Oracle 21c

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CREATE TABLE table_name (value) AS
SELECT 'ab^bc^ab^de' FROM DUAL UNION ALL
SELECT 'mn^mn^op' FROM DUAL UNION ALL
SELECT 'ab^bc^ab^de' FROM DUAL UNION ALL
SELECT 'one^two^three^one^two^one^four' FROM DUAL;
4 rows affected

WITH bounds ( rid, value, spos, epos ) AS (
  SELECT ROWID, value, 1, INSTR(value, '^', 1)
  FROM   table_name
UNION ALL
  SELECT rid, value, epos + 1, INSTR(value, '^', epos + 1)
  FROM   bounds
  WHERE  epos > 0
)
SELECT LISTAGG(
         DISTINCT 
         CASE epos
         WHEN 0
         THEN SUBSTR(value, spos)
         ELSE SUBSTR(value, spos, epos - spos)
         END,
         '^'
       ) WITHIN GROUP (ORDER BY spos) AS unique_values
FROM   bounds
GROUP BY rid;


UNIQUE_VALUES


ab^bc^de

mn^op

ab^bc^de

one^two^three^four


WITH bounds ( rid, value, spos, epos ) AS (
  SELECT ROWID, value, 1, INSTR(value, '^', 1)
  FROM   table_name
UNION ALL
  SELECT rid, value, epos + 1, INSTR(value, '^', epos + 1)
  FROM   bounds
  WHERE  epos > 0
),
words (rid, word, spos) AS (
  SELECT rid,
         CASE epos
         WHEN 0
         THEN SUBSTR(value, spos)
         ELSE SUBSTR(value, spos, epos - spos)
         END,
         spos
  FROM   bounds
),
unique_words ( rid, word, spos ) AS (
  SELECT rid,
         word,
         MIN(spos)
  FROM   words
  GROUP BY rid, word
)
SELECT LISTAGG(word, '^') WITHIN GROUP (ORDER BY spos) AS unique_values
FROM   unique_words
GROUP BY rid;


UNIQUE_VALUES


ab^bc^de

mn^op

ab^bc^de

one^two^three^four