Oracle 史上最详细的分区表详解

一、分区表的概念

分区表：当表中的数据量不断增大，查询数据的速度就会变慢，应用程序的性能就会下降，这时就应该考虑对表进行分区。表进行分区后，逻辑上表仍然是一张完整的表，只是将表中的数据在物理上存放到多个“表空间”(物理文件上)，这样查询数据时，不至于每次都扫描整张表而只是从当前的分区查到所要的数据大大提高了数据查询的速度。"""分区表的具体作用"""Oracle的表分区功能通过改善可管理性、性能和可用性，从而为各式应用程序带来了极大的好处。通常，分区可以使某些查询以及维护操作的性能大大提高。此外,分区还可以极大简化常见的管理任务，分区是构建千兆字节数据系统或超高可用性系统的关键工具。 分区功能能够将表、索引或索引组织表进一步细分为段，这些数据库对象的段叫做分区。每个分区有自己的名称，还可以选择自己的存储特性。从数据库管理员的角度来看，一个分区后的对象具有多个段，这些段既可进行集体管理，也可单独管理，这就使数据库管理员在管理分区后的对象时有相当大的灵活性。但是，从应用程序的角度来看，分区后的表与非分区表完全相同，使用 SQL DML 命令访问分区后的表时，无需任何修改。"""分区表使用场景"""1、表的大小超过2GB。
2、表中包含历史数据，新的数据被增加到新的分区中。"""分区表的优缺点"""优点：
1、改善查询性能：对分区对象的查询可以仅搜索自己关心的分区，提高检索速度。
2、增强可用性：如果表的某个分区出现故障，表在其他分区的数据仍然可用；
3、维护方便：如果表的某个分区出现故障，需要修复数据，只修复该分区即可；
4、均衡I/O：可以把不同的分区映射到不同磁盘以平衡I/O，改善整个系统性能。缺点：
分区表相关：已经存在的表没有方法可以直接转化为分区表。不过 Oracle 提供了在线重定义表的功能。

二、分区表相关视图

显示分区表信息
DBA_PART_TABLES显示表分区信息 显示数据库所有分区表的详细分区信息﹕DBA_TAB_PARTITIONS显示子分区信息 显示数据库所有组合分区表的子分区信息﹕DBA_TAB_SUBPARTITIONS显示分区列 显示数据库所有分区表的分区列信息﹕DBA_PART_KEY_COLUMNS显示子分区列 显示数据库所有分区表的子分区列信息﹕DBA_SUBPART_KEY_COLUMNS

三、分区表分类

1、范围分区表
2、列表分区表
3、哈希分区表
4、引用分区表
5、组合分区表

1、RANGE分区表

说明：针对记录字段的值在某个范围。
规则：
（1）、每一个分区都必须有一个VALUES LESS THEN子句，它指定了一个不包括在该分区中的上限值。
分区键的任何值等于或者大于这个上限值的记录都会被加入到下一个高一些的分区中。
（2）、所有分区，除了第一个，都会有一个隐式的下限值，这个值就是此分区的前一个分区的上限值。
（3）、在最高的分区中，MAXVALUE被定义。MAXVALUE代表了一个不确定的值。这个值高于其它分区中的任何分区键的值，
也可以理解为高于任何分区中指定的VALUE LESS THEN的值，同时包括空值。若不添加maxvalue的分区插入数值一旦超过设置的最大上限会报错。分区表分区处于同一表空间"""使用时间列来做分区列"""create table part_range_t1(
id number,
name varchar2(20),
birthday date)
partition by range(birthday)(partition p1 values less than(to_date('2001-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS')),partition p2 values less than(to_date('2002-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS')),partition p3 values less than(to_date('2003-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS'))
)
/SCOTT@TNS_PDB01>select table_owner,table_name,partition_name,tablespace_name from dba_tab_partitions where table_name = 'PART_RANGE_T1';TABLE_OWNE TABLE_NAME      PARTITION_ TABLESPACE
---------- --------------- ---------- ----------
SCOTT      PART_RANGE_T1   P1         USERS
SCOTT      PART_RANGE_T1   P2         USERS
SCOTT      PART_RANGE_T1   P3         USERSSCOTT@TNS_PDB01>select * from dba_part_key_columns where name = 'PART_RANGE_T1';OWNER    NAME        OBJEC COLUMN_NAM COLUMN_POSITION COLLATED_COLUMN_ID
---------- --------------- ----- ---------- --------------- ------------------
SCOTT      PART_RANGE_T1   TABLE BIRTHDAY         1SCOTT@TNS_PDB01>select table_name,partitioning_type from dba_part_tables where table_name = 'PART_RANGE_T1';TABLE_NAME               PARTITION
------------------------------ ---------
PART_RANGE_T1              RANGE"""使用数字列做为分区列"""create table p_t3(
n number,
name varchar2(20))
partition by range(n)(
partition p1 values less than(1000),
partition p2 values less than(10000),
partition p3 values less than(maxvalue))分区表分区处于不同表空间create table part_range_t3(
id number,
name varchar2(20),
birthday date)
partition by range(birthday)(
partition p1 values less than(to_date('2001-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS')) tablespace tbs1,
partition p2 values less than(to_date('2010-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS')) tablespace tbs2,
partition p3 values less than(maxvalue) tablespace users)
/SCOTT@TNS_PDB01>select table_name,partition_name,tablespace_name from dba_tab_partitions where table_name = 'PART_RANGE_T3';TABLE_NAME             PARTITION_ TABLESPACE
------------------------------ ---------- ----------
PART_RANGE_T3              P1     TBS1
PART_RANGE_T3              P2     TBS2
PART_RANGE_T3              P3     USERSSCOTT@TNS_PDB01>select * from dba_part_key_columns where name = 'PART_RANGE_T3';OWNER    NAME        OBJEC COLUMN_NAM COLUMN_POSITION COLLATED_COLUMN_ID
---------- --------------- ----- ---------- --------------- ------------------
SCOTT      PART_RANGE_T3   TABLE BIRTHDAY         1SCOTT@TNS_PDB01>select table_name,partitioning_type from dba_part_tables where table_name = 'PART_RANGE_T3';TABLE_NAME               PARTITION
------------------------------ ---------
PART_RANGE_T3              RANGE

2、LIST分区表

说明：该分区的特点是某列的值只有有限个值，基于这样的特点我们可以采用列表分区。
规则：默认分区为DEFAULT，若不添加DEFAULT的分区插入数值不属于所设置的分区会报错。
在定义范围分区时，每个分区定义必须使用 values（'value01','value02'....）子句。表示该分区存储包含相关value值的数据行。
在定义范围分区时，最后一个分区可以是values（DEFAULT）。表示该分区存储未在其他分区定义的数据行。create table part_list_t1(
id number,
name varchar2(20),
sex char(1))
partition by list(sex)(
partition male values('M') tablespace tbs1,
partition female values('F') tablespace tbs2)SCOTT@TNS_PDB01>select table_owner,table_name,partition_name,tablespace_name from dba_tab_partitions where table_name = 'PART_LIST_T1';TABLE_OWNE TABLE_NAME            PARTITION_ TABLESPACE
---------- ------------------------------ ---------- ----------
SCOTT      PART_LIST_T1           FEMALE     TBS2
SCOTT      PART_LIST_T1           MALE       TBS1SCOTT@TNS_PDB01>select table_name,partitioning_type from dba_part_tables where table_name = 'PART_LIST_T1';TABLE_NAME              PARTITION
------------------------------ ---------
PART_LIST_T1               LISTSCOTT@TNS_PDB01>select * from dba_part_key_columns where name = 'PART_LIST_T1';OWNER     NAME        OBJEC COLUMN_NAM COLUMN_POSITION COLLATED_COLUMN_ID
---------- --------------- ----- ---------- --------------- ------------------
SCOTT      PART_LIST_T1    TABLE SEX              1create table part_list_t2(
id number,
name varchar2(20),
age number)
partition by list(age)(
partition p1 values(10) tablespace tbs1,
partition p2 values(20) tablespace tbs2,
partition p3 values(default) tablespace users)
/default --存储age列上除了10、20外的其他值指定多个值
create table part_list_t2(
id number,
name varchar2(20),
age int)
partition by list(age)(
partition age_10_20 values(10,20),
partition age_30 values(30),
partition age_40_50 values(40,50),
partition age_default values(default))
/SCOTT@TNS_PDB01>select table_name,partition_name,tablespace_name,high_value from dba_tab_partitions where table_name = 'PART_LIST_T2';TABLE_NAME               PARTITION_NAME             TABLESPACE HIGH_VALUE
------------------------------ ------------------------------ ---------- ------------------------------
PART_LIST_T2               AGE_10_20              USERS  10, 20
PART_LIST_T2               AGE_30                 USERS  30
PART_LIST_T2               AGE_40_50              USERS  40, 50
PART_LIST_T2               AGE_DEFAULT            USERS  default

3、HASH 散列分区表

说明：这类分区是在列值上使用散列算法，以确定将行放入哪个分区中。
规则：当列的值没有合适的条件，没有范围的规律，也没有固定的值，建议使用散列分区。
散列分区为通过指定分区编号来均匀分布数据的一种分区类型，因为通过在I/O设备上进行散列分区，
使得这些分区大小一致。建议分区的数量采用2的n次方，这样可以使得各个分区间数据分布更加均匀。Example:
创建hash分区有两种方法：一种方法是指定分区的名字，另一种方法是指定分区数量。例一、常规方法指定分区名字create table part_hash_t1(id number,name varchar2(20),age int)
partition by hash(age)(
partition p1 tablespace tbs1,
partition p2 tablespace tbs2)
/例二、指定分区数量create table part_hash_t2(id number,name varchar2(20),age int)
partition by hash(age) partitions 2 store in(tbs1,tbs2)
/SCOTT@TNS_PDB01>select table_name,partition_name,tablespace_name from dba_tab_partitions where table_name = 'PART_HASH_T2';TABLE_NAME              PARTITION_ TABLESPACE
------------------------------ ---------- ----------
PART_HASH_T2               SYS_P388   TBS1
PART_HASH_T2               SYS_P389   TBS2SCOTT@TNS_PDB01>select table_name,partitioning_type from dba_part_tables where table_name = 'PART_HASH_T2';TABLE_NAME             PARTITION
------------------------------ ---------
PART_HASH_T2               HASHSCOTT@TNS_PDB01>select * from dba_part_key_columns where name = 'PART_HASH_T2';OWNER     NAME        OBJEC COLUMN_NAM COLUMN_POSITION COLLATED_COLUMN_ID
---------- --------------- ----- ---------- --------------- ------------------
SCOTT      PART_HASH_T2    TABLE AGE              1--往往我们不需要知道bash分区的名字，因为数据放在哪个分区是oracle根据bash算法存放的，并不是用户指定，
所以当用户插入一条记录，并不能确定放在哪个分区，这个不同于range和list

4、引用分区表

如果父表是分区表，子表想要按照父表的方式进行分区。
父表中被引用的主键列不一定要是分区键。父表：
create table part_range_t4(
id number primary key,
name varchar2(20),
time date,
age int)
partition by range(time)(
partition p1 values less than(to_date('2001-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS')),
partition p2 values less than(to_date('2010-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS')),
partition p3 values less than(maxvalue))
/子表:
create table part_ref_t4(
pid number,
id number not null,
constraint fk_t4 foreign key(id) references part_range_t4(id))
partition by reference(fk_t4);Table created.SCOTT@TNS_PDB01>select table_name,partition_name from dba_tab_partitions where table_name = 'PART_REF_T4';TABLE_NAME            PARTITION_
------------------------------ ----------
PART_REF_T4            P1
PART_REF_T4            P2
PART_REF_T4            P3SCOTT@TNS_PDB01>select * from dba_part_key_columns where name = 'PART_REF_T4';OWNER    NAME        OBJEC COLUMN_NAM COLUMN_POSITION COLLATED_COLUMN_ID
---------- --------------- ----- ---------- --------------- -----------
SCOTT      PART_REF_T4     TABLE ID           1SCOTT@TNS_PDB01>select table_name,partitioning_type from dba_part_tables where table_name = 'PART_REF_T4';TABLE_NAME             PARTITION
------------------------------ ---------
PART_REF_T4            REFERENCE

5、组合分区表

组合分区中，主要通过在不同列上，使用“范围分区”、“列表分区”以及“HASH分区”不同组合方式，进而实现组合分区。
组合分区中，分区本身没有相应的segment，可以认为是一个逻辑容器，只有子分区拥有实际的segment，用于存放数据。
在11g以后，组合分区新增了四种组合方式：“RANGE-RANGE”、“LIST-RANGE”、“LIST-HASH”以及“LIST-LIST”。Example:
以LIST-LIST的组合方式为例，创建组合分区CREATE TABLE "EMPLOYEE_LIST_LIST_PART"
( "EMPNO" NUMBER(4,0),
"ENAME" VARCHAR2(10),
"JOB" VARCHAR2(9),
"MGR" NUMBER(4,0),
"HIREDATE" DATE,
"SAL" NUMBER(7,2),
"COMM" NUMBER(7,2),
"DEPTNO" NUMBER(2,0)
)
PARTITION BY LIST (DEPTNO) --LIST-LIST的组合方式,先分区DEPTNO再分区JOB
SUBPARTITION BY LIST (JOB)
(
PARTITION EMPLOYEE_DEPTNO_10 VALUES (10) TABLESPACE test_tbs_01
( SUBPARTITION EMPLOYEE_10_JOB_MAGAGER VALUES ('MANAGER'),
SUBPARTITION EMPLOYEE_10_JOB_DEFAULT VALUES (DEFAULT)
),
PARTITION EMPLOYEE_DEPTNO_20 VALUES (20) TABLESPACE test_tbs_02
( SUBPARTITION EMPLOYEE_20_JOB_MAGAGER VALUES ('MANAGER'),
SUBPARTITION EMPLOYEE_20_JOB_DEFAULT VALUES (DEFAULT)
),
PARTITION EMPLOYEE_DEPTNO_OTHERS VALUES (DEFAULT) TABLESPACE test_tbs_03
( SUBPARTITION EMPLOYEE_30_JOB_MAGAGER VALUES ('MANAGER'),
SUBPARTITION EMPLOYEE_30_JOB_DEFAULT VALUES (DEFAULT)
)
);create table t1(
id number,
name varchar2(10))
partition by list(id)
subpartition by list(name)(
partition p_id_1 values(10) tablespace pdb01_tbs01
(subpartition p_id_1_name1 values('aaa'),
subpartition p_id_1_name2 values(default)),
partition p_id_2 values(20) tablespace pdb01_tbs02
(
subpartition p_id_2_name1 values('aaa'),
subpartition p_id_2_name2 values(default)))create table part_list_list_t1(
empno number,
ename varchar2(20),
job varchar2(20),
sal number,
deptno number)
partition by list(deptno)
subpartition by list(job)(
partition deptno_10 values(10) tablespace tbs1(
subpartition deptno_10_job_manager values('MANAGER'),
subpartition deptno_10_job_default values(default)),
partition deptno_20 values(20) tablespace tbs2(
subpartition deptno_20_job_manager values('MANAGER'),
subpartition deptno_20_job_default values(default)),
partition deptno_default values(default) tablespace users(
subpartition dept_default_job_manager values('MANAGER'),
subpartition dept_default_job_default values(default)))
/SCOTT@TNS_PDB01>select table_name,partition_name,subpartition_name from dba_tab_subpartitions where table_name = 'PART_LIST_LIST_T1';TABLE_NAME            PARTITION_NAME             SUBPARTITION_NAME
------------------------------ ------------------------------ ---------
PART_LIST_LIST_T1          DEPTNO_DEFAULT             DEPT_DEFAULT_JOB_MANAGER
PART_LIST_LIST_T1          DEPTNO_DEFAULT             DEPT_DEFAULT_JOB_DEFAULT
PART_LIST_LIST_T1          DEPTNO_10              DEPTNO_10_JOB_MANAGER
PART_LIST_LIST_T1          DEPTNO_10              DEPTNO_10_JOB_DEFAULT
PART_LIST_LIST_T1          DEPTNO_20              DEPTNO_20_JOB_MANAGER
PART_LIST_LIST_T1          DEPTNO_20              DEPTNO_20_JOB_DEFAULTSCOTT@TNS_PDB01>select table_name,partitioning_type,subpartitioning_type from dba_part_tables where table_name = 'PART_LIST_LIST_T1';TABLE_NAME              PARTITION SUBPARTIT
------------------------------ --------- ---------
PART_LIST_LIST_T1          LIST  LIST

四、分区表管理

1、增加分区

增加RANGE分区
ALTER TABLE range_example ADD PARTITION part04 VALUES LESS THAN (TO_DATE('2008-10-1 00:00:00','yyyy-mm-dd hh24:mi:ss'));create table part_range_t1(
id number,
name varchar2(20),
birthday date)
partition by range(birthday)(
partition p1 values less than(to_date('2001-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS')),
partition p2 values less than(to_date('2010-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS')),
partition p_maxvalue values less than(maxvalue))
/SCOTT@TNS_PDB01>select table_name,partition_name,tablespace_name from dba_tab_partitions where table_name = 'PART_RANGE_T1' and table_owner = 'SCOTT';TABLE_NAME            PARTITION_NAME             TABLESPACE
------------------------------ ------------------------------ ---------
PART_RANGE_T1              P1                 USERS
PART_RANGE_T1              P2                 USERS
PART_RANGE_T1              P_MAXVALUE             USERSSCOTT@TNS_PDB01>alter table part_range_t1 add partition p3 values less than(to_date('2014-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS'));
alter table part_range_t1 add partition p3 values less than(to_date('2014-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS'))增加的分区必须比最后一个分区更高级*
ERROR at line 1:
ORA-14074: partition bound must collate higher than that of the last partitionSCOTT@TNS_PDB01>select table_name,partition_name,tablespace_name from dba_tab_partitions where table_name = 'PART_RANGE_T1' and table_owner = 'SCOTT';TABLE_NAME               PARTITION_NAME             TABLESPACE
------------------------------ ------------------------------ ---------
PART_RANGE_T1              P1                 USERS
PART_RANGE_T1              P2                 USERS
PART_RANGE_T1              P_MAXVALUE             USERS删除分区
SCOTT@TNS_PDB01>alter table part_range_t1 drop partition p_maxvalue;Table altered.SCOTT@TNS_PDB01>alter table part_range_t1 add partition p3 values less than(to_date('2014-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS'));Table altered.SCOTT@TNS_PDB01>select table_name,partition_name,tablespace_name from dba_tab_partitions where table_name = 'PART_RANGE_T1' and table_owner = 'SCOTT';TABLE_NAME             PARTITION_NAME             TABLESPACE
------------------------------ ------------------------------ ---------
PART_RANGE_T1              P1                 USERS
PART_RANGE_T1              P2                 USERS
PART_RANGE_T1              P3                 USERSSCOTT@TNS_PDB01>alter table part_range_t1 add partition p_maxvalue values less than(maxvalue);Table altered.SCOTT@TNS_PDB01>select table_name,partition_name,tablespace_name from dba_tab_partitions where table_name = 'PART_RANGE_T1' and table_owner = 'SCOTT';TABLE_NAME              PARTITION_NAME             TABLESPACE
------------------------------ ------------------------------ ---------
PART_RANGE_T1              P1                 USERS
PART_RANGE_T1              P2                 USERS
PART_RANGE_T1              P3                 USERS
PART_RANGE_T1              P_MAXVALUE             USERS增加List分区create table part_list_t1(
id number,
name varchar2(20),
age int)
partition by list(age)(
partition age_10 values(10) tablespace tbs1,
partition age_20 values(20) tablespace tbs2,
partition age_default values(default) tablespace users)
/SCOTT@TNS_PDB01>alter table part_list_t1 add partition age_30 values(30);
alter table part_list_t1 add partition age_30 values(30)*
ERROR at line 1:
ORA-14323: cannot add partition when DEFAULT partition existsSCOTT@TNS_PDB01>alter table part_list_t1 drop partition age_default;Table altered.SCOTT@TNS_PDB01>select table_name,partition_name from dba_tab_partitions where table_name = 'PART_LIST_T1';TABLE_NAME            PARTITION_NAME
------------------------------ ------------------------------
PART_LIST_T1               AGE_10
PART_LIST_T1               AGE_20SCOTT@TNS_PDB01>alter table part_list_t1 add partition age_30 values(30);Table altered.SCOTT@TNS_PDB01>select table_name,partition_name from dba_tab_partitions where table_name = 'PART_LIST_T1';TABLE_NAME               PARTITION_NAME
------------------------------ ------------------------------
PART_LIST_T1               AGE_10
PART_LIST_T1               AGE_20
PART_LIST_T1               AGE_30SCOTT@TNS_PDB01>alter table part_list_t1 add partition age_default values(default);Table altered.SCOTT@TNS_PDB01>select table_name,partition_name from dba_tab_partitions where table_name = 'PART_LIST_T1';TABLE_NAME             PARTITION_NAME
------------------------------ ------------------------------
PART_LIST_T1               AGE_10
PART_LIST_T1               AGE_20
PART_LIST_T1               AGE_30
PART_LIST_T1               AGE_DEFAULTSCOTT@TNS_PDB01>alter table part_list_t1 modify partition age_20 add values(40);Table altered.SCOTT@TNS_PDB01>alter table part_list_t1 modify partition age_20 drop values(20);Table altered.LIST分区增加多个值
SCOTT@TNS_PDB01>alter table part_list_t1 modify partition age_20 add values(20,50,60);Table altered.SCOTT@TNS_PDB01>insert into part_list_t1 values(1,'xiao zhang',50);1 row created.SCOTT@TNS_PDB01>insert into part_list_t1 values(2,'xiao long',100);1 row created.SCOTT@TNS_PDB01>insert into part_list_t1 values(3,'lissen',20);1 row created.SCOTT@TNS_PDB01>insert into part_list_t1 values(4,'xiao hong',13);1 row created.SCOTT@TNS_PDB01>commit;Commit complete.SCOTT@TNS_PDB01>select * from part_list_t1;ID NAME           AGE
--- --------------- ----------1 xiao zhang          503 lissen          202 xiao long          1004 xiao hong           13SCOTT@TNS_PDB01>select table_name,partition_name,high_value from dba_tab_partitions where table_name = 'PART_LIST_T1';TABLE_NAME              PARTITION_NAME             HIGH_VALUE
------------------------------ ------------------------------ ------------------------------
PART_LIST_T1               AGE_10                 10
PART_LIST_T1               AGE_20                 40, 20, 50, 60
PART_LIST_T1               AGE_30                 30
PART_LIST_T1               AGE_DEFAULT            default--Adding Values for a List Partition
ALTER TABLE list_example MODIFY PARTITION part04 ADD VALUES('MIS');
--Dropping Values from a List Partition
ALTER TABLE list_example MODIFY PARTITION part04 DROP VALUES('MIS');
--hash partitioned table增加HASH分区create table part_hash_t1(
id number,
name varchar2(20),
age int)
partition by hash(age)(
partition age_1,
partition age_2)
/SCOTT@TNS_PDB01>alter table part_hash_t1 add partition age_3;Table altered.ALTER TABLE hash_example ADD PARTITION part03;
--hash partitioned table 新增partition时，现有表的中所有data都有重新计算hash值，然后重新分配到分区中。
--所以被重新分配的分区的 indexes需要rebuild增加子分区create table part_composit_t1(
empno number,
ename varchar2(20),
job varchar2(20),
deptno number)
partition by list(deptno)
subpartition by list(job)(
partition dept_10 values(10) tablespace tbs1(
subpartition dept_10_job_manager values('MANAGER'),
subpartition dept_10_job_salesman values('SALESMAN')),
partition dept_20 values(20) tablespace tbs2(
subpartition dept_20_job_manager values('MANAGER'),
subpartition dept_20_job_salesman values('SALESMAN')))
/SCOTT@TNS_PDB01>select table_name,partition_name,subpartition_name from dba_tab_subpartitions where table_name = 'PART_COMPOSIT_T1';TABLE_NAME             PARTITION_NAME             SUBPARTITION_NAME
------------------------------ ------------------------------ ------------------------------
PART_COMPOSIT_T1           DEPT_10                DEPT_10_JOB_MANAGER
PART_COMPOSIT_T1           DEPT_10                DEPT_10_JOB_SALESMAN
PART_COMPOSIT_T1           DEPT_20                DEPT_20_JOB_MANAGER
PART_COMPOSIT_T1           DEPT_20                DEPT_20_JOB_SALESMANSCOTT@TNS_PDB01>alter table part_composit_t1 modify partition dept_20 add subpartition dept_20_job_analyst values('ANALYST');Table altered.SCOTT@TNS_PDB01>select table_name,partition_name,subpartition_name from dba_tab_subpartitions where table_name = 'PART_COMPOSIT_T1';TABLE_NAME               PARTITION_NAME             SUBPARTITION_NAME
------------------------------ ------------------------------ ------------------------------
PART_COMPOSIT_T1           DEPT_10                DEPT_10_JOB_MANAGER
PART_COMPOSIT_T1           DEPT_10                DEPT_10_JOB_SALESMAN
PART_COMPOSIT_T1           DEPT_20                DEPT_20_JOB_MANAGER
PART_COMPOSIT_T1           DEPT_20                DEPT_20_JOB_SALESMAN
PART_COMPOSIT_T1           DEPT_20                DEPT_20_JOB_ANALYSTALTER TABLE range_hash_example MODIFY PARTITION part_1 ADD SUBPARTITION part_1_sub_4; --注意复合分区这里是MODIFY

2、删除分区

对range分区表删除分区
ALTER TABLE PART_TAB_SALE_RANGE_LIST DROP PARTITION P3; 对range分区表list子分区删除子分区
ALTER TABLE PART_TAB_SALE_RANGE_LIST DROP SUBPARTITION P4SUB1;对于哈希分区表,哈希复合分区表,range-hash分区表
-- 减少hash 分区的个数，一次减少一个。不能指定减少partition的名称。
ALTER TABLE hash_example COALESCE PARTITION ;SCOTT@TNS_PDB01>select table_name,partition_name from dba_tab_partitions where table_name = 'PART_HASH_T1';TABLE_NAME              PARTITION_NAME
------------------------------ ------------------------------
PART_HASH_T1               AGE_1
PART_HASH_T1               AGE_2
PART_HASH_T1               AGE_3SCOTT@TNS_PDB01>alter table part_hash_t1 coalesce partition;Table altered.SCOTT@TNS_PDB01>select table_name,partition_name from dba_tab_partitions where table_name = 'PART_HASH_T1';TABLE_NAME             PARTITION_NAME
------------------------------ ------------------------------
PART_HASH_T1               AGE_1
PART_HASH_T1               AGE_2SCOTT@TNS_PDB01>alter table part_hash_t1 coalesce partition;Table altered.SCOTT@TNS_PDB01>select table_name,partition_name from dba_tab_partitions where table_name = 'PART_HASH_T1';TABLE_NAME             PARTITION_NAME
------------------------------ ------------------------------
PART_HASH_T1               AGE_1--subpartition 的语法对于如下
ALTER TABLE diving MODIFY PARTITION us_locations
COALESCE SUBPARTITION;SCOTT@TNS_PDB01>alter table part_composit_t1 drop partition dept_20;Table altered.SCOTT@TNS_PDB01>select table_name,partition_name,subpartition_name from dba_tab_subpartitions where table_name = 'PART_COMPOSIT_T1';TABLE_NAME              PARTITION_NAME             SUBPARTITION_NAME
------------------------------ ------------------------------ ------------------------------
PART_COMPOSIT_T1           DEPT_10                DEPT_10_JOB_MANAGER
PART_COMPOSIT_T1           DEPT_10                DEPT_10_JOB_SALESMANSCOTT@TNS_PDB01>alter table part_composit_t1 drop subpartition dept_10_job_salesman;Table altered.SCOTT@TNS_PDB01>select table_name,partition_name,subpartition_name from dba_tab_subpartitions where table_name = 'PART_COMPOSIT_T1';TABLE_NAME              PARTITION_NAME             SUBPARTITION_NAME
------------------------------ ------------------------------ ------------------------------
PART_COMPOSIT_T1           DEPT_10                DEPT_10_JOB_MANAGER

3、合并分区

ALTER TABLE range_example
MERGE PARTITIONS part01_1,part01_2 INTO PARTITION part01
UPDATE INDEXES;
如果省略update indexes子句的话，必须重建受影响的分区的index 。
ALTER TABLE range_example MODIFY PARTITION part02 REBUILD UNUSABLE LOCAL INDEXES;SCOTT@TNS_PDB01>select table_name,partition_name,high_value from dba_tab_partitions where table_name = 'PART_LIST_T1';TABLE_NAME               PARTITION_NAME             HIGH_VALUE
------------------------------ ------------------------------ ---------
PART_LIST_T1               AGE_10                 10
PART_LIST_T1               AGE_20                 40, 20, 50, 60
PART_LIST_T1               AGE_30                 30
PART_LIST_T1               AGE_DEFAULT            defaultSCOTT@TNS_PDB01>alter table part_list_t1 merge partitions age_10,age_20 into partition age_10_20 [update indexes];Table altered.SCOTT@TNS_PDB01>select table_name,partition_name,high_value from dba_tab_partitions where table_name = 'PART_LIST_T1';TABLE_NAME               PARTITION_NAME             HIGH_VALUE
------------------------------ ------------------------------ ---------PART_LIST_T1            AGE_10_20              10, 40, 20, 50, 60
PART_LIST_T1               AGE_30                 30
PART_LIST_T1               AGE_DEFAULT            defaultSCOTT@TNS_PDB01>alter table part_list_t1 modify partition age_10_20 rebuild unusable local indexes;
Table altered.

4、分割分区

1）、range类型分区的分割

ALTER TABLE range_example
SPLIT PARTITION part01
AT (TO_DATE('2008-06-01 00:00:00','yyyy-mm-dd hh24:mi:ss'))
INTO ( PARTITION part01_1,PARTITION part01_2
);
一个分区一次性只能分割成两个分区，at关键字后面指定的值为第一个分区的range范围，默认为less than 。SCOTT@TNS_PDB01>select table_name,partition_name,high_value from dba_tab_partitions where table_name = 'PART_RANGE_T1';TABLE_NAME            PARTITION_NAME             HIGH_VALUE
------------------------------ ------------------------------ ------------------------------
PART_RANGE_T1              P1                 TO_DATE(' 2001-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')PART_RANGE_T1              P2                 TO_DATE(' 2010-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')PART_RANGE_T1              P3                 TO_DATE(' 2014-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')PART_RANGE_T1              P_MAXVALUE             MAXVALUESCOTT@TNS_PDB01>alter table part_range_t1 split partition p2 at(to_date('2005-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS')) into (partition p2_1,partition p2_2);Table altered.SCOTT@TNS_PDB01>select table_name,partition_name,high_value from dba_tab_partitions where table_name = 'PART_RANGE_T1';TABLE_NAME              PARTITION_NAME             HIGH_VALUE
------------------------------ ------------------------------ ------------------------------
PART_RANGE_T1              P1                 TO_DATE(' 2001-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')PART_RANGE_T1              P2_1               TO_DATE(' 2005-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')PART_RANGE_T1              P2_2               TO_DATE(' 2010-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')PART_RANGE_T1              P3                 TO_DATE(' 2014-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')PART_RANGE_T1              P_MAXVALUE             MAXVALUE

2）、list类型分区的分割

ALTER TABLE list_example
SPLIT PARTITION part01 VALUES('ME','PE')
INTO ( PARTITION part01_1, PARTITION part01_2
);SCOTT@TNS_PDB01>select table_name,partition_name,high_value from dba_tab_partitions where table_name = 'PART_LIST_T2';TABLE_NAME              PARTITION_NAME             HIGH_VALUE
------------------------------ ------------------------------ ------------------------------
PART_LIST_T2               AGE_10_20              10, 20
PART_LIST_T2               AGE_30                 30
PART_LIST_T2               AGE_40_50              40, 50
PART_LIST_T2               AGE_DEFAULT            defaultvalues后指定的是分区后的第一个分区的LIST值SCOTT@TNS_PDB01>alter table part_list_t2 split partition age_10_20 values(10) into (partition age_10,partition age_20);Table altered.SCOTT@TNS_PDB01>select table_name,partition_name,high_value from dba_tab_partitions where table_name = 'PART_LIST_T2';TABLE_NAME            PARTITION_NAME             HIGH_VALUE
------------------------------ ------------------------------ ------------------------------
PART_LIST_T2               AGE_10                 10
PART_LIST_T2               AGE_20                 20
PART_LIST_T2               AGE_30                 30
PART_LIST_T2               AGE_40_50              40, 50
PART_LIST_T2               AGE_DEFAULT            default

3）、Range_Hash类型分区的分割

新分区会对原有分区的subpartition做rehash的动作。如果在分割是指定subpartition的个数，则按新规则rehash subpartition，如果没有指定则保留原有subpartition的个数不变。ALTER TABLE range_hash_example SPLIT PARTITION part_1
AT (TO_DATE('2008-07-01 00:00:00','yyyy-mm-dd hh24:mi:ss')) INTO (
PARTITION part_1_1 SUBPARTITIONS 2 STORE IN (tbs01,tbs02),
PARTITION part_1_2
);
subpartitions 2 -- 指定新分区的subpartition的个数，store in 子句指定subpartition存储的tablespaceSCOTT@TNS_PDB01>insert into part_hash_t3 values(1,'xiao zhang',10);1 row created.SCOTT@TNS_PDB01>insert into part_hash_t3 values(2,'xiao wang',20);1 row created.SCOTT@TNS_PDB01>insert into part_hash_t3 values(3,'xiao long',30);1 row created.SCOTT@TNS_PDB01>insert into part_hash_t3 values(4,'xiao xin',40);1 row created.SCOTT@TNS_PDB01>commit;Commit complete.SCOTT@TNS_PDB01>select * from part_hash_t3 order by id;ID NAME        AGE
--- --------------- ----------1 xiao zhang          102 xiao wang           203 xiao long           304 xiao xin            40SCOTT@TNS_PDB01>select table_name,partition_name,high_value from dba_tab_partitions where table_name = 'PART_HASH_T3';TABLE_NAME              PARTITION_NAME             HIGH_VALUE
------------------------------ ------------------------------ ------------------------------
PART_HASH_T3               AGE_1
PART_HASH_T3               AGE_2查询分区数据
SCOTT@TNS_PDB01>select * from part_hash_t3 partition(age_1);ID NAME        AGE
--- --------------- ----------2 xiao wang           203 xiao long           304 xiao xin            40SCOTT@TNS_PDB01>select * from part_hash_t3 partition(age_2);ID NAME          AGE
--- --------------- ----------1 xiao zhang          10"""重命名分区"""alter table part_range_t1 rename partition p2_1 to p2;

五、分区索引

"""普通索引"""
SCOTT@TNS_PDB01>create index idx_part_range_t1_birthday on part_range_t1(birthday);Index created."""本地索引"""
SCOTT@TNS_PDB01>create index idx_part_range_t1_birthday_local on part_range_t1(birthday) local;Index created."""全局索引"""
SCOTT@TNS_PDB01>create index idx_global_part_range_t1_id on part_range_t1(id)2  global partition by range(id)(3  partition part_id_1 values less than(1000),4  partition part_id_max values less than(maxvalue));Index created.

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