Oracle學習之性能優化(十二)分區表
一、分區概念
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Oracle允許將表、索引、索引組織表細分成更小的片，每個片我們稱之為分區。分區有其自己的名字和存儲參數。
如下圖：
每行數據只能屬于一個分區，分區鍵決定數據行屬于哪個分區。分區鍵由一個或多個列組成。Oracle自動的將數據的DML操作映射到相應的分區中。
何時使用分區表：
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.
何時使用分區索引：
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.
分區的優點：
分區裁剪，DML操作的數據如果可以定位到某個或者某些分區，那么只需對這部分數據進行讀寫。
分區智能join，如果關聯查詢只需用到部分分區，那么避免了全表數據的掃描。
易于維護數據。
分區策略：
LIST、RANGE、HASH、SYSTEM、INTERVAL、reference、虛擬列分區。
表分區類型：
單級別分區
組合分區
索引分區類型：
本地分區
全局分區
全局索引
二、創建分區
創建LIST分區
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>插入數據
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;
查詢分區中的數據
SQL> select count(*) from accounts; COUNT(*) ---------- 29 SQL> select count(*) from accounts partition(p_northwest); COUNT(*) ---------- 16 SQL> select count(*) from accounts PARTITION (p_southwest); COUNT(*) ---------- 13 SQL> select count(*) from accounts PARTITION (p_northeast); COUNT(*) ---------- 0
分區裁剪測試
SQL> set autotrace on SQL> select count(*) from accounts where REGION='AZ'; COUNT(*) ---------- 5 Execution 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 | ---------------------------------------------------------------------------------------------------
由執行計劃中可以看出，Oracle只查詢了一個分區的數據。
創建RANGE分區
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新增了一個時間間隔分區，本質上是RANGE分區的一個擴展。
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'))
);時間間隔分區會自動根據數據維護分區。我們做如下數據插入
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;現在我們查看sales2的分區情況
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_2003 SALES2 SYS_P41 SALES2 SYS_P42 SALES2 SYS_P43
可見系統根據數據的實際情況，給我們新建了3個分區，分區由系統自命名。
創建HASH分區
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 );
根據s_productionid的值，算出hash值，將對于的數據行插入到相應的分區中。各分區數據要想分別均勻，分區的個數為2的次方數。
創建SYSTEM分區
此分區與其他的都不同，數據插入到哪個分區與數據本身無關，完全有用戶自定義。
CREATE TABLE t_system ( id NUMBER, name VARCHAR2 (30) ) PARTITION BY SYSTEM (PARTITION p1, PARTITION p2, PARTITION p3, PARTITION p4);
此時往表中直接插入數據就會報錯
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
插入數據，必須指定分區名稱
SQL> insert into t_system partition(p1)(id,name)values(1,'kevin'); 1 row created.
并且重復數據可以插入到不同的分區
SQL> insert into t_system partition(p2)(id,name)values(1,'kevin'); 1 row created.
創建虛擬列分區
Oracle11g新增了虛擬列功能，虛擬列的值從其他的列推導而來，Oracle只保存源數據，這個列不占存儲空間。虛擬列其中一個引申功能就是虛擬列分區功能。11g增加對虛擬列的支持，這使得分區功能更加靈活。如：表中有一個日期列，希望根據日期列進行分區，每個月份一個分區，總共12個分區，不管是哪一年的，只要是那個月，就放在那個月的分區中。
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));
創建參考列分區
子表的分區依賴于父表，我們看如下例子
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'))
);訂單表，按order_date做范圍分區。
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);
訂單項目表，該表分區參考主表。
查看order_items的分區信息
SQL> SELECT TABLE_NAME, PARTITION_NAME FROM DBA_TAB_PARTITIONS WHERE TABLE_NAME = 'ORDER_ITEMS'; TABLE_NAME PARTITION_NAME ------------------------------ ------------------------------ ORDER_ITEMS Q1_2005 ORDER_ITEMS Q2_2005 ORDER_ITEMS Q3_2005 ORDER_ITEMS Q4_2005
對于range和hash分區，你可以指定多列作為分區鍵。列數最多16個。
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-2000 INSERT INTO sales_demo VALUES(2000,12,12, 1000); REM 17-MAR-2001 INSERT INTO sales_demo VALUES(2001,3,17, 2000); REM 1-NOV-2001 INSERT INTO sales_demo VALUES(2001,11,1, 5000); REM 1-JAN-2002 INSERT INTO sales_demo VALUES(2002,1,1, 4000);
組合分區有如下六種：
RANGE-RANGE、RANGE-LIST、RANGE-HASH、LIST-RANGE、LIST-LIST、LIST-HASH 。
組合分區的創建與單分區類似。
創建RANGE-RANGE組合分區
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)
)
);查看分區信息
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 3 SHIPMENTS P_2006_AUG 3 SHIPMENTS P_2006_SEP 3 SHIPMENTS P_2006_OCT 3 SHIPMENTS P_2006_NOV 3 SHIPMENTS P_2006_DEC 3 6 rows selected.
查看子分區信息
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_E SHIPMENTS P_2006_DEC P06_DEC_A SHIPMENTS P_2006_DEC P06_DEC_L SHIPMENTS P_2006_NOV P06_NOV_E SHIPMENTS P_2006_NOV P06_NOV_A SHIPMENTS P_2006_NOV P06_NOV_L SHIPMENTS P_2006_OCT P06_OCT_E SHIPMENTS P_2006_OCT P06_OCT_A SHIPMENTS P_2006_OCT P06_OCT_L SHIPMENTS P_2006_SEP P06_SEP_E SHIPMENTS P_2006_SEP P06_SEP_A TABLE_NAME PARTITION_NAME SUBPARTITION_NAME ------------------------------ ------------------------------ ------------------------------ SHIPMENTS P_2006_SEP P06_SEP_L SHIPMENTS P_2006_AUG P06_AUG_E SHIPMENTS P_2006_AUG P06_AUG_A SHIPMENTS P_2006_AUG P06_AUG_L SHIPMENTS P_2006_JUL P06_JUL_E SHIPMENTS P_2006_JUL P06_JUL_A SHIPMENTS P_2006_JUL P06_JUL_L 18 rows selected.
創建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')
)
);創建RANGE-HASH分區
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'))
);子分區也可以指定模板
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'))
);創建分區索引
本地索引
SQL> create index idx_accounts_number on accounts(account_number) local; Index created.
創建索引時，添加local關鍵字，即為表的每個分區單獨創建一個索引。
SQL> select index_name,partition_name from dba_ind_partitions where index_name='IDX_ACCOUNTS_NUMBER'; INDEX_NAME PARTITION_NAME ------------------------------ ------------------------------ IDX_ACCOUNTS_NUMBER P_NORTHCENTRAL IDX_ACCOUNTS_NUMBER P_NORTHEAST IDX_ACCOUNTS_NUMBER P_NORTHWEST IDX_ACCOUNTS_NUMBER P_SOUTHCENTRAL IDX_ACCOUNTS_NUMBER P_SOUTHEAST IDX_ACCOUNTS_NUMBER P_SOUTHWEST 6 rows selected.
可見，表有幾個分區，就創建幾個索引分區。
全局索引
創建方法與普通索引一致。
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
索引沒有分區。
全局分區索引
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_P61 IDX_ACCOUNTS_CUSTOMER_ID SYS_P62 IDX_ACCOUNTS_CUSTOMER_ID SYS_P63 IDX_ACCOUNTS_CUSTOMER_ID SYS_P64
三、維護分區
添加分區
LIST分區
SQL> ALTER TABLE accounts
ADD PARTITION p_nonmainland VALUES ('HI', 'PR');
Table altered.
SQL>RANGE分區
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分區
SQL> ALTER TABLE sales_hash ADD PARTITION; Table altered.
對于組合分區
SQL> ALTER TABLE shipments
ADD PARTITION p_2007_jan
VALUES LESS THAN (TO_DATE('01-FEB-2007','dd-MON-yyyy'));
Table altered.如果添加分區時，不指定子分區，那么系統默認幫你建立一個子分區
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
添加分區時，也可以指定子分區
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.此時子分區信息如下
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_E SHIPMENTS P_2008_JAN P07_JAN_A SHIPMENTS P_2008_JAN P07_JAN_L
如果組合分區的子分區指定了模板，那么添加分區時，無需指定子分區。
SQL> ALTER TABLE SALES_RANGE_RANGE
ADD PARTITION P_2000
VALUES LESS THAN (TO_DATE ('01-JAN-2001', 'dd-MON-yyyy'));
Table altered.查看分區信息
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_LOW SALES_RANGE_RANGE P_2000 P_2000_P_MEDIUM SALES_RANGE_RANGE P_2000 P_2000_P_HIGH SALES_RANGE_RANGE P_2000 P_2000_P_ULTIMATE
刪除分區
Use one of the following statements to drop a table partition or subpartition:
ALTERTABLE...DROPPARTITIONto drop a table partitionALTERTABLE...DROPSUBPARTITIONto drop a subpartition of a composite *-[range | list] partitioned table
SQL> ALTER TABLE SALES DROP PARTITION SALE_Q1_2004; Table altered.
刪除子分區
SQL> alter table sales_range_range drop subpartition P_2000_P_LOW; Table altered.
hash分區是不能
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