1 create table t_partition(a int,b int)
2 partition by range(a)
3 (partition p1 values less than (10),
4 partition p2 values less than (maxvalue)
5* )
13:36:09 SQL> /

Table created.

Elapsed: 00:00:00.24

Elapsed: 00:00:00.02
13:36:27 SQL> insert into t_partition values(null,1);

1 row created.

Elapsed: 00:00:00.01
13:36:33 SQL> insert into t_partition values(1,1);

1 row created.

Elapsed: 00:00:00.00
13:36:40 SQL> insert into t_partition values(12,1);

1 row created.

Elapsed: 00:00:00.00
13:36:43 SQL> commit;

Commit complete.

Elapsed: 00:00:00.00
13:36:45 SQL> select * from t_partition;

         A          B
---------- ----------
         1          1
                    1
        12          1

Elapsed: 00:00:00.01
13:36:49 SQL> select table_name,partition_name,num_rows from user_tab_partitions
where table_name='T_PARTITION';

TABLE_NAME                     PARTITION_NAME                   NUM_ROWS
------------------------------ ------------------------------ ----------
T_PARTITION                    P1
T_PARTITION                    P2

Elapsed: 00:00:00.26

Elapsed: 00:00:00.13
13:37:52 SQL> exec dbms_stats.gather_table_stats(user,'t_partition');

PL/SQL procedure successfully completed.

Elapsed: 00:00:03.33
13:38:03 SQL> select table_name,partition_name,num_rows from user_tab_partitions
where table_name='T_PARTITION';

TABLE_NAME                     PARTITION_NAME                   NUM_ROWS
------------------------------ ------------------------------ ----------
T_PARTITION                    P1                                      1
T_PARTITION                    P2                                      2

Elapsed: 00:00:00.05
13:38:06 SQL> select * from t_partition partition(p1);

A B
---------- ----------
1 1

Elapsed: 00:00:00.04
13:38:37 SQL> select * from t_partition partition(p2);

         A          B
---------- ----------
                    1
        12          1

Elapsed: 00:00:00.00
13:38:40 SQL>

小结:分区键为空,此行记录归属于最后一个发区

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oracle partition分区_分区列为空测试(一)

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