analyze and autotrace table with primary key
SQL> CREATE TABLE EMP(
2 EMPNO NUMBER(4) NOT NULL,
3 ENAME VARCHAR2(10),
4 JOB VARCHAR2(9),
5 MGR NUMBER(4),
6 HIREDATE DATE,
7 SAL NUMBER(7, 2),
8 COMM NUMBER(7, 2),
9 DEPTNO NUMBER(2)
10 );
Table created.
SQL>
SQL> INSERT INTO EMP VALUES(7369, 'SMITH', 'CLERK', 7902,TO_DATE('17-DEC-1980', 'DD-MON-YYYY'), 800, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES(7499, 'ALLEN', 'SALESMAN', 7698,TO_DATE('20-FEB-1981', 'DD-MON-YYYY'), 1600, 300, 30);
1 row created.
SQL> INSERT INTO EMP VALUES(7521, 'WARD', 'SALESMAN', 7698,TO_DATE('22-FEB-1981', 'DD-MON-YYYY'), 1250, 500, 30);
1 row created.
SQL> INSERT INTO EMP VALUES(7566, 'JONES', 'MANAGER', 7839,TO_DATE('2-APR-1981', 'DD-MON-YYYY'), 2975, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES(7654, 'MARTIN', 'SALESMAN', 7698,TO_DATE('28-SEP-1981', 'DD-MON-YYYY'), 1250, 1400, 30);
1 row created.
SQL> INSERT INTO EMP VALUES(7698, 'BLAKE', 'MANAGER', 7839,TO_DATE('1-MAY-1981', 'DD-MON-YYYY'), 2850, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES(7782, 'CLARK', 'MANAGER', 7839,TO_DATE('9-JUN-1981', 'DD-MON-YYYY'), 2450, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES(7788, 'SCOTT', 'ANALYST', 7566,TO_DATE('09-DEC-1982', 'DD-MON-YYYY'), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES(7839, 'KING', 'PRESIDENT', NULL,TO_DATE('17-NOV-1981', 'DD-MON-YYYY'), 5000, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES(7844, 'TURNER', 'SALESMAN', 7698,TO_DATE('8-SEP-1981', 'DD-MON-YYYY'), 1500, 0, 30);
1 row created.
SQL> INSERT INTO EMP VALUES(7876, 'ADAMS', 'CLERK', 7788,TO_DATE('12-JAN-1983', 'DD-MON-YYYY'), 1100, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES(7900, 'JAMES', 'CLERK', 7698,TO_DATE('3-DEC-1981', 'DD-MON-YYYY'), 950, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES(7902, 'FORD', 'ANALYST', 7566,TO_DATE('3-DEC-1981', 'DD-MON-YYYY'), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES(7934, 'MILLER', 'CLERK', 7782,TO_DATE('23-JAN-1982', 'DD-MON-YYYY'), 1300, NULL, 10);
1 row created.
SQL>
SQL> CREATE TABLE DEPT(
2 DEPTNO NUMBER(2),
3 DNAME VARCHAR2(14),
4 LOC VARCHAR2(13)
5 );
Table created.
SQL>
SQL> INSERT INTO DEPT VALUES (10, 'ACCOUNTING', 'NEW YORK');
1 row created.
SQL> INSERT INTO DEPT VALUES (20, 'RESEARCH', 'DALLAS');
1 row created.
SQL> INSERT INTO DEPT VALUES (30, 'SALES', 'CHICAGO');
1 row created.
SQL> INSERT INTO DEPT VALUES (40, 'OPERATIONS', 'BOSTON');
1 row created.
SQL>
SQL>
SQL> update emp
2 set deptno = 9
3 where deptno = 10;
3 rows updated.
SQL>
SQL>
SQL> alter table emp add constraint emp_pk primary key(empno);
Table altered.
SQL>
SQL> alter table dept add constraint dept_pk primary key(deptno);
Table altered.
SQL>
SQL> analyze table emp compute statistics;
Table analyzed.
SQL>
SQL> analyze table dept compute statistics;
Table analyzed.
SQL>
SQL> set autotrace on explain
SQL>
SQL> select empno, ename, dept.deptno, dname
2 from emp, dept
3 where emp.deptno(+) = dept.deptno
4 UNION ALL
5 select empno, ename, emp.deptno, null
6 from emp, dept
7 where emp.deptno = dept.deptno(+)
8 and dept.deptno is null
9 order by 1, 2, 3, 4
10 /
EMPNO ENAME DEPTNO DNAME
---------- ---------- ---------- --------------
7369 SMITH 20 RESEARCH
7499 ALLEN 30 SALES
7521 WARD SALES
7566 JONES 20 RESEARCH
7654 MARTIN 30 SALES
7698 BLAKE SALES
7782 CLARK 9
EMPNO ENAME DEPTNO DNAME
---------- ---------- ---------- --------------
7788 SCOTT 20 RESEARCH
7839 KING 9
7844 TURNER 30 SALES
7876 ADAMS 20 RESEARCH
7900 JAMES 30 SALES
EMPNO ENAME DEPTNO DNAME
---------- ---------- ---------- --------------
7902 FORD 20 RESEARCH
7934 MILLER 9
10 ACCOUNTING
40 OPERATIONS
16 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 1556511399
-----------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost |
-----------------------------------------------------------------
| 0 | SELECT STATEMENT | | 28 | 1666 | 7 |
| 1 | SORT ORDER BY | | 28 | 1666 | 4 |
| 2 | UNION-ALL | | | | |
|* 3 | HASH JOIN OUTER | | 14 | 784 | 3 |
| 4 | TABLE ACCESS FULL | DEPT | 4 | 92 | 1 |
| 5 | TABLE ACCESS FULL | EMP | 14 | 462 | 1 |
|* 6 | FILTER | | | | |
| 7 | NESTED LOOPS OUTER| | 14 | 882 | 1 |
| 8 | TABLE ACCESS FULL| EMP | 14 | 560 | 1 |
|* 9 | INDEX UNIQUE SCAN| DEPT_PK | 1 | 23 | |
-----------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
3 - access("EMP"."DEPTNO"(+)="DEPT"."DEPTNO")
6 - filter("DEPT"."DEPTNO" IS NULL)
9 - access("EMP"."DEPTNO"="DEPT"."DEPTNO"(+))
Note
-----
- cpu costing is off (consider enabling it)
SQL>
SQL> select empno, ename, nvl(dept.deptno,emp.deptno), dname
2 from emp FULL OUTER JOIN dept on ( emp.deptno = dept.deptno )
3 order by 1, 2, 3, 4
4 /
EMPNO ENAME NVL(DEPT.DEPTNO,EMP.DEPTNO) DNAME
---------- ---------- --------------------------- --------------
7369 SMITH 20 RESEARCH
7499 ALLEN 30 SALES
7521 WARD 30 SALES
7566 JONES 20 RESEARCH
7654 MARTIN 30 SALES
7698 BLAKE 30 SALES
7782 CLARK 9
7788 SCOTT 20 RESEARCH
7839 KING 9
7844 TURNER 30 SALES
7876 ADAMS 20 RESEARCH
EMPNO ENAME NVL(DEPT.DEPTNO,EMP.DEPTNO) DNAME
---------- ---------- --------------------------- --------------
7900 JAMES 30 SALES
7902 FORD 20 RESEARCH
7934 MILLER 9
10 ACCOUNTING
40 OPERATIONS
16 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 1591132751
--------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost |
--------------------------------------------------------------
| 0 | SELECT STATEMENT | | 15 | 825 | 7 |
| 1 | SORT ORDER BY | | 15 | 825 | 7 |
| 2 | VIEW | | 15 | 825 | 4 |
| 3 | UNION-ALL | | | | |
|* 4 | HASH JOIN OUTER | | 14 | 882 | 3 |
| 5 | TABLE ACCESS FULL| EMP | 14 | 560 | 1 |
| 6 | TABLE ACCESS FULL| DEPT | 4 | 92 | 1 |
|* 7 | FILTER | | | | |
| 8 | TABLE ACCESS FULL| DEPT | 1 | 23 | 1 |
|* 9 | TABLE ACCESS FULL| EMP | 5 | 65 | 1 |
--------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
4 - access("EMP"."DEPTNO"="DEPT"."DEPTNO"(+))
7 - filter( NOT EXISTS (SELECT /*+ UNNEST */ 0 FROM "EMP" "EMP"
WHERE "EMP"."DEPTNO"=:B1))
9 - filter("EMP"."DEPTNO"=:B1)
Note
-----
- cpu costing is off (consider enabling it)
SQL>
SQL> set autotrace off
SQL>
SQL> drop table emp;
Table dropped.
SQL> drop table dept;
Table dropped.