 1397516214, 'WA',     'j');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1054752157, 511468132, 2033193426, 183536554, 'WA',     'q');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (2038555798, 1761488065, 1281290484, 1134105071, 'OR',     'y');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1749170397, 1025971133, 1336822659, 219993587, 'OR',     'G');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1308900569, 1076156248, 496158144, 1160914382, 'OR',     'Z');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1742657481, 1697703100, 1276715127, 249769402, 'OR',     'g');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1730173163, 690868494, 420676729, 1001701868, 'OR',     'K');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1113431343, 1306177470, 912447414, 39868117, 'OR',     'b');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1813999643, 1738970302, 98672809, 54100636, 'OR',     'M');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (60561891, 1229089094, 1626776049, 1373758116, 'OR',     'l');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1194099877, 966075960, 973792659, 106417526, 'WA',     'E');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (972828393, 1964561103, 715385951, 581092182, 'AZ',     'f');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1387745036, 811991623, 884849418, 924597781, 'AZ',     'B');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (4042014, 1008692733, 524884932, 755313715, 'NM',     'U');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (9035402, 85439893, 333606312, 233856899, 'UT',     'j');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (300439305, 809521660, 602721207, 1167124218, 'UT',     'C');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1261574467, 1642196402, 1309279369, 811128713, 'AZ',     'Z');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1734634260, 1893138191, 36547218, 1696588381, 'AZ',     'd');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1393860542, 207139753, 1053973916, 2015424087, 'NM',     'L');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1104007962, 703835058, 1058040433, 973595416, 'NM',     'X');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1829413354, 1360120309, 475884296, 275389923, 'NM',     'o');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (644314976, 1910013550, 770148070, 1201992324, 'AZ',     'B');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (1479078753, 501738145, 2081089479, 1365686422, 'NM',     'H');Insert into SCOTT.ACCOUNTS   (ID, ACCOUNT_NUMBER, CUSTOMER_ID, BRANCH_ID, REGION,     STATUS) Values   (340748485, 1276107083, 11726459, 1736071185, 'NM',     'k');COMMIT;

查询分区中的数据

SQL> select count(*) from accounts;  COUNT(*)----------        29SQL> select count(*) from accounts partition(p_northwest);   COUNT(*)----------        16SQL> select count(*) from accounts PARTITION (p_southwest);  COUNT(*)----------        13SQL> select count(*) from accounts PARTITION (p_northeast);  COUNT(*)----------         0

分区裁剪测试

SQL> set autotrace onSQL> select count(*) from  accounts where REGION='AZ';  COUNT(*)----------         5Execution Plan----------------------------------------------------------Plan hash value: 3505378---------------------------------------------------------------------------------------------------| Id  | Operation          | Name     | Rows  | Bytes | Cost (%CPU)| Time   | Pstart| Pstop |---------------------------------------------------------------------------------------------------|   0 | SELECT STATEMENT       |         |   1 |        3 |    14   (0)| 00:00:01 |     |     ||   1 |  SORT AGGREGATE        |       |   1 |        3 |               |       |     |     ||   2 |   PARTITION LIST SINGLE|     |   5 |    15 |    14   (0)| 00:00:01 |   KEY |   KEY ||*  3 |    TABLE ACCESS FULL   | ACCOUNTS |       5 |    15 |    14   (0)| 00:00:01 |  2 |        2 |---------------------------------------------------------------------------------------------------

由执行计划中可以看出，Oracle只查询了一个分区的数据。

创建RANGE分区

CREATE TABLE SALES(  PROD_ID        NUMBER        NOT NULL,  CUST_ID        NUMBER        NOT NULL,  TIME_ID        DATE          NOT NULL,  CHANNEL_ID     NUMBER        NOT NULL,  PROMO_ID       NUMBER        NOT NULL,  QUANTITY_SOLD  NUMBER(10,2)  NOT NULL,  AMOUNT_SOLD    NUMBER(10,2)  NOT NULL)PARTITION BY RANGE (TIME_ID)(      PARTITION SALES_Q1_2003 VALUES LESS THAN (TO_DATE('2003-04-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS')),  PARTITION SALES_Q2_2003 VALUES LESS THAN (TO_DATE('2003-07-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS')) ,    PARTITION SALES_Q3_2003 VALUES LESS THAN (TO_DATE('2003-10-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS')),    PARTITION SALES_Q4_2003 VALUES LESS THAN (TO_DATE('2004-01-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS')));

11g新增了一个时间间隔分区，本质上是RANGE分区的一个扩展。

CREATE TABLE SALES2(  PROD_ID        NUMBER        NOT NULL,  CUST_ID        NUMBER        NOT NULL,  TIME_ID        DATE          NOT NULL,  CHANNEL_ID     NUMBER        NOT NULL,  PROMO_ID       NUMBER        NOT NULL,  QUANTITY_SOLD  NUMBER(10,2)  NOT NULL,  AMOUNT_SOLD    NUMBER(10,2)  NOT NULL)PARTITION BY RANGE (TIME_ID) INTERVAL(NUMTOYMINTERVAL(3,'MONTH'))(      PARTITION SALES_Q1_2003 VALUES LESS THAN (TO_DATE('2003-04-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS')));

时间间隔分区会自动根据数据维护分区。我们做如下数据插入

SET DEFINE OFF;Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (15, 519, TO_DATE('01/25/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 1003.49);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (32, 12824, TO_DATE('03/13/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 73.43);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (47, 3289, TO_DATE('01/15/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 4, 999,     1, 29.89);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (116, 2945, TO_DATE('09/23/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 14.35);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (48, 1580, TO_DATE('12/24/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 13.13);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (19, 2671, TO_DATE('03/16/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 4, 999,     1, 52.4);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (142, 6834, TO_DATE('02/02/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 25.4);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (33, 5579, TO_DATE('07/23/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 2, 999,     1, 45.71);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (35, 10985, TO_DATE('08/20/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 59.78);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (28, 13125, TO_DATE('10/13/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 2, 999,     1, 203.18);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (46, 6719, TO_DATE('10/10/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 25.83);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (23, 33729, TO_DATE('01/16/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 2, 999,     1, 23.51);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (23, 9927, TO_DATE('03/28/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 23.19);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (118, 818, TO_DATE('01/24/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 2, 999,     1, 8.86);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (135, 5860, TO_DATE('02/27/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 55.43);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (41, 2292, TO_DATE('04/13/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 2, 999,     1, 48.78);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (30, 7859, TO_DATE('07/14/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 10.48);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (128, 3266, TO_DATE('07/15/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 30.07);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (145, 3461, TO_DATE('10/27/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 13.76);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (24, 9170, TO_DATE('02/07/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 351,     1, 63.97);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (118, 1156, TO_DATE('01/29/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 4, 999,     1, 17.53);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (26, 11267, TO_DATE('06/10/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 2, 999,     1, 156.71);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (31, 8630, TO_DATE('04/02/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 8.95);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (23, 392, TO_DATE('08/30/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 4, 999,     1, 21.22);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (47, 280, TO_DATE('08/13/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 2, 999,     1, 29.02);Insert into SALES2   (PROD_ID, CUST_ID, TIME_ID, CHANNEL_ID, PROMO_ID,     QUANTITY_SOLD, AMOUNT_SOLD) Values   (119, 6822, TO_DATE('08/06/2003 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 3, 999,     1, 7.31);COMMIT;

现在我们查看sales2的分区情况

SQL> SELECT TABLE_NAME, PARTITION_NAME      FROM dba_tab_partitions    WHERE TABLE_OWNER = 'SCOTT' AND TABLE_NAME = 'SALES2';TABLE_NAME                     PARTITION_NAME------------------------------ ------------------------------SALES2                         SALES_Q1_2003SALES2                         SYS_P41SALES2                         SYS_P42SALES2                         SYS_P43

可见系统根据数据的实际情况，给我们新建了3个分区，分区由系统自命名。

创建HASH分区

CREATE TABLE sales_hash  (s_productid  NUMBER,   s_saledate   DATE,   s_custid     NUMBER,   s_totalprice NUMBER)PARTITION BY HASH(s_productid)( PARTITION p1 TABLESPACE users, PARTITION p2 TABLESPACE users, PARTITION p3 TABLESPACE users, PARTITION p4 TABLESPACE users);

根据s_productionid的值，算出hash值，将对于的数据行插入到相应的分区中。各分区数据要想分别均匀，分区的个数为2的次方数。

创建SYSTEM分区

此分区与其他的都不同，数据插入到哪个分区与数据本身无关，完全有用户自定义。

CREATE TABLE t_system(   id     NUMBER,   name   VARCHAR2 (30))PARTITION BY SYSTEM (PARTITION p1, PARTITION p2, PARTITION p3, PARTITION p4);

此时往表中直接插入数据就会报错

SQL> insert into t_system(id,name)values(1,'kevin');insert into t_system(id,name)values(1,'kevin')            *ERROR at line 1:ORA-14701: partition-extended name or bind variable must be used for DMLs on tables partitioned by the System method

插入数据，必须指定分区名称

SQL> insert into t_system partition(p1)(id,name)values(1,'kevin');1 row created.

并且重复数据可以插入到不同的分区

SQL>  insert into t_system partition(p2)(id,name)values(1,'kevin');1 row created.

创建虚拟列分区

Oracle11g新增了虚拟列功能，虚拟列的值从其他的列推导而来，Oracle只保存源数据，这个列不占存储空间。虚拟列其中一个引申功能就是虚拟列分区功能。11g增加对虚拟列的支持，这使得分区功能更加灵活。如：表中有一个日期列，希望根据日期列进行分区，每个月份一个分区，总共12个分区，不管是哪一年的，只要是那个月，就放在那个月的分区中。

CREATE TABLE T_PARTITION_MONTH(   ID                NUMBER,   NAME              VARCHAR2 (30),   CREATE_DATE       DATE,   PARTITION_MONTH   AS (TO_NUMBER (TO_CHAR (CREATE_DATE, 'MM'))))PARTITION BY LIST   (PARTITION_MONTH)   (      PARTITION P1 VALUES (1),      PARTITION P2 VALUES (2),      PARTITION P3 VALUES (3),      PARTITION P4 VALUES (4),      PARTITION P5 VALUES (5),      PARTITION P6 VALUES (6),      PARTITION P7 VALUES (7),      PARTITION P8 VALUES (8),      PARTITION P9 VALUES (9),      PARTITION P10 VALUES (10),      PARTITION P11 VALUES (11),      PARTITION P12 VALUES (12));

创建参考列分区

子表的分区依赖于父表，我们看如下例子

CREATE TABLE orders    ( order_id           NUMBER(12),      order_date         TIMESTAMP,      order_mode         VARCHAR2(8),      customer_id        NUMBER(6),      order_status       NUMBER(2),      order_total        NUMBER(8,2),      sales_rep_id       NUMBER(6),      promotion_id       NUMBER(6),      CONSTRAINT orders_pk PRIMARY KEY(order_id)    )  PARTITION BY RANGE(order_date)    ( PARTITION Q1_2005 VALUES LESS THAN (TO_DATE('01-APR-2005','DD-MON-YYYY')),      PARTITION Q2_2005 VALUES LESS THAN (TO_DATE('01-JUL-2005','DD-MON-YYYY')),      PARTITION Q3_2005 VALUES LESS THAN (TO_DATE('01-OCT-2005','DD-MON-YYYY')),      PARTITION Q4_2005 VALUES LESS THAN (TO_DATE('01-JAN-2006','DD-MON-YYYY'))    );

订单表，按order_date做范围分区。

CREATE TABLE order_items    ( order_id           NUMBER(12) NOT NULL,      line_item_id       NUMBER(3)  NOT NULL,      product_id         NUMBER(6)  NOT NULL,      unit_price         NUMBER(8,2),      quantity           NUMBER(8),      CONSTRAINT order_items_fk      FOREIGN KEY(order_id) REFERENCES orders(order_id)    )    PARTITION BY REFERENCE(order_items_fk);

订单项目表，该表分区参考主表。

查看order_items的分区信息

SQL> SELECT TABLE_NAME, PARTITION_NAME  FROM DBA_TAB_PARTITIONS WHERE TABLE_NAME = 'ORDER_ITEMS';TABLE_NAME                     PARTITION_NAME------------------------------ ------------------------------ORDER_ITEMS                    Q1_2005ORDER_ITEMS                    Q2_2005ORDER_ITEMS                    Q3_2005ORDER_ITEMS                    Q4_2005

对于range和hash分区，你可以指定多列作为分区键。列数最多16个。

CREATE TABLE sales_demo (   year          NUMBER,    month         NUMBER,   day           NUMBER,   amount_sold   NUMBER) PARTITION BY RANGE (year,month)   (PARTITION before2001 VALUES LESS THAN (2001,1),   PARTITION q1_2001    VALUES LESS THAN (2001,4),   PARTITION q2_2001    VALUES LESS THAN (2001,7),   PARTITION q3_2001    VALUES LESS THAN (2001,10),   PARTITION q4_2001    VALUES LESS THAN (2002,1),   PARTITION future     VALUES LESS THAN (MAXVALUE,0));REM  12-DEC-2000INSERT INTO sales_demo VALUES(2000,12,12, 1000);REM  17-MAR-2001INSERT INTO sales_demo VALUES(2001,3,17, 2000);REM  1-NOV-2001INSERT INTO sales_demo VALUES(2001,11,1, 5000);REM  1-JAN-2002INSERT INTO sales_demo VALUES(2002,1,1, 4000);

组合分区有如下六种：

RANGE-RANGE、RANGE-LIST、RANGE-HASH、LIST-RANGE、LIST-LIST、LIST-HASH 。

组合分区的创建与单分区类似。

创建RANGE-RANGE组合分区

CREATE TABLE shipments( order_id      NUMBER NOT NULL, order_date    DATE NOT NULL, delivery_date DATE NOT NULL, customer_id   NUMBER NOT NULL, sales_amount  NUMBER NOT NULL)PARTITION BY RANGE (order_date)SUBPARTITION BY RANGE (delivery_date)( PARTITION p_2006_jul VALUES LESS THAN (TO_DATE('01-AUG-2006','dd-MON-yyyy'))  ( SUBPARTITION p06_jul_e VALUES LESS THAN (TO_DATE('15-AUG-2006','dd-MON-yyyy'))  , SUBPARTITION p06_jul_a VALUES LESS THAN (TO_DATE('01-SEP-2006','dd-MON-yyyy'))  , SUBPARTITION p06_jul_l VALUES LESS THAN (MAXVALUE)  ), PARTITION p_2006_aug VALUES LESS THAN (TO_DATE('01-SEP-2006','dd-MON-yyyy'))  ( SUBPARTITION p06_aug_e VALUES LESS THAN (TO_DATE('15-SEP-2006','dd-MON-yyyy'))  , SUBPARTITION p06_aug_a VALUES LESS THAN (TO_DATE('01-OCT-2006','dd-MON-yyyy'))  , SUBPARTITION p06_aug_l VALUES LESS THAN (MAXVALUE)  ), PARTITION p_2006_sep VALUES LESS THAN (TO_DATE('01-OCT-2006','dd-MON-yyyy'))  ( SUBPARTITION p06_sep_e VALUES LESS THAN (TO_DATE('15-OCT-2006','dd-MON-yyyy'))  , SUBPARTITION p06_sep_a VALUES LESS THAN (TO_DATE('01-NOV-2006','dd-MON-yyyy'))  , SUBPARTITION p06_sep_l VALUES LESS THAN (MAXVALUE)  ), PARTITION p_2006_oct VALUES LESS THAN (TO_DATE('01-NOV-2006','dd-MON-yyyy'))  ( SUBPARTITION p06_oct_e VALUES LESS THAN (TO_DATE('15-NOV-2006','dd-MON-yyyy'))  , SUBPARTITION p06_oct_a VALUES LESS THAN (TO_DATE('01-DEC-2006','dd-MON-yyyy'))  , SUBPARTITION p06_oct_l VALUES LESS THAN (MAXVALUE)  ), PARTITION p_2006_nov VALUES LESS THAN (TO_DATE('01-DEC-2006','dd-MON-yyyy'))  ( SUBPARTITION p06_nov_e VALUES LESS THAN (TO_DATE('15-DEC-2006','dd-MON-yyyy'))  , SUBPARTITION p06_nov_a VALUES LESS THAN (TO_DATE('01-JAN-2007','dd-MON-yyyy'))  , SUBPARTITION p06_nov_l VALUES LESS THAN (MAXVALUE)  ), PARTITION p_2006_dec VALUES LESS THAN (TO_DATE('01-JAN-2007','dd-MON-yyyy'))  ( SUBPARTITION p06_dec_e VALUES LESS THAN (TO_DATE('15-JAN-2007','dd-MON-yyyy'))  , SUBPARTITION p06_dec_a VALUES LESS THAN (TO_DATE('01-FEB-2007','dd-MON-yyyy'))  , SUBPARTITION p06_dec_l VALUES LESS THAN (MAXVALUE)  ));

查看分区信息

SQL> SELECT TABLE_NAME, PARTITION_NAME,SUBPARTITION_COUNT  FROM DBA_TAB_PARTITIONS WHERE TABLE_NAME = 'SHIPMENTS';   TABLE_NAME                     PARTITION_NAME                      SUBPARTITION_COUNT------------------------------ ------------------------------ ------------------SHIPMENTS                      P_2006_JUL                                   3SHIPMENTS                      P_2006_AUG                                   3SHIPMENTS                      P_2006_SEP                                   3SHIPMENTS                      P_2006_OCT                                   3SHIPMENTS                      P_2006_NOV                                   3SHIPMENTS                      P_2006_DEC                                   36 rows selected.

查看子分区信息

SQL>  SELECT TABLE_NAME, PARTITION_NAME,SUBPARTITION_NAME   FROM DBA_TAB_SUBPARTITIONS WHERE TABLE_NAME = 'SHIPMENTS'; TABLE_NAME                     PARTITION_NAME                      SUBPARTITION_NAME------------------------------ ------------------------------ ------------------------------SHIPMENTS                      P_2006_DEC                  P06_DEC_ESHIPMENTS                      P_2006_DEC                  P06_DEC_ASHIPMENTS                      P_2006_DEC                  P06_DEC_LSHIPMENTS                      P_2006_NOV                  P06_NOV_ESHIPMENTS                      P_2006_NOV                  P06_NOV_ASHIPMENTS                      P_2006_NOV                  P06_NOV_LSHIPMENTS                      P_2006_OCT                  P06_OCT_ESHIPMENTS                      P_2006_OCT                  P06_OCT_ASHIPMENTS                      P_2006_OCT                  P06_OCT_LSHIPMENTS                      P_2006_SEP                  P06_SEP_ESHIPMENTS                      P_2006_SEP                  P06_SEP_ATABLE_NAME                     PARTITION_NAME                      SUBPARTITION_NAME------------------------------ ------------------------------ ------------------------------SHIPMENTS                      P_2006_SEP                  P06_SEP_LSHIPMENTS                      P_2006_AUG                  P06_AUG_ESHIPMENTS                      P_2006_AUG                  P06_AUG_ASHIPMENTS                      P_2006_AUG                  P06_AUG_LSHIPMENTS                      P_2006_JUL                  P06_JUL_ESHIPMENTS                      P_2006_JUL                  P06_JUL_ASHIPMENTS                      P_2006_JUL                  P06_JUL_L18 rows selected.

创建RANGE-LIST

CREATE TABLE quarterly_regional_sales      (deptno number, item_no varchar2(20),       txn_date date, txn_amount number, state varchar2(2))  TABLESPACE ts4  PARTITION BY RANGE (txn_date)    SUBPARTITION BY LIST (state)      (PARTITION q1_1999 VALUES LESS THAN (TO_DATE('1-APR-1999','DD-MON-YYYY'))         (SUBPARTITION q1_1999_northwest VALUES ('OR', 'WA'),          SUBPARTITION q1_1999_southwest VALUES ('AZ', 'UT', 'NM'),          SUBPARTITION q1_1999_northeast VALUES ('NY', 'VM', 'NJ'),          SUBPARTITION q1_1999_southeast VALUES ('FL', 'GA'),          SUBPARTITION q1_1999_northcentral VALUES ('SD', 'WI'),          SUBPARTITION q1_1999_southcentral VALUES ('OK', 'TX')         ),       PARTITION q2_1999 VALUES LESS THAN ( TO_DATE('1-JUL-1999','DD-MON-YYYY'))         (SUBPARTITION q2_1999_northwest VALUES ('OR', 'WA'),          SUBPARTITION q2_1999_southwest VALUES ('AZ', 'UT', 'NM'),          SUBPARTITION q2_1999_northeast VALUES ('NY', 'VM', 'NJ'),          SUBPARTITION q2_1999_southeast VALUES ('FL', 'GA'),          SUBPARTITION q2_1999_northcentral VALUES ('SD', 'WI'),          SUBPARTITION q2_1999_southcentral VALUES ('OK', 'TX')         ),       PARTITION q3_1999 VALUES LESS THAN (TO_DATE('1-OCT-1999','DD-MON-YYYY'))         (SUBPARTITION q3_1999_northwest VALUES ('OR', 'WA'),          SUBPARTITION q3_1999_southwest VALUES ('AZ', 'UT', 'NM'),          SUBPARTITION q3_1999_northeast VALUES ('NY', 'VM', 'NJ'),          SUBPARTITION q3_1999_southeast VALUES ('FL', 'GA'),          SUBPARTITION q3_1999_northcentral VALUES ('SD', 'WI'),          SUBPARTITION q3_1999_southcentral VALUES ('OK', 'TX')         ),       PARTITION q4_1999 VALUES LESS THAN ( TO_DATE('1-JAN-2000','DD-MON-YYYY'))         (SUBPARTITION q4_1999_northwest VALUES ('OR', 'WA'),          SUBPARTITION q4_1999_southwest VALUES ('AZ', 'UT', 'NM'),          SUBPARTITION q4_1999_northeast VALUES ('NY', 'VM', 'NJ'),          SUBPARTITION q4_1999_southeast VALUES ('FL', 'GA'),          SUBPARTITION q4_1999_northcentral VALUES ('SD', 'WI'),          SUBPARTITION q4_1999_southcentral VALUES ('OK', 'TX')         )      );

创建RANGE-HASH分区

CREATE TABLE sales  ( prod_id       NUMBER(6)  , cust_id       NUMBER  , time_id       DATE  , channel_id    CHAR(1)  , promo_id      NUMBER(6)  , quantity_sold NUMBER(3)  , amount_sold   NUMBER(10,2)  ) PARTITION BY RANGE (time_id) SUBPARTITION BY HASH (cust_id)  SUBPARTITIONS 8 STORE IN (ts1, ts2, ts3, ts4) ( PARTITION sales_q1_2006 VALUES LESS THAN (TO_DATE('01-APR-2006','dd-MON-yyyy')) , PARTITION sales_q2_2006 VALUES LESS THAN (TO_DATE('01-JUL-2006','dd-MON-yyyy')) , PARTITION sales_q3_2006 VALUES LESS THAN (TO_DATE('01-OCT-2006','dd-MON-yyyy')) , PARTITION sales_q4_2006 VALUES LESS THAN (TO_DATE('01-JAN-2007','dd-MON-yyyy')) );

子分区也可以指定模板

如下：

CREATE TABLE sales_range_range  ( prod_id       NUMBER(6)  , cust_id       NUMBER  , time_id       DATE  , channel_id    CHAR(1)  , promo_id      NUMBER(6)  , quantity_sold NUMBER(3)  , amount_sold   NUMBER(10,2)  ) PARTITION BY RANGE (time_id) INTERVAL (NUMTODSINTERVAL(1,'DAY'))SUBPARTITION BY RANGE(amount_sold)   SUBPARTITION TEMPLATE   ( SUBPARTITION p_low VALUES LESS THAN (1000)   , SUBPARTITION p_medium VALUES LESS THAN (4000)   , SUBPARTITION p_high VALUES LESS THAN (8000)   , SUBPARTITION p_ultimate VALUES LESS THAN (maxvalue)   ) ( PARTITION before_2000 VALUES LESS THAN (TO_DATE('01-JAN-2000','dd-MON-yyyy')))或者CREATE TABLE sales_range_range  ( prod_id       NUMBER(6)  , cust_id       NUMBER  , time_id       DATE  , channel_id    CHAR(1)  , promo_id      NUMBER(6)  , quantity_sold NUMBER(3)  , amount_sold   NUMBER(10,2)  ) PARTITION BY RANGE (time_id)SUBPARTITION BY RANGE(amount_sold)   SUBPARTITION TEMPLATE   ( SUBPARTITION p_low VALUES LESS THAN (1000)   , SUBPARTITION p_medium VALUES LESS THAN (4000)   , SUBPARTITION p_high VALUES LESS THAN (8000)   , SUBPARTITION p_ultimate VALUES LESS THAN (maxvalue)   ) ( PARTITION before_2000 VALUES LESS THAN (TO_DATE('01-JAN-2000','dd-MON-yyyy')))

CREATE TABLE emp_sub_template (deptno NUMBER, empname VARCHAR(32), grade NUMBER)     PARTITION BY RANGE(deptno) SUBPARTITION BY HASH(empname)     SUBPARTITION TEMPLATE         (SUBPARTITION a TABLESPACE ts1,          SUBPARTITION b TABLESPACE ts2,          SUBPARTITION c TABLESPACE ts3,          SUBPARTITION d TABLESPACE ts4         )    (PARTITION p1 VALUES LESS THAN (1000),     PARTITION p2 VALUES LESS THAN (2000),     PARTITION p3 VALUES LESS THAN (MAXVALUE)    );

CREATE TABLE stripe_regional_sales            ( deptno number, item_no varchar2(20),              txn_date date, txn_amount number, state varchar2(2))   PARTITION BY RANGE (txn_date)   SUBPARTITION BY LIST (state)   SUBPARTITION TEMPLATE       (SUBPARTITION northwest VALUES ('OR', 'WA') TABLESPACE tbs_1,       SUBPARTITION southwest VALUES ('AZ', 'UT', 'NM') TABLESPACE tbs_2,       SUBPARTITION northeast VALUES ('NY', 'VM', 'NJ') TABLESPACE tbs_3,       SUBPARTITION southeast VALUES ('FL', 'GA') TABLESPACE tbs_4,       SUBPARTITION midwest VALUES ('SD', 'WI') TABLESPACE tbs_5,       SUBPARTITION south VALUES ('AL', 'AK') TABLESPACE tbs_6,       SUBPARTITION others VALUES (DEFAULT ) TABLESPACE tbs_7      )  (PARTITION q1_1999 VALUES LESS THAN ( TO_DATE('01-APR-1999','DD-MON-YYYY')),   PARTITION q2_1999 VALUES LESS THAN ( TO_DATE('01-JUL-1999','DD-MON-YYYY')),   PARTITION q3_1999 VALUES LESS THAN ( TO_DATE('01-OCT-1999','DD-MON-YYYY')),   PARTITION q4_1999 VALUES LESS THAN ( TO_DATE('1-JAN-2000','DD-MON-YYYY'))  );

创建分区索引

本地索引

SQL> create index idx_accounts_number on accounts(account_number) local;Index created.

创建索引时，添加local关键字，即为表的每个分区单独创建一个索引。

SQL> select index_name,partition_name from dba_ind_partitions where index_name='IDX_ACCOUNTS_NUMBER';INDEX_NAME                     PARTITION_NAME------------------------------ ------------------------------IDX_ACCOUNTS_NUMBER            P_NORTHCENTRALIDX_ACCOUNTS_NUMBER            P_NORTHEASTIDX_ACCOUNTS_NUMBER            P_NORTHWESTIDX_ACCOUNTS_NUMBER            P_SOUTHCENTRALIDX_ACCOUNTS_NUMBER            P_SOUTHEASTIDX_ACCOUNTS_NUMBER            P_SOUTHWEST6 rows selected.

可见，表有几个分区，就创建几个索引分区。

全局索引

创建方法与普通索引一致。

SQL> create index idx_accounts_id on accounts(id);Index created.

SQL> select index_name,partition_name from dba_ind_partitions where index_name='IDX_ACCOUNTS_ID';no rows selected

索引没有分区。

全局分区索引

SQL> create index idx_accounts_customer_id      on accounts(customer_id)      global partition by hash(customer_id)     partitions 4;Index created.

SQL>  select index_name,partition_name from dba_ind_partitions where index_name='IDX_ACCOUNTS_CUSTOMER_ID';INDEX_NAME                     PARTITION_NAME------------------------------ ------------------------------IDX_ACCOUNTS_CUSTOMER_ID       SYS_P61IDX_ACCOUNTS_CUSTOMER_ID       SYS_P62IDX_ACCOUNTS_CUSTOMER_ID       SYS_P63IDX_ACCOUNTS_CUSTOMER_ID       SYS_P64

三、维护分区

添加分区

LIST分区

SQL> ALTER TABLE accounts   ADD PARTITION p_nonmainland VALUES ('HI', 'PR');  Table altered.SQL>

RANGE分区

SQL> ALTER TABLE sales   ADD PARTITION sale_q1_2004      VALUES LESS THAN (TO_DATE ('2004-04-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS'));Table altered.SQL>

HASH分区

SQL> ALTER TABLE sales_hash ADD PARTITION; Table altered.

对于组合分区

SQL> ALTER TABLE shipments   ADD PARTITION p_2007_jan      VALUES LESS THAN (TO_DATE('01-FEB-2007','dd-MON-yyyy'));Table altered.

如果添加分区时，不指定子分区，那么系统默认帮你建立一个子分区

SQL>  SELECT TABLE_NAME, PARTITION_NAME,SUBPARTITION_NAME   FROM DBA_TAB_SUBPARTITIONS WHERE TABLE_NAME = 'SHIPMENTS' and PARTITION_NAME='P_2007_JAN';TABLE_NAME                     PARTITION_NAME                      SUBPARTITION_NAME------------------------------ ------------------------------ ------------------------------SHIPMENTS                      P_2007_JAN                  SYS_SUBP82

添加分区时，也可以指定子分区

SQL> ALTER TABLE shipments   ADD PARTITION p_2008_jan      VALUES LESS THAN (TO_DATE('01-FEB-2008','dd-MON-yyyy'))       ( SUBPARTITION p07_jan_e VALUES LESS THAN (TO_DATE('15-FEB-2007','dd-MON-yyyy'))      , SUBPARTITION p07_jan_a VALUES LESS THAN (TO_DATE('01-MAR-2007','dd-MON-yyyy'))      , SUBPARTITION p07_jan_l VALUES LESS THAN (TO_DATE('01-APR-2007','dd-MON-yyyy'))      ) ; Table altered.

此时子分区信息如下

SQL>  SELECT TABLE_NAME, PARTITION_NAME,SUBPARTITION_NAME   FROM DBA_TAB_SUBPARTITIONS WHERE TABLE_NAME = 'SHIPMENTS' and PARTITION_NAME='P_2008_JAN';  TABLE_NAME                     PARTITION_NAME                      SUBPARTITION_NAME------------------------------ ------------------------------ ------------------------------SHIPMENTS                      P_2008_JAN                  P07_JAN_ESHIPMENTS                      P_2008_JAN                  P07_JAN_ASHIPMENTS                      P_2008_JAN                  P07_JAN_L

如果组合分区的子分区指定了模板，那么添加分区时，无需指定子分区。

SQL> ALTER TABLE SALES_RANGE_RANGE   ADD PARTITION P_2000      VALUES LESS THAN (TO_DATE ('01-JAN-2001', 'dd-MON-yyyy'));  Table altered.

查看分区信息

SQL>  SELECT TABLE_NAME, PARTITION_NAME,SUBPARTITION_NAME   FROM DBA_TAB_SUBPARTITIONS WHERE TABLE_NAME = 'SALES_RANGE_RANGE' and PARTITION_NAME='P_2000'; TABLE_NAME                     PARTITION_NAME                      SUBPARTITION_NAME------------------------------ ------------------------------ ------------------------------SALES_RANGE_RANGE              P_2000                              P_2000_P_LOWSALES_RANGE_RANGE              P_2000                              P_2000_P_MEDIUMSALES_RANGE_RANGE              P_2000                              P_2000_P_HIGHSALES_RANGE_RANGE              P_2000                              P_2000_P_ULTIMATE

删除分区

Use one of the following statements to drop a table partition or subpartition:

• ALTER TABLE ... DROP PARTITION to drop a table partition

• ALTER TABLE ... DROP SUBPARTITION to drop a subpartition of a composite *-[range | list] partitioned table

SQL> ALTER TABLE SALES DROP PARTITION SALE_Q1_2004; Table altered.

删除子分区

SQL> alter table sales_range_range drop subpartition P_2000_P_LOW;Table altered.

hash分区是不能被删除的

SQL> ALTER TABLE SALES_HASH DROP PARTITION SYS_P81;ALTER TABLE SALES_HASH DROP PARTITION SYS_P81                                      *ERROR at line 1:ORA-14255: table is not partitioned by Range, List, Composite Range or Composite List method

hash分区需要使用COALESCE关键字合并分区

SQL> SELECT TABLE_NAME, PARTITION_NAME,SUBPARTITION_COUNT  FROM DBA_TAB_PARTITIONS WHERE TABLE_NAME = 'SALES_HASH';  2    3  TABLE_NAME                     PARTITION_NAME                      SUBPARTITION_COUNT------------------------------ ------------------------------ ------------------SALES_HASH                     P1                                           0SALES_HASH                     P2                                           0SALES_HASH                     P3                                           0SALES_HASH                     P4                                           0SALES_HASH                     SYS_P81                                              0SQL> ALTER TABLE SALES_HASH COALESCE PARTITION;Table altered.SQL> SELECT TABLE_NAME, PARTITION_NAME,SUBPARTITION_COUNT  FROM DBA_TAB_PARTITIONS WHERE TABLE_NAME = 'SALES_HASH';  2    3  TABLE_NAME                     PARTITION_NAME                      SUBPARTITION_COUNT------------------------------ ------------------------------ ------------------SALES_HASH                     P1                                           0SALES_HASH                     P2                                           0SALES_HASH                     P3                                           0SALES_HASH                     P4                                           0

删除hash子分区用如下语法

ALTER TABLE diving MODIFY PARTITION us_locations     COALESCE SUBPARTITION;

分区交换

exchange partition是用来将分区表与普通表之间做转换。但是普通表只能和分区表中的某个分区做交换。而不能简单的将普通表变成分区表。

CREATE TABLE t(   empno   NUMBER,   sal     NUMBER)PARTITION BY RANGE   (sal)   (      PARTITION sal_less_3000 VALUES LESS THAN (3000),      PARTITION sal_between_3000_5000 VALUES LESS THAN (5000));

生成两个普通表

SQL> create table t_part1 as select empno,sal from emp where sal<3000;Table created.SQL>  create table t_part2 as select empno,sal from emp where sal>=3000 and sal<5000;Table created.

查看表的data_object_id

SQL> COL OBJECT_NAME FOR A30SQL> COL SUBOBJECT_NAME FOR A30SQL> select OBJECT_NAME,SUBOBJECT_NAME,OBJECT_ID,DATA_OBJECT_ID from dba_objects where object_name in ('T','T_PART1','T_PART2');OBJECT_NAME                    SUBOBJECT_NAME                       OBJECT_ID DATA_OBJECT_ID------------------------------ ------------------------------ ---------- --------------T                              SAL_LESS_3000                    88777   88777T                                                                  88776T_PART2                                                       88775   88775T_PART1                                                       88774   88774T                              SAL_BETWEEN_3000_5000            88778   88778

进行分区交换

SQL>  alter table t exchange partition sal_less_3000 with table t_part1;Table altered.SQL> alter table t exchange partition sal_between_3000_5000 with table t_part2;Table altered.SQL> select count(*) from t;  COUNT(*)----------        26

再次查看data_object_id

SQL> select OBJECT_NAME,SUBOBJECT_NAME,OBJECT_ID,DATA_OBJECT_ID from dba_objects where object_name in ('T','T_PART1','T_PART2');OBJECT_NAME                    SUBOBJECT_NAME                       OBJECT_ID DATA_OBJECT_ID------------------------------ ------------------------------ ---------- --------------T                              SAL_LESS_3000                    88777   88774T                                                                  88776T_PART2                                                       88775   88778T_PART1                                                       88774   88777T                              SAL_BETWEEN_3000_5000            88778   88775

可见t_part1、t_part2的data_object_id与分区的值发生了对调。交换分区执行修改了数据字典的内容。效率非常高。

子分区也可以发生交换，请参考官方文档。

分区合并

将两个分区合并成一个分区，hash分区例外

SQL> alter table accounts merge partitions p_northcentral ,p_southcentral into partition p_central;Table altered.

如果是interval分区，可以使用如下语法

ALTER TABLE transactionsMERGE PARTITIONS FOR(TO_DATE('15-JAN-2007','dd-MON-yyyy')), FOR(TO_DATE('16-JAN-2007','dd-MON-yyyy'));

分区拆分

LIST分区

ALTER TABLE sales_by_region    SPLIT PARTITION region_east VALUES ('CT', 'MA', 'MD')    INTO     ( PARTITION region_east_1          TABLESPACE tbs2,      PARTITION region_east_2        STORAGE (INITIAL 8M))    PARALLEL 5;

The literal value list for the original region_east partition was specified as:

PARTITION region_east VALUES ('MA','NY','CT','NH','ME','MD','VA','PA','NJ')

The two new partitions are:

• region_east_1 with a literal value list of ('CT','MA','MD')

• region_east_2 inheriting the remaining literal value list of ('NY','NH','ME','VA','PA','NJ')

范围分区

ALTER TABLE vet_cats SPLIT PARTITION       fee_katy at (100) INTO ( PARTITION      fee_katy1, PARTITION fee_katy2);

假设fee_katy分区的取值为[90-110)，那么新拆分的两个分区的取值为fee_katy1=[90-100),fee_katy2=[100-110) .

时间间隔分区

ALTER TABLE transactions    SPLIT PARTITION FOR(TO_DATE('01-MAY-2007','dd-MON-yyyy'))    AT (TO_DATE('15-MAY-2007','dd-MON-yyyy'));