Mega Code Archive

Analyze table with primary key and foreign key

SQL> SQL> CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL, 2 ENAME VARCHAR2(10), 3 JOB VARCHAR2(9), 4 MGR NUMBER(4), 5 HIREDATE DATE, 6 SAL NUMBER(7, 2), 7 COMM NUMBER(7, 2), 8 DEPTNO NUMBER(2)); 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 (DEPTNO NUMBER(2),DNAME VARCHAR2(14),LOC VARCHAR2(13) ); 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> analyze table emp compute statistics; Table analyzed. SQL> analyze table dept compute statistics; Table analyzed. SQL> SQL> alter table emp add constraint emp_pk primary key(empno); Table altered. SQL> alter table dept add constraint dept_pk primary key(deptno); Table altered. SQL> alter table emp add constraint emp_fk_dept foreign key (deptno) references dept; Table altered. SQL> SQL> set autotrace traceonly explain SQL> SQL> select * from emp, dept where emp.deptno = dept.deptno; Execution Plan ---------------------------------------------------------- Plan hash value: 3487251775 ---------------------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | ---------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 14 | 700 | 3 (0)| 00:00:01 | | 1 | NESTED LOOPS | | 14 | 700 | 3 (0)| 00:00:01 | | 2 | TABLE ACCESS FULL | EMP | 14 | 448 | 2 (0)| 00:00:01 | | 3 | TABLE ACCESS BY INDEX ROWID| DEPT | 1 | 18 | 1 (0)| 00:00:01 | |* 4 | INDEX UNIQUE SCAN | DEPT_PK | 1 | | 0 (0)| 00:00:01 | ---------------------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 4 - access("EMP"."DEPTNO"="DEPT"."DEPTNO") SQL> SQL> analyze table emp compute statistics; Table analyzed. SQL> analyze table dept compute statistics; Table analyzed. SQL> SQL> select * from emp, dept where emp.deptno = dept.deptno; Execution Plan ---------------------------------------------------------- Plan hash value: 3487251775 ---------------------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | ---------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 14 | 700 | 3 (0)| 00:00:01 | | 1 | NESTED LOOPS | | 14 | 700 | 3 (0)| 00:00:01 | | 2 | TABLE ACCESS FULL | EMP | 14 | 448 | 2 (0)| 00:00:01 | | 3 | TABLE ACCESS BY INDEX ROWID| DEPT | 1 | 18 | 1 (0)| 00:00:01 | |* 4 | INDEX UNIQUE SCAN | DEPT_PK | 1 | | 0 (0)| 00:00:01 | ---------------------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 4 - access("EMP"."DEPTNO"="DEPT"."DEPTNO") SQL> SQL> set autotrace off SQL> SQL> drop table emp cascade constraints; Table dropped. SQL> drop table dept cascade constraints; Table dropped. SQL>