Oracle执行计划之表访问操作(二)
54
------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 2 | 16 | 3 (0)| 00:00:01 |
|* 1 | TABLE ACCESS BY ROWID RANGE| T1 | 2 | 16 | 3 (0)| 00:00:01 |
------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - access("A".ROWID>CHARTOROWID(:A))
PL/SQL procedure successfully completed.
（6）TABLE ACCESS CLUSTER
通过簇来访问表。示例：
[sql]
SQL> exec sql_explain('select * from dept_10 where department_id=:A');
Plan hash value: 2151594128
--------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 133 | 2 (0)| 00:00:01 |
| 1 | TABLE ACCESS CLUSTER| DEPT_10 | 1 | 133 | 2 (0)| 00:00:01 |
|* 2 | INDEX UNIQUE SCAN | IDX_PERSONNEL | 1 | | 1 (0)| 00:00:01 |
--------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("DEPARTMENT_ID"=TO_NUMBER(:A))
Note
-----
- dynamic sampling used for this statement (level=2)
PL/SQL 过程已成功完成。
（7）TABLE ACCESS BY LOCAL INDEX ROWID
通过由本地分区索引获取到ROWID访问表。示例：
[sql]
SQL> exec sql_explain('select * from info where id=1');
Plan hash value: 3053108795
-------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | Pstart| Pstop |
-------------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 11 | 2 (0)| 00:00:01 | | |
| 1 | PARTITION RANGE ALL | | 1 | 11 | 2 (0)| 00:00:01 | 1 | 4 |
| 2 | TABLE ACCESS BY LOCAL INDEX ROWID| INFO | 1 | 11 | 2 (0)| 00:00:01 | 1 | 4 |
|* 3 | INDEX RANGE SCAN | ID_LOCAL_IDX | 1 | | 1 (0)| 00:00:01 | 1 | 4 |
-------------------------------------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
3 - access("ID"=1)
PL/SQL procedure successfully completed.
（8）TABLE ACCESS BY GLOBAL INDEX ROWID
通过全局分区索引获取到ROWID访问表。（全局分区索引也可以建立在非分区表上）示例：
[sql]
SQL> exec sql_explain('select * from info1 where id=1');
Plan hash value: 170147769
--------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | Psta