SQL> select /*+ use_concat */ * from hao2 where object_id=1 or object_id=2 or object_id=3;
执行计划
----------------------------------------------------------
Plan hash value: 2739802529
----------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 3 | 282 | 5 (0)| 00:00:01 |
| 1 | INLIST ITERATOR | | | | | |
| 2 | TABLE ACCESS BY INDEX ROWID| HAO2 | 3 | 282 | 5 (0)| 00:00:01 |
|* 3 | INDEX RANGE SCAN | HAO2IND | 3 | | 4 (0)| 00:00:01 |
----------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
3 - access("OBJECT_ID"=1 OR "OBJECT_ID"=2 OR "OBJECT_ID"=3)
统计信息
----------------------------------------------------------
0 recursive calls
0 db block gets
9 consistent gets
0 physical reads
0 redo size
1249 bytes sent via SQL*Net to client
338 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
2 rows processed
SQL> alter session set events '10157 trace name context forever';
会话已更改。
SQL> select /*+ use_concat */ * from hao2 where object_id=1 or object_id=2 or object_id=3;
执行计划
----------------------------------------------------------
Plan hash value: 1202901203
----------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 3 | 282 | 6 (0)| 00:00:01 |
| 1 | CONCATENATION | | | | | |
| 2 | TABLE ACCESS BY INDEX ROWID| HAO2 | 1 | 94 | 2 (0)| 00:00:01 |
|* 3 | INDEX RANGE SCAN | HAO2IND | 1 | | 1 (0)| 00:00:01 |
| 4 | TABLE ACCESS BY INDEX ROWID| HAO2 | 1 | 94 | 2 (0)| 00:00:01 |
|* 5 | INDEX RANGE SCAN | HAO2IND | 1 | | 1 (0)| 00:00:01 |
| 6 | TABLE ACCESS BY INDEX ROWID| HAO2 | 1 | 94 | 2 (0)| 00:00:01 |
|* 7 | INDEX RANGE SCAN | HAO2IND | 1 | | 1 (0)| 00:00:01 |
----------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
3 - access("OBJECT_ID"=1)
5 - access("OBJECT_ID"=3)
7 - access("OBJECT_ID"=2)
统计信息
----------------------------------------------------------
0 recursive calls
0 db block gets
9 consistent gets
0 physical reads
0 redo size
1249 bytes sent via SQL*Net to client
338 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
2 rows processed