| LEADING | ORDERED | ||
|---|---|---|---|
| {code:sql | titleBGColor=#FFFFFF | title=!http://download.oracle.com/docs/cd/E11882_01/server.112/e17118/img/leading_hint.gif! | borderStyle=solid} SELECT /*+ LEADING(T2) */ * FROM T1, T2 WHERE T1.N4 = T2.N4 AND T1.N2 = 50; |
| Id | Operation | Name | Rows | Bytes | Cost (%CPU) | Time |
| 0 | SELECT STATEMENT | 11 | 308 | 5 (0) | 00:00:01 | |
| 1 | NESTED LOOPS | |||||
| 2 | NESTED LOOPS | 11 | 308 | 5 (0) | 00:00:01 | |
| 3 | TABLE ACCESS FULL | T2 | 11 | 154 | 2 (0) | 00:00:01 |
| INDEX RANGE SCAN | T1N2 | 10 | 1 (0) | 00:00:01 | |
| TABLE ACCESS BY INDEX ROWID | T1 | 1 | 14 | 1 (0) | 00:00:01 |
-- 추천, 조인 순서 만 지정, 방법은 별도 지정 필요 (USE_NL, USE_HASH...)
– http://ukja.tistory.com/166
|{code:sql|titleBGColor=#FFFFFF|title=!http://download.oracle.com/docs/cd/E11882_01/server.112/e17118/img/ordered_hint.gif!|borderStyle=solid}
SELECT /*+ ORDERED */ *
FROM T1, T2
WHERE T1.N4 = T2.N4
AND T1.N2 = 50;
--------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 17 | 476 | 2 (0)| 00:00:01 |
| 1 | NESTED LOOPS | | | | | |
| 2 | NESTED LOOPS | | 17 | 476 | 2 (0)| 00:00:01 |
| 3 | TABLE ACCESS BY INDEX ROWID| T1 | 2 | 28 | 1 (0)| 00:00:01 |
|* 4 | INDEX RANGE SCAN | T1N2 | 10 | | 1 (0)| 00:00:01 |
|* 5 | INDEX RANGE SCAN | T2N4 | 11 | | 1 (0)| 00:00:01 |
| 6 | TABLE ACCESS BY INDEX ROWID | T2 | 11 | 154 | 1 (0)| 00:00:01 |
--------------------------------------------------------------------------------------
-- 비추, 하지만 LEADING 보다 강함
|