[Mryange]

What problem does this PR solve?

Issue Number: N/A

Related PR: #63436, #69331

Problem Summary:

Backport #63436 to branch-4.2 using the branch-4.1 adaptation from #69331. TopN lazy materialization can hang when a join produces duplicate or out-of-order physical rowids. Root cause: reusing a column iterator for these requests can underflow the RLE decoder's unsigned skip count. Group requests by segment, sort and deduplicate rowids before batch reads, then scatter results back to preserve request order and duplicate rows.

The backport preserves branch-4.2 COW ownership, Variant V2 handling, rowid range checks, file cache policy, and existing external row-fetch fixes. The existing Variant segment-reader test is adapted to the batch interface. No additional prerequisite PRs are included.

Release note

Fix TopN lazy materialization hanging on duplicate or out-of-order rowids from joins.

Check List (For Author)

• Test:
  • Regression test
  • Unit Test
  • Manual test (add detailed scripts or steps below)
    • Static checks only: clang-format 16 and git diff --check passed.
    • Build, unit tests, and SQL regression tests have not been run for this 4.2 backport.
• Behavior changed:
  • No.
  • Yes. Duplicate and out-of-order rowids are normalized before storage reads; output order and duplicates are preserved.
• Does this need documentation?
  • No.
  • Yes.

Check List (For Reviewer who merge this PR)

• Confirm the release note
• Confirm test cases
• Confirm document
• Add branch pick label

[hello-stephen]

Thank you for your contribution to Apache Doris.
Don't know what should be done next? See How to process your PR.

Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[Mryange]

run buildall

[hello-stephen]

BE UT Coverage Report

Increment line coverage 15.87% (10/63) 🎉

Increment coverage report
Complete coverage report

Category	Coverage
Function Coverage	64.26% (29893/46518)
Line Coverage	49.11% (315268/642008)
Region Coverage	44.94% (253903/564950)
Branch Coverage	46.59% (119838/257221)

[hello-stephen]

BE Regression && UT Coverage Report

Increment line coverage 96.83% (61/63) 🎉

Increment coverage report
Complete coverage report

Category	Coverage
Function Coverage	76.38% (34507/45177)
Line Coverage	61.22% (389740/636651)
Region Coverage	58.03% (328379/565871)
Branch Coverage	59.02% (151640/256937)

[yiguolei]

skip buildall