Oracle非分区索引，全局分区索引和本地分区索引。

Posted 2022-07-30 alex-zeng

1.如果按照索引是否分区作为划分依据，Oracle 的索引类型可以分为非分区索引，全局分区索引和本地分区索引。

2.创建演示实例

--创建非分区表
create table test_partition_01(
number_1 number,
number_2 number,
string_1 varchar2(10),
string_2 varchar2(20)
);
-- 写入数据
insert into test_partition_01(number_1,
                              number_2,
                              string_1,
                              string_2)
select dbms_random.random() as number_1,
       round(dbms_random.value(0, 100000)) as number_2,
       dbms_random.string(opt => ‘A‘, len => 1) as String_1,
       dbms_random.string(opt => ‘p‘, len => 10) as String_2
  from dual
connect by rownum < 100000;
commit;

--试图创建本地分区索引 报错
CREATE INDEX ix_test_partition_01_1 ON test_partition_01(number_1) 
local (PARTITION p1,
       PARTITION p2,
       PARTITION p3);---ORA-14016
---创建普通索引       
CREATE INDEX ix_test_partition_01_1 ON test_partition_01(number_1);
--创建 全局分区索引 
CREATE INDEX ix_test_partition_01_2 ON test_partition_01(number_2)
   GLOBAL PARTITION BY RANGE (number_2)
      (PARTITION p1 VALUES LESS THAN (10000),
       PARTITION p2 VALUES LESS THAN (55000),
       PARTITION p3 VALUES LESS THAN (MAXVALUE));
结论：非分区表可以创建普通索引和全局分区索引不能创建本地分区索引。
-------------------------------------------------------------------------------
create table test_partiton_02(
number_1 number,
number_2 number,
string_1 varchar2(10),
string_2 varchar2(20)
) partition by range(number_2)
(
partition p1 values less than (10000),
partition p2 values less than (20000),
partition p3 values less than (50000),
partition p4 values less than (70000),
partition p5 values less than (maxvalue)
);
--试图创建本地分区索引
CREATE INDEX ix_test_partiton_02_1 ON test_partiton_02(number_1) 
local (PARTITION p1,
       PARTITION p2,
       PARTITION p3);--ora-14024 索引的分区数必须等于基础表的分区数
--创建本地分区索引
CREATE INDEX ix_test_partiton_02_1 ON test_partiton_02(number_1) 
local (PARTITION p1,
       PARTITION p2,
       PARTITION p3,
       PARTITION p4,
       PARTITION p5
       );--drop index ix_test_partiton_02_1;
CREATE INDEX ix_test_partiton_02_1 ON test_partiton_02(number_1) local; --和上面的创建方式等效

--drop index ix_test_partiton_02_1;
CREATE INDEX ix_test_partiton_02_1 ON test_partiton_02(number_1) ; --默认创建的是 非分区索引，分区索引才分 全局索引还是本地索引 ;
---创建全局分区索引
CREATE INDEX ix_test_partiton_02_2 ON test_partiton_02(number_2)
   GLOBAL PARTITION BY RANGE (number_2)
      (PARTITION p1 VALUES LESS THAN (10000),
       PARTITION p2 VALUES LESS THAN (55000),
       PARTITION p3 VALUES LESS THAN (MAXVALUE));
---写入测试数据
insert into test_partiton_02(number_1,
                              number_2,
                              string_1,
                              string_2)
select dbms_random.random() as number_1,
       round(dbms_random.value(0, 100000)) as number_2,
       dbms_random.string(opt => ‘A‘, len => 1) as String_1,
       dbms_random.string(opt => ‘p‘, len => 10) as String_2
  from dual
connect by rownum < 100001;
commit;
--分析表
analyze table test_partiton_02 compute statistics;

--查看 普通索引是否可用 
select * from user_indexes t where t.INDEX_NAME in(‘IX_TEST_PARTITON_02_1‘,‘IX_TEST_PARTITON_02_2‘,‘IX_TEST_PARTITON_02_3‘);

---查看分区索引是否 可用
select * from user_ind_partitions t where t.INDEX_NAME in(‘IX_TEST_PARTITON_02_1‘,‘IX_TEST_PARTITON_02_2‘,‘IX_TEST_PARTITON_02_3‘);

---改变分区，查看普通索引和分区索引是否可用

-- 必须调整最后一个分区的大小，所以如果最后一个分区指定了最大值 必须先删除，再添加
alter table test_partiton_02 add partition p6 values less than (90000);

alter table test_partiton_02 drop partition p5;

--- 结论 改变分区 普通索引和全局分区索引都会失效 只有本地分区索引好使

PS：最好用以下语句查看索引的定义语句
select dbms_metadata.get_ddl(object_type => ‘INDEX‘,
                             name        => ‘IX_TEST_PARTITON_02_1‘)
  FROM DUAL;
        
select dbms_metadata.get_ddl(object_type => ‘INDEX‘,
                             name        => ‘IX_TEST_PARTITON_02_2‘)
  FROM DUAL;
 --- 发现了 plsql developer Version 11.0.5.1790  (64 bit) 的一个 bug  在用View 查看 DDL时 没有反应真实的情况