使用DBMS_REDEFINITION在线切换普通表到分区表
使用导出导入(datapump)方式将普通表切换为分区表
Oracle分区索引(三)
表，非分区键上的主键或唯一索引是否一定是全局索引
SQL> drop index bita_created_date_i;
--下面创建全局索引，创建时需要指定分区键的范围和值
SQL> CREATE INDEX bita_created_date_i
ON big_table (created_date)
GLOBAL PARTITION BY RANGE (created_date)
(
PARTITION
idx_1 VALUES LESS THAN (TO_DATE ('01/01/2013', 'DD/MM/YYYY'))
TABLESPACE idx1,
PARTITION
idx_2 VALUES LESS THAN (TO_DATE ('01/01/2014', 'DD/MM/YYYY'))
TABLESPACE idx2,
PARTITION idx_3 VALUES LESS THAN (maxvalue) TABLESPACE idx3);
SQL> select index_name, partitioning_type, partition_count,locality from user_part_indexes;
INDEX_NAME PARTITI PARTITION_COUNT LOCALI
------------------------------ ------- --------------- ------
BITA_CREATED_DATE_I_G RANGE 3 GLOBAL
SQL> select partition_name, high_value, tablespace_name from user_ind_partitions;
PARTITION_NAME HIGH_VALUE TABLESPACE_NAME
------------------------------ --------------------- ------------------------------
IDX_1 TO_DATE(' 2013-01-01 IDX1
IDX_2 TO_DATE(' 2014-01-01 IDX2
IDX_3 MAXVALUE IDX3
--下面是其执行计划，可以看出支持分区消除
SQL> set autot trace exp;
SQL> select * from big_table where created_date=to_date('20130625','yyyymmdd');
Execution Plan
----------------------------------------------------------
Plan hash value: 1378264218
---------------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | Pstart| Pstop |
---------------------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 41 | 2 (0)| 00:00:01 | | |
| 1 | PARTITION RANGE SINGLE | | 1 | 41 | 2 (0)| 00:00:01 | 2 | 2 |
| 2 | TABLE ACCESS BY GLOBAL INDEX ROWID| BIG_TABLE | 1 | 41 | 2 (0)| 00:00:01 | 2 | 2 |
|* 3 | INDEX RANGE SCAN | BITA_CREATED_DATE_I | 1 | | 1 (0)| 00:00:01 | 2 | 2 |
---------------------------------------------------------------------------------------------------------------------------
--以下为范围查询，Pstart为1，Pstop为2，同样支持分区消除
SQL>
select * from big_table
2 where created_date>=to_date('20120625','yyyymmdd') and created_date<=to_date('20130625','yyyymmdd');
Execution Plan
----------------------------------------------------------
Plan hash value: 213633793
------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | Pstart| Pstop |
------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 3334 | 133K| 14 (0)| 00:00:01 | | |
| 1 | PARTITION RANGE ITERATOR| | 3334 | 133K| 14 (0)| 00:00:01 | 1 | 2 |
|* 2 | TABLE ACCESS FULL | BIG_TABLE | 3334 | 133K| 14 (0)| 00:00:01 | 1 | 2 |
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