[SPARK-32648][SS] Remove unused DELETE_ACTION in FileStreamSinkLog

[michal-wieleba]

What changes were proposed in this pull request?

Removing unused DELETE_ACTION in FileStreamSinkLog.

Why are the changes needed?

DELETE_ACTION is not used nowhere in the code.

Does this PR introduce any user-facing change?

No

How was this patch tested?

Tests where not added, because code was removed.

[HeartSaVioR]

ok to test

[HeartSaVioR]

I'm OK with the changes, but given the idea was from me, it would be safer to review from others as well.

cc. @dongjoon-hyun @gatorsmile

[SparkQA]

Test build #127779 has finished for PR 29505 at commit e50fddb.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[dongjoon-hyun]

Thank you for pinging me, @HeartSaVioR . Yes, I agree with you.
It looks function-wise safe inside Apache Spark, but deleting something needs more wider agreement.

cc @tdas , @zsxwing , @marmbrus , @cloud-fan , too.

[zsxwing]

Removing it sounds good to me. After #28904, we won't be able to support DELETE_ACTION without upgrading the log version. If we really need this, we can add it back with a new log format.

[dongjoon-hyun]

Thank you, @zsxwing . Merged to master for Apache Spark 3.1.0 on December 2020.

[dongjoon-hyun]

Thank you and welcome, @michal-wieleba .
You are added to the Apache Spark contributor group and SPARK-32648 is assigned to you.