FROM emp SAMPLE (MYNUMBER)

[hudo]

Hello,
why does the following code work NOT with the line:
SAMPLE (mynumber )

CREATE OR REPLACE
PROCEDURE mysample
IS

mynumber NUMBER := 20;


BEGIN

DBMS_OUTPUT.PUT_LINE('mynumber:  '||mynumber);

FOR r_samp IN (
	SELECT SAL 
	FROM EMP  
	--SAMPLE ( 20 )
	SAMPLE ( mynumber )
)
LOOP

DBMS_OUTPUT.PUT_LINE('sal:  '||r_samp.SAL);


END LOOP;

DBMS_OUTPUT.PUT_LINE('mynumber:  '||mynumber);

END  mysample;