alter session set query_rewrite_integrity=enforced
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;