Ashwani Raina has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/23348 )

Change subject: KUDU-3734 include undo size while picking rowsets
......................................................................


Patch Set 6:

(2 comments)

> Do we need to consider the undo delta's older than ancient history
 > mark? Could there be a race between them GC'd vs being compacted?

Each rowset is protected by a lock(compact_flush_lock_) while an on-going 
modifying maintenance op such as GC, compaction or flush. Once a rowset is 
selected for compaction, the lock remains until compaction is done with both 
load and commit phase. Rowset compaction also gc's ancient undo deltas (if 
any). Does that answer your question?

http://gerrit.cloudera.org:8080/#/c/23348/3//COMMIT_MSG
Commit Message:

http://gerrit.cloudera.org:8080/#/c/23348/3//COMMIT_MSG@10
PS3, Line 10: taking into consideration the size of undo deltas while picking 
rowsets
            : during rowset compaction. I could not find any historical reason 
to why
            : it was not done before. Maybe there was some analysis done that 
ended
            : in a conclusion that considering undo deltas may not be right 
approach
            : when estimating upper bound fractional solution in the knapsack.
> I took a closer look at the compaction code and it turned out you were righ
Ack


http://gerrit.cloudera.org:8080/#/c/23348/6//COMMIT_MSG
Commit Message:

PS6:
> Do you mind adding a test to track regressions if anything changes and the
Sure!
Let me take this up in a separate changelist. I have made a note.



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Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I351c0ba96a02e6ded5153adf9d981083a8c40592
Gerrit-Change-Number: 23348
Gerrit-PatchSet: 6
Gerrit-Owner: Ashwani Raina <[email protected]>
Gerrit-Reviewer: Abhishek Chennaka <[email protected]>
Gerrit-Reviewer: Alexey Serbin <[email protected]>
Gerrit-Reviewer: Ashwani Raina <[email protected]>
Gerrit-Reviewer: Attila Bukor <[email protected]>
Gerrit-Reviewer: Kudu Jenkins (120)
Gerrit-Reviewer: Kurt Deschler <[email protected]>
Gerrit-Reviewer: Marton Greber <[email protected]>
Gerrit-Comment-Date: Thu, 05 Feb 2026 12:30:09 +0000
Gerrit-HasComments: Yes

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