sharetheknowledge opened a new issue, #69868:
URL: https://github.com/apache/airflow/issues/69868
### Under which category would you file this issue?
Providers
### Apache Airflow version
3.3.0 (bug confirmed present via source review; also reproduced hands-on on
3.2.2, and confirmed present on `main` as of 2026-07-14)
### What happened and how to reproduce it?
`airflow.cfg`'s `[scheduler] create_delta_data_intervals` setting is never
read anywhere in the codebase - it has no effect. Meanwhile `[scheduler]
create_cron_data_intervals` silently controls timetable selection for **both**
cron-string schedules (documented) **and** `timedelta`/`relativedelta`
schedules (undocumented, and contradicts `config.yml`'s own description of what
`create_delta_data_intervals` is supposed to do).
Root cause is in `_create_timetable()` in
`task-sdk/src/airflow/sdk/definitions/dag.py` (lines 148–169 on `main` / 3.3.0):
```python
if isinstance(interval, timedelta | relativedelta):
if airflow_conf.getboolean("scheduler", "create_cron_data_intervals"):
# <-- should be create_delta_data_intervals
return DeltaDataIntervalTimetable(interval)
return DeltaTriggerTimetable(interval)
if isinstance(interval, str):
if airflow_conf.getboolean("scheduler", "create_cron_data_intervals"):
return CronDataIntervalTimetable(interval, timezone)
return CronTriggerTimetable(interval, timezone=timezone)
```
Both branches check the same config key, `create_cron_data_intervals`. The
`timedelta`/`relativedelta` branch should check `create_delta_data_intervals`
instead, per `config.yml`'s own description of that setting
(`airflow-core/src/airflow/config_templates/config.yml`,
`create_delta_data_intervals` entry).
**Steps to reproduce**
1. Use any DAG scheduled with a plain `timedelta`, e.g. the stock `tutorial`
DAG:
```python
schedule=timedelta(days=1)
```
2. In `airflow.cfg`, set:
```
[scheduler]
create_delta_data_intervals = True
```
3. Confirm the config is actually being read:
```python
from airflow.configuration import conf
print(conf.getboolean("scheduler", "create_delta_data_intervals")) #
prints True
```
4. Load the DAG and inspect its timetable:
```python
from airflow.models import DagBag
dag = DagBag().get_dag("tutorial")
print(type(dag.timetable))
```
**Result:** still `DeltaTriggerTimetable` -
`create_delta_data_intervals=True` had no effect.
5. Now instead set `create_cron_data_intervals = True` (leaving
`create_delta_data_intervals` at its default) and rerun step 4.
**Result:** `dag.timetable` becomes `DeltaDataIntervalTimetable`, even
though the DAG's schedule is a `timedelta`, not a cron string - proving the
wrong config key is being consulted.
### What you think should happen instead?
The `timedelta | relativedelta` branch of `_create_timetable()` should check
`create_delta_data_intervals`, matching what `config.yml` documents for that
setting and keeping it independent from `create_cron_data_intervals` (which
should only affect the `str`/cron branch). The fix is a one-line change:
```python
if isinstance(interval, timedelta | relativedelta):
if airflow_conf.getboolean("scheduler", "create_delta_data_intervals"):
return DeltaDataIntervalTimetable(interval)
return DeltaTriggerTimetable(interval)
```
### Operating System
Windows 11 / WSL2 (Ubuntu), reproduced via a local virtualenv install
### Deployment
Virtualenv installation
### Apache Airflow Provider(s)
_No response_
### Versions of Apache Airflow Providers
N/A
### Official Helm Chart version
Not Applicable
### Kubernetes Version
_No response_
### Helm Chart configuration
_No response_
### Docker Image customizations
_No response_
### Anything else?
Confirmed by reading source directly (not just local install):
- Installed venv (Airflow 3.2.2):
`venv/lib/python3.12/site-packages/airflow/sdk/definitions/dag.py`
- `github.com/apache/airflow` tag `3.2.2`: same code
- `github.com/apache/airflow` tag `3.3.0`: same code, lines 148–169
- `github.com/apache/airflow` branch `main`: same code, unchanged
Also confirmed `create_delta_data_intervals` is referenced nowhere else in
the codebase except:
- `airflow-core/src/airflow/cli/commands/config_command.py` (CLI config-list
metadata only)
- `config_templates/config.yml` (docs only)
- `config_templates/unit_tests.cfg` (sets it `true` for test fixtures, but
no code path reads it for this purpose)
This makes `create_delta_data_intervals` fully dead config as of at least
3.2.2 through `main`.
### Are you willing to submit PR?
- [x] Yes I am willing to submit a PR!
### Code of Conduct
- [x] I agree to follow this project's [Code of
Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)
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