Live ORACLE

DECLARE
 TYPE sallist IS TABLE OF employees.salary%TYPE;
 sals  SALLIST;
BEGIN
 -- Limit the number of rows to 50
 SELECT salary
 BULK COLLECT INTO sals
 FROM   employees
 WHERE  ROWNUM <= 50;
 -- Retrieve 10% (approximately) of the rows in the table
 SELECT salary
 BULK COLLECT INTO sals
 FROM   employees SAMPLE ( 10 );
END;
/  

Using the Pseudocolumn ROWNUM to Limit Query Results