tree 6df27efc38f0b73e4202202daec710d1227c6931
parent fe3ef20d6418c4ed8965b2d61bf1d32b551e7b53
author Hyukjin Kwon <gurwls223@apache.org> 1715163486 +0900
committer Hyukjin Kwon <gurwls223@apache.org> 1715163486 +0900

[SPARK-47965][SQL][FOLLOW-UP] Uses `null` as its default value for `OptionalConfigEntry`

### What changes were proposed in this pull request?

This PR partially reverts https://github.com/apache/spark/pull/46197 because of the behaviour change below:

```python
>>> spark.conf.get("spark.sql.optimizer.excludedRules")
'<undefined>'
```

### Why are the changes needed?

To avoid behaviour change.

### Does this PR introduce _any_ user-facing change?

No, the main change has not been released out yet.

### How was this patch tested?

Manually as described above.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes #46472 from HyukjinKwon/SPARK-47965-followup.

Authored-by: Hyukjin Kwon <gurwls223@apache.org>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>