쿼리 변환 - OUTER 조인을 INNER 조인으로

SQL> EXPLAIN PLAN FOR
  2  SELECT *
  3  FROM t1, t2
  4  WHERE t1.id = t2.t1_id(+)
  5  AND t2.id IS NOT NULL;

SQL>
SQL> SELECT * FROM table(dbms_xplan.display);

PLAN_TABLE_OUTPUT
---------------------------------------------------------------------------------


----------------------------------------------------------------
| Id  | Operation          | Name | Rows  | Bytes | Cost (%CPU)|
----------------------------------------------------------------
|   0 | SELECT STATEMENT   |      |   100 | 11900 |    36   (3)|
|*  1 |  HASH JOIN         |      |   100 | 11900 |    36   (3)|
|   2 |   TABLE ACCESS FULL| T1   |    10 |   570 |     5   (0)|
|   3 |   TABLE ACCESS FULL| T2   |   100 |  6200 |    30   (0)|
----------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - access("T1"."ID"="T2"."T1_ID")

Note
-----
   - 'PLAN_TABLE' is old version

SQL> EXPLAIN PLAN FOR
  2  SELECT /*+ no_outer_join_to_inner */ *
  3  FROM t1, t2
  4  WHERE t1.id = t2.t1_id(+)
  5  AND t2.id IS NOT NULL;

SQL>
SQL> SELECT * FROM table(dbms_xplan.display);

PLAN_TABLE_OUTPUT
-------------------------------------------------------------------------


-----------------------------------------------------------------
| Id  | Operation           | Name | Rows  | Bytes | Cost (%CPU)|
-----------------------------------------------------------------
|   0 | SELECT STATEMENT    |      |   100 | 11900 |    36   (3)|
|*  1 |  FILTER             |      |       |       |            |
|*  2 |   HASH JOIN OUTER   |      |   100 | 11900 |    36   (3)|
|   3 |    TABLE ACCESS FULL| T1   |    10 |   570 |     5   (0)|
|   4 |    TABLE ACCESS FULL| T2   |   100 |  6200 |    30   (0)|
-----------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter("T2"."ID" IS NOT NULL)
   2 - access("T1"."ID"="T2"."T1_ID"(+))

Note
-----
   - 'PLAN_TABLE' is old version