ORACLE-分区表分区字段的update操作

默认情况下，oracle的分区表对于分区字段是不允许进行update操作的，如果有对分区字段行进update，就会报错——ORA-14402: 更新分区关键字列将导致分区的更改。但是可以通过打开表的row movement属性来允许对分区字段的update操作。

例：创建分区表test_part进行实验

create table TEST_PART
(
  A1 NUMBERnot null,
  A2 DATE      not null,
  A3 VARCHAR2(6) not null,
  A4 DATE not null,
  A5 NUMBER not null,
)
partition by range (A1)
(
  partition P1 values less than (1000),
  partition P2 values less than (2000),
  partition P3 values less than (3000),
  partition P4 values less than (4000),
  partition P5 values less than (5000),
  partition P6 values less than (MAXVALUE)
);

插入如下的数据
SQL> select * from test_part;

        A1 A2          A3     A4                  A5
---------- ----------- ------ ----------- ----------
       123 2006-06-30  123456 2006-06-30         123
       456 2006-06-30  asdfgh 2006-06-30         456
         1 2006-06-30  234123 2006-06-30           1
         2 2006-06-30  234234 2006-06-30           2
      1234 2006-06-30  456789 2006-06-30        1234
      1111 2006-06-30  ewrqwe 2006-06-30        1111
      2222 2006-06-30  fdafda 2006-06-30        2222
      3333 2006-06-30  342342 2006-06-30        3333
      5678 2006-06-30  qwerty 2006-06-30        5678

9 rows selected

分区P1、P2的数据分别为：
SQL> select rowid,t.* from test_part partition(p1) t;

ROWID                      A1 A2          A3     A4                  A5
------------------ ---------- ----------- ------ ----------- ----------
AAAGLoAAGAAAtsEAAB        456 2006-06-30  asdfgh 2006-06-30         456
AAAGLoAAGAAAtsEAAC          1 2006-06-30  234123 2006-06-30           1
AAAGLoAAGAAAtsEAAD          2 2006-06-30  234234 2006-06-30           2
AAAGLoAAGAAAtsEAAE        123 2006-06-30  123456 2006-06-30         123

SQL> select rowid,t.* from test_part partition(p2) t;

ROWID                      A1 A2          A3     A4                  A5
------------------ ---------- ----------- ------ ----------- ----------
AAAGLwAAGAAA+8MAAC       1234 2006-06-30  456789 2006-06-30        1234
AAAGLwAAGAAA+8MAAD       1111 2006-06-30  ewrqwe 2006-06-30        1111

直接update提示错误
SQL> update test_part set a1=1123 where a1=123;

update test_part set a1=1123 where a1=123

ORA-14402: 更新分区关键字列将导致分区的更改

打开row movement属性
SQL> alter table test_part enable row movement;

Table altered

再次执行update操作
SQL> update test_part set a1=1123 where a1=123;

1 row updated

执行是成功的并迁移到分区P2上了，且这时候rowid也发生了变化
SQL> select rowid,t.* from test_part partition(p2) t;

ROWID                      A1 A2          A3     A4                  A5
------------------ ---------- ----------- ------ ----------- ----------
AAAGLwAAGAAA+8MAAC       1234 2006-06-30  456789 2006-06-30        1234
AAAGLwAAGAAA+8MAAD       1111 2006-06-30  ewrqwe 2006-06-30        1111
AAAGLwAAGAAA+8PAAB       1123 2006-06-30  123456 2006-06-30         123

SQL>

enable row movement可以允许数据段的压缩、update分区字段的数据（跨分区的）

但是，也是有限制性的：对于普通表（heap-organized）行迁移后rowid会发生变化，对于索引表（index-