Selecting only even or odd records

Summary 

First create a table(RANDOM_VALUES) with 100 records of random values.

CREATE TABLE RANDOM_VALUES (ID NUMBER(3), col1 VARCHAR2(30));

BEGIN
    FOR i IN 1..100 LOOP
      INSERT INTO RANDOM_VALUES VALUES (i, ROUND(Dbms_Random.VALUE*100000));
    END LOOP;
    COMMIT;
  END;
  /

To select the even records from table execute

SELECT * FROM 
(SELECT ROWNUM num, ID, col1 FROM RANDOM_VALUES) 
WHERE MOD(num,2) = 0;

To select the odd records from table execute

SELECT * FROM 
(SELECT ROWNUM num, ID, col1 FROM RANDOM_VALUES) 
WHERE MOD(num,2) = 1;