Oracle 18c

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CREATE TABLE test_data ( p_id, age ) AS
SELECT '00170', 64 FROM DUAL UNION ALL
SELECT '00170', 64 FROM DUAL UNION ALL
SELECT '00201', 24 FROM DUAL UNION ALL
SELECT '00201', 64 FROM DUAL UNION ALL
SELECT '00201', 64 FROM DUAL UNION ALL
SELECT '00300', 24 FROM DUAL UNION ALL  
SELECT '00300', 20 FROM DUAL;
7 rows affected

SELECT p_id,
       age
FROM   (
  SELECT t.*,
         MAX( ROWNUM ) OVER ( PARTITION BY p_id ) AS grp
  FROM   (
    SELECT *
    FROM   test_data
    ORDER BY p_id
  ) t
)
WHERE  grp <= 4;


P_ID
AGE


00170
64

00170
64


SELECT p_id,
       age
FROM   (
  SELECT t.*,
         MAX( ROWNUM ) OVER ( PARTITION BY p_id ) AS grp
  FROM   (
    SELECT *
    FROM   test_data
    ORDER BY p_id
  ) t
)
WHERE  grp <= 5;


P_ID
AGE


00170
64

00170
64

00201
24

00201
64

00201
64


SELECT p_id,
       age
FROM   (
  SELECT t.*,
         MAX( ROWNUM ) OVER ( PARTITION BY p_id ) AS grp
  FROM   (
    SELECT *
    FROM   test_data
    ORDER BY p_id
  ) t
)
WHERE  grp <= 6;


P_ID
AGE


00170
64

00170
64

00201
24

00201
64

00201
64