------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 8 | 1416 | 5 (0)| 00:00:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| TEST | 8 | 1416 | 5 (0)| 00:00:01 |
|* 2 | INDEX RANGE SCAN | TEST_INDEX | 238 | | 1 (0)| 00:00:01 |
------------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("OBJECT_NAME"='STANDARD')
Note
-----
- dynamic sampling used for this statement
从上面的执行计划可以看到当设置隐含参数_USE_NOSEGMENT_INDEXES后，优化器将会使用创建的虚拟索引。在使用虚拟索引需要注意，我们可以分析虚拟索引，但不能重建虚拟索引，如果重建虚拟索引会收到ORA-8114: "User attempted to alter a fake index"错误提示，可以删除虚拟索引。