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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 );
SQL>
SQL> INSERT INTO EMP VALUES(7369, 'SMITH', 'CLERK', 7902,TO_DATE('17-DEC-1980', 'DD-MON-YYYY'), 800, NULL, 20);
SQL> INSERT INTO EMP VALUES(7499, 'ALLEN', 'SALESMAN', 7698,TO_DATE('20-FEB-1981', 'DD-MON-YYYY'), 1600, 300, 30);
SQL> INSERT INTO EMP VALUES(7521, 'WARD', 'SALESMAN', 7698,TO_DATE('22-FEB-1981', 'DD-MON-YYYY'), 1250, 500, 30);
SQL> INSERT INTO EMP VALUES(7566, 'JONES', 'MANAGER', 7839,TO_DATE('2-APR-1981', 'DD-MON-YYYY'), 2975, NULL, 20);
SQL> INSERT INTO EMP VALUES(7654, 'MARTIN', 'SALESMAN', 7698,TO_DATE('28-SEP-1981', 'DD-MON-YYYY'), 1250, 1400, 30);
SQL> INSERT INTO EMP VALUES(7698, 'BLAKE', 'MANAGER', 7839,TO_DATE('1-MAY-1981', 'DD-MON-YYYY'), 2850, NULL, 30);
SQL> INSERT INTO EMP VALUES(7782, 'CLARK', 'MANAGER', 7839,TO_DATE('9-JUN-1981', 'DD-MON-YYYY'), 2450, NULL, 10);
SQL> INSERT INTO EMP VALUES(7788, 'SCOTT', 'ANALYST', 7566,TO_DATE('09-DEC-1982', 'DD-MON-YYYY'), 3000, NULL, 20);
SQL> INSERT INTO EMP VALUES(7839, 'KING', 'PRESIDENT', NULL,TO_DATE('17-NOV-1981', 'DD-MON-YYYY'), 5000, NULL, 10);
SQL> INSERT INTO EMP VALUES(7844, 'TURNER', 'SALESMAN', 7698,TO_DATE('8-SEP-1981', 'DD-MON-YYYY'), 1500, 0, 30);
SQL> INSERT INTO EMP VALUES(7876, 'ADAMS', 'CLERK', 7788,TO_DATE('12-JAN-1983', 'DD-MON-YYYY'), 1100, NULL, 20);
SQL> INSERT INTO EMP VALUES(7900, 'JAMES', 'CLERK', 7698,TO_DATE('3-DEC-1981', 'DD-MON-YYYY'), 950, NULL, 30);
SQL> INSERT INTO EMP VALUES(7902, 'FORD', 'ANALYST', 7566,TO_DATE('3-DEC-1981', 'DD-MON-YYYY'), 3000, NULL, 20);
SQL> INSERT INTO EMP VALUES(7934, 'MILLER', 'CLERK', 7782,TO_DATE('23-JAN-1982', 'DD-MON-YYYY'), 1300, NULL, 10);
SQL>
SQL> CREATE TABLE DEPT(
2 DEPTNO NUMBER(2),
3 DNAME VARCHAR2(14),
4 LOC VARCHAR2(13)
5 );
SQL>
SQL> INSERT INTO DEPT VALUES (10, 'ACCOUNTING', 'NEW YORK');
SQL> INSERT INTO DEPT VALUES (20, 'RESEARCH', 'DALLAS');
SQL> INSERT INTO DEPT VALUES (30, 'SALES', 'CHICAGO');
SQL> INSERT INTO DEPT VALUES (40, 'OPERATIONS', 'BOSTON');
SQL>
SQL>
SQL>
SQL> alter session set query_rewrite_enabled=true;
SQL>
SQL> alter session set query_rewrite_integrity=enforced;
SQL>
SQL> set autotrace traceonly explain
SQL>
SQL> select dept.deptno, dept.dname, count (*)
2 from emp, dept
3 where emp.deptno = dept.deptno
4 group by dept.deptno, dept.dname
5 /
Execution Plan
----------------------------------------------------------
Plan hash value: 3219813164
------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost |
------------------------------------------------------------
| 0 | SELECT STATEMENT | | 67 | 4690 | 5 |
| 1 | SORT GROUP BY | | 67 | 4690 | 5 |
|* 2 | HASH JOIN | | 67 | 4690 | 3 |
| 3 | TABLE ACCESS FULL| EMP | 82 | 1066 | 1 |
| 4 | TABLE ACCESS FULL| DEPT | 82 | 4674 | 1 |
------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("EMP"."DEPTNO"="DEPT"."DEPTNO")
Note
-----
- cpu costing is off (consider enabling it)
SQL>
SQL>
SQL> select count(*) from emp;
Execution Plan
----------------------------------------------------------
Plan hash value: 2083865914
---------------------------------------------------
| Id | Operation | Name | Rows | Cost |
---------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 1 |
| 1 | SORT AGGREGATE | | 1 | |
| 2 | TABLE ACCESS FULL| EMP | 82 | 1 |
---------------------------------------------------
Note
-----
- cpu costing is off (consider enabling it)
SQL>
SQL> select * from dept where initcap(dname) = 'Sales';
Execution Plan
----------------------------------------------------------
Plan hash value: 3383998547
----------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost |
----------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 39 | 1 |
|* 1 | TABLE ACCESS FULL| DEPT | 1 | 39 | 1 |
----------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter(INITCAP("DNAME")='Sales')
Note
-----
- cpu costing is off (consider enabling it)
SQL>
SQL>
SQL> set autotrace off
SQL>
SQL>
SQL> drop table emp;
SQL>
SQL> drop table dept;
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