hussein-awala commented on issue #56561:
URL: https://github.com/apache/airflow/issues/56561#issuecomment-3393129334
I did some debugging and here is what I found. The XCom value lose the key
orders in the DB:
```sql
select * from xcom where task_id='create' and key='return_value';
dag_run_id | task_id | map_index | key | dag_id |
run_id | value | timestamp
------------+---------+-----------+--------------+--------+------------------------------------------+--------------------------+-------------------------------
8 | create | -1 | return_value | d1 |
manual__2025-10-11T09:43:25.379548+00:00 | {"A": 3, "B": 2, "C": 1} |
2025-10-11 09:43:26.917442+00
(1 row)
```
Why?
It's because we store the value as a `JSON` for all the DBs except for
PostgreSQL where we use `JSONB`:
```python
value = Column(JSON().with_variant(postgresql.JSONB, "postgresql"))
```
- `JSON` keeps insertion order of keys (the exact string representation) —
slower to query, faster to insert.
- `JSONB` reorders keys arbitrarily and removes duplicates during storage —
faster to query, slower to insert.
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