- 论坛徽章:
- 0
|
select * from yoyo where id > 200;
Execution Plan
----------------------------------------------------------
Plan hash value: 3535244022
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 14725 | 100K| 7 (0)| 00:00:01 |
|* 1 | TABLE ACCESS FULL| YOYO | 14725 | 100K| 7 (0)| 00:00:01 |
--------------------------------------------------------------------------
SQL> select * from yoyo where id = 200;
Execution Plan
----------------------------------------------------------
Plan hash value: 401148964
--------------------------------------------------------------------------------
----
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time
|
--------------------------------------------------------------------------------
----
| 0 | SELECT STATEMENT | | 2 | 14 | 3 (0)| 00:00:
01 |
| 1 | TABLE ACCESS BY INDEX ROWID| YOYO | 2 | 14 | 3 (0)| 00:00:
01 |
|* 2 | INDEX RANGE SCAN | IDX | 2 | | 1 (0)| 00:00:
01 |
--------------------------------------------------------------------------------
为什么会一个走索引,一个不走呢? |
|