SQL> select * from employee SAMPLE(30); EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO---------- ---------- --------- ---------- --------- ---------- ---------- ---------- 7369 SMITH CLERK 7902 17-DEC-80 800 20 7788 SCOTT ANALYST 7566 19-APR-87 3000 20 7839 KING PRESIDENT 17-NOV-81 5000 10Execution Plan---------------------------------------------------------- 0 SELECT STATEMENT Optimizer=CHOOSE (Cost=2 Card=25 Bytes=2175) 1 0 TABLE access (SAMPLE) OF 'EMPLOYEE' (Cost=2 Card=25 Bytes=2175)Statistics---------------------------------------------------------- 0 recursive calls 0 db block gets 5 consistent gets 0 physical reads 0 redo size 880 bytes sent via SQL*Net to client 503 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 3 rows processedSQL> select * from employee SAMPLE(20); EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO---------- ---------- --------- ---------- --------- ---------- ---------- ---------- 7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30 7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30Execution Plan---------------------------------------------------------- 0 SELECT STATEMENT Optimizer=CHOOSE (Cost=2 Card=16 Bytes=1392) 1 0 TABLE ACCESS (SAMPLE) OF 'EMPLOYEE' (Cost=2 Card=16 Bytes=1392)Statistics---------------------------------------------------------- 0 recursive calls 0 db block gets 5 consistent gets 0 physical reads 0 redo size 839 bytes sent via SQL*Net to client 503 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 2 rows processed

SQL> SELECT * FROM employee SAMPLE BLOCK (50); EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO---------- ---------- --------- ---------- --------- ---------- ---------- ---------- 7369 SMITH CLERK 7902 17-DEC-80 800 20 7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30 7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30 7566 JONES MANAGER 7839 02-APR-81 2975 20 7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30 7698 BLAKE MANAGER 7839 01-MAY-81 2850 30 7782 CLARK MANAGER 7839 09-JUN-81 2450 10 7788 SCOTT ANALYST 7566 19-APR-87 3000 20 7839 KING PRESIDENT 17-NOV-81 5000 10 7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 3010 rows selected.Execution Plan---------------------------------------------------------- 0 SELECT STATEMENT Optimizer=CHOOSE (Cost=2 Card=41 Bytes=3567) 1 0 TABLE ACCESS (SAMPLE) OF 'EMPLOYEE' (Cost=2 Card=41 Bytes=3567)Statistics---------------------------------------------------------- 0 recursive calls 0 db block gets 4 consistent gets 0 physical reads 0 redo size 1162 bytes sent via SQL*Net to client 503 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 10 rows processedSQL>

SQL> select * from ( 2 select * from employee 3 order by dbms_random.value ) 4 where rownum <= 4; EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO---------- ---------- --------- ---------- --------- ---------- ---------- ---------- 7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30 7839 KING PRESIDENT 17-NOV-81 5000 10 7369 SMITH CLERK 7902 17-DEC-80 800 20 7788 SCOTT ANALYST 7566 19-APR-87 3000 20Execution Plan---------------------------------------------------------- 0 SELECT STATEMENT Optimizer=CHOOSE 1 0 COUNT (STOPKEY) 2 1 VIEW 3 2 SORT (ORDER BY STOPKEY) 4 3 TABLE ACCESS (FULL) OF 'EMPLOYEE'Statistics---------------------------------------------------------- 0 recursive calls 0 db block gets 3 consistent gets 0 physical reads 0 redo size 927 bytes sent via SQL*Net to client 503 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 1 sorts (memory) 0 sorts (disk) 4 rows processed

SQL> SELECT * FROM employee SAMPLE (40); EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO---------- ---------- --------- ---------- --------- ---------- ---------- ---------- 7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30 7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30 7698 BLAKE MANAGER 7839 01-MAY-81 2850 30 7839 KING PRESIDENT 17-NOV-81 5000 10 7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30Execution Plan---------------------------------------------------------- 0 SELECT STATEMENT Optimizer=CHOOSE (Cost=2 Card=33 Bytes=2871) 1 0 TABLE ACCESS (SAMPLE) OF 'EMPLOYEE' (Cost=2 Card=33 Bytes=2871)Statistics---------------------------------------------------------- 0 recursive calls 0 db block gets 5 consistent gets 0 physical reads 0 redo size 961 bytes sent via SQL*Net to client 503 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 5 rows processedSQL>