쿼리 변환 - 조인 제거

SQL> CREATE TABLE t1 (
  2    id NUMBER NOT NULL,
  3    n NUMBER,
  4    pad VARCHAR2(4000),
  5    CONSTRAINT t1_pk PRIMARY KEY(id)
  6  )
  7  PCTFREE 99 PCTUSED 1;
00:00:00.03
SQL>
SQL> CREATE TABLE t2 (
  2    id NUMBER NOT NULL,
  3    t1_id NUMBER NOT NULL,
  4    n NUMBER,
  5    pad VARCHAR2(4000),
  6    CONSTRAINT t2_pk PRIMARY KEY(id),
  7    CONSTRAINT t2_t1_fk FOREIGN KEY (t1_id) REFERENCES t1
  8  )
  9  PCTFREE 99 PCTUSED 1;
SQL>
SQL> CREATE VIEW v AS
  2  SELECT t1.id AS t1_id, t1.n AS t1_n, t2.id AS t2_id, t2.n AS t2_n
  3  FROM t1, t2
  4  WHERE t1.id = t2.t1_id;
경   과: 00:00:00.01
SQL>
SQL> EXPLAIN PLAN FOR SELECT t2_id, t2_n FROM v;
경   과: 00:00:00.06
SQL>
SQL> SELECT * FROM table(dbms_xplan.display);

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


---------------------------------------------------------------
| Id  | Operation         | Name | Rows  | Bytes | Cost (%CPU)|
---------------------------------------------------------------
|   0 | SELECT STATEMENT  |      |   100 |   800 |    30   (0)|
|   1 |  TABLE ACCESS FULL| T2   |   100 |   800 |    30   (0)|
---------------------------------------------------------------

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