[置顶] 深入学习分区表及分区索引(5)--创建range-hash组合分区

创建range-hash组合分区

语法如下：图[composite_partitioning.gif]

需要我们指定的有：

l column_list:分区依赖列(支持多个，中间以逗号分隔);

l subpartition:子分区方式，有两处：

n Subpartition_by_list:语法与list分区完全相同，只不过把关键字partition换成subpartition

n Subpartition_by_hash:语法与hash分区完全相同，只不过把关键字partition换成subpartition

l partition:分区名称;

l range_partition_values_clause:与range分区范围值的语法;

l tablespace_clause:分区的存储属性，例如所在表空间等属性(可为空)，默认继承基表所在表空间的属性。

组合分区相对于普通分区，语法上稍稍复杂了一些，但也正因如此，其子分区的创建可以非常灵活，下面分别举几个例子(注：仅示例，并非穷举所有形式)

①　为所有分区各创建4个hash子分区

JSSWEB> create table t_partition_rh (id number,name varchar2(50))

  2  partition by range(id) subpartition by hash(name)

  3  subpartitions 4 store in (tbspart01, tbspart02, tbspart03,tbspart04)(

  4  partition t_r_p1 values less than (10) tablespace tbspart01,

  5  partition t_r_p2 values less than (20) tablespace tbspart02,

  6  partition t_r_p3 values less than (30) tablespace tbspart03,

  7  partition t_r_pd values less than (maxvalue) tablespace tbspart04);

表已创建。

JSSWEB> select partitioning_type,subpartitioning_type,partition_count,def_subpartition_count

  2  From user_part_tables where table_name='T_PARTITION_RH';

PARTITI SUBPART PARTITION_COUNT DEF_SUBPARTITION_COUNT

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

RANGE   HASH                  4                      4

JSSWEB> select partition_name,subpartition_count,high_value

  2  from user_tab_partitions where table_name='T_PARTITION_RH';

PARTITION_NAME  SUBPARTITION_COUNT HIGH_VALUE

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

T_R_P2                           4 20

T_R_P3                           4 30

T_R_PD                           4 MAXVALUE

T_R_P1                           4 10

JSSWEB> select partition_name,subpartition_name,tablespace_name

  2  from user_tab_subpartitions where table_name='T_PARTITION_RH';

PARTITION_NAME  SUBPARTITION_NAME              TABLESPACE_NAME

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

T_R_P2          SYS_SUBP140                    TBSPART02

T_R_P2          SYS_SUBP139                    TBSPART02

T_R_P2          SYS_SUBP138                    TBSPART02

T_R_P2          SYS_SUBP137                    TBSPART02

T_R_P3          SYS_SUBP144                    TBSPART03

T_R_P3          SYS_SUBP143                    TBSPART03

T_R_P3          SYS_SUBP142                    TBSPART03

T_R_P3          SYS_SUBP141                    TBSPART03

T_R_PD          SYS_SUBP148                    TBSPART04

T_R_PD          SYS_SUBP147                    TBSPART04

T_R_PD          SYS_SUBP146                    TBSPART04

T_R_PD          SYS_SUBP145                    TBSPART04

T_R_P1          SYS_SUBP133                    TBSPART01

T_R_P1          SYS_SUBP136                    TBSPART01

T_R_P1          SYS_SUBP135                    TBSPART01

T_R_P1          SYS_SUBP134                    TBSPART01

已选择16行。

这里我们要学到一个新的数据字典：user_tab_subpartitions，用于查询表的子分区信息。

②　对某个分区创建hash子分区

JSSWEB> create table t_partition_rh (id number,name varchar2(50))

  2  partition by range(id) subpartition by hash(name)(

  3  partition t_r_p1 values less than (10) tablespace tbspart01,

  4  partition t_r_p2 values less than (20) tablespace tbspart02,

  5  partition t_r_p3 values less than (30) tablespace tbspart03

  6  (subpartition t_r_p3_h1 tablespace tbspart01,

  7   subpartition t_r_p3_h2 tablespace tbspart02,

  8   subpartition t_r_p3_h3 tablespace tbspart03),

  9  partition t_r_pd values less than (maxvalue) tablespace tbspart04);

表已创建。

JSSWEB> select partitioning_type,subpartitioning_type,partition_count,def_subpartition_count

  2  From user_part_tables where table_name='T_PARTITION_RH';

PARTITI SUBPART PARTITION_COUNT DEF_SUBPARTITION_COUNT

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

RANGE   HASH                  4                      1

JSSWEB> select partition_name,subpartition_count,high_value

  2  from user_tab_partitions where table_name='T_PARTITION_RH';

PARTITION_NAME  SUBPARTITION_COUNT HIGH_VALUE

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

T_R_P1                           1 10

T_R_P2                           1 20

T_R_P3                           3 30

T_R_PD                           1 MAXVALUE

JSSWEB> select partition_name,subpartition_name,tablespace_name

  2  from user_tab_subpartitions where table_name='T_PARTITION_RH';

PARTITION_NAME  SUBPARTITION_NAME              TABLESPACE_NAME

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

T_R_P1          SYS_SUBP149                    TBSPART01

T_R_P2          SYS_SUBP150                    TBSPART02

T_R_P3          T_R_P3_H3                      TBSPART03

T_R_P3          T_R_P3_H2                      TBSPART02

T_R_P3          T_R_P3_H1                      TBSPART01

T_R_PD          SYS_SUBP151                    TBSPART04

已选择6行。

当然，还可以给各个分区指定不同的子分区

JSSWEB> create table t_partition_rh (id number,name varchar2(50))

  2  partition by range(id) subpartition by hash(name)(

  3  partition t_r_p1 values less than (10) tablespace tbspart01,

  4  partition t_r_p2 values less than (20) tablespace tbspart02

  5  (subpartition t_r_p2_h1 tablespace tbspart01,

  6   subpartition t_r_p2_h2 tablespace tbspart02),

  7  partition t_r_p3 values less than (30) tablespace tbspart03

  8   subpartitions 3 store in (tbspart01,tbspart02,tbspart03),

  9  partition t_r_pd values less than (maxvalue) tablespace tbspart04

 10  (subpartition t_r_p3_h1 tablespace tbspart01,

 11   subpartition t_r_p3_h2 tablespace tbspart02,

 12   subpartition t_r_p3_h3 tablespace tbspart03)

 13  );

表已创建。

JSSWEB> select partitioning_type,subpartitioning_type,partition_count,def_subpartition_count

  2  From user_part_tables where table_name='T_PARTITION_RH';

PARTITI SUBPART PARTITION_COUNT DEF_SUBPARTITION_COUNT

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

RANGE   HASH                  4                      1

JSSWEB> select partition_name,subpartition_count,high_value

  2  from user_tab_partitions where table_name='T_PARTITION_RH';

PARTITION_NAME  SUBPARTITION_COUNT HIGH_VALUE