Oracle 21c

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--instead of using first
WITH
    s (a, b)
    AS
        (SELECT 1, 'ff' FROM DUAL
         UNION ALL
         SELECT 1, 'ee' FROM DUAL
         UNION ALL
         SELECT 1, 'ee' FROM DUAL
         UNION ALL
         SELECT 2, 'ee' FROM DUAL),
    t (a, b)
    AS
        (  SELECT s.a, COLLECT (s.b)
             FROM s
         GROUP BY s.a),
    v (a, b)
    AS
        (SELECT t.a, tb.b
           FROM t
                OUTER APPLY (SELECT x.COLUMN_VALUE     b
                               FROM TABLE (t.b) x
                              FETCH FIRST 1 ROW ONLY) tb)
SELECT *
  FROM v;


A
B


1
ff

2
ee


--instead of using count
WITH
    s (a, b)
    AS
        (SELECT 1, 'ff' FROM DUAL
         UNION ALL
         SELECT 1, 'ee' FROM DUAL
         UNION ALL
         SELECT 1, 'ee' FROM DUAL
         UNION ALL
         SELECT 2, 'ee' FROM DUAL),
    t (a, b)
    AS
        (  SELECT s.a, COLLECT (s.b)
             FROM s
         GROUP BY s.a),
    v (a, b)
    AS
        (SELECT t.a, tb.b
           FROM t
                OUTER APPLY (SELECT count(*)    b
                               FROM TABLE (t.b) x
                              FETCH FIRST 1 ROW ONLY) tb)
SELECT *
  FROM v;


A
B


1
3

2
1


--instead of using get the second element.

WITH
    s (a, b)
    AS
        (SELECT 1, 'ff' FROM DUAL
         UNION ALL
         SELECT 1, 'ee' FROM DUAL
         UNION ALL
         SELECT 1, 'ee2' FROM DUAL
         UNION ALL
         SELECT 2, 'ee' FROM DUAL),
    t (a, b)
    AS
        (  SELECT s.a, COLLECT (s.b)
             FROM s
         GROUP BY s.a),
    v (a, b)
    AS
        (SELECT t.a, tb.b
           FROM t
                OUTER APPLY (SELECT x.COLUMN_VALUE     b
                               FROM TABLE (t.b) x
                               OFFSET 1 ROW
                              FETCH FIRST 1 ROW ONLY) tb)
SELECT *
  FROM v;


A
B


1
ee2

2
null
A	B
1	ee2
2	null