Let the scan see stable state of portions during the whole scan in Column Shards

[kirillvasilenko]

fixes #26726

Here we reuse the existing way of understanding if a portion is conflicting with the current tx, and build the stable meaningful state that the scan logic uses.

Also noticed that TSourceConstructor.SourceId field is ui32, but we pass there ui64 value (portionId). So I fixed that as well.

[github-actions]

🟢 2025-10-14 18:11:42 UTC The validation of the Pull Request description is successful.

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⚪ 2025-10-14 17:38:22 UTC Pre-commit check linux-x86_64-release-asan for dc02b8d has started.
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[Copilot]

Pull Request Overview

This PR implements a mechanism to provide a stable view of portion states during the entire scan operation in Column Shards. The changes replace the previous EPortionCommitStatus enum-based approach with a new TPortionStateAtScanStart struct that captures portion state at scan initiation time, preventing anomalies caused by portions changing state during scan execution.

• Replaced EPortionCommitStatus enum with TPortionStateAtScanStart struct containing committed, conflicting, and snapshot information
• Updated logic in both simple and plain readers to use the new stable state mechanism
• Refactored conflict detection and duplicate filtering to work with the new state representation

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
ydb/core/tx/columnshard/engines/reader/simple_reader/iterator/source.cpp	Updated portion state checking and conflict detection logic
ydb/core/tx/columnshard/engines/reader/simple_reader/iterator/context.cpp	Modified fetching plan logic and duplicate filtering to use new state
ydb/core/tx/columnshard/engines/reader/simple_reader/iterator/collections/constructors.h	Changed SourceId type and reformatted constructor
ydb/core/tx/columnshard/engines/reader/plain_reader/iterator/source.cpp	Updated portion state checking and conflict detection logic
ydb/core/tx/columnshard/engines/reader/common_reader/iterator/context.h	Replaced enum with new struct and added state determination logic
ydb/core/tx/columnshard/engines/reader/common_reader/iterator/context.cpp	Implemented comprehensive portion state determination logic
ydb/core/tx/columnshard/engines/reader/common_reader/constructor/read_metadata.h	Added new method and removed old one
ydb/core/tx/columnshard/engines/reader/common_reader/constructor/read_metadata.cpp	Updated initialization logic and removed old method
ydb/core/tx/columnshard/engines/portions/written.h	Reorganized method placement in class

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[github-actions]

⚪ 2025-10-14 18:10:15 UTC Pre-commit check linux-x86_64-release-asan for 6c97773 has started.
⚪ 2025-10-14 18:10:29 UTC Artifacts will be uploaded here
⚪ 2025-10-14 18:14:15 UTC ya make is running...
🟡 2025-10-14 20:32:14 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
15862	15408	0	142	292	20

🟢 2025-10-14 20:32:19 UTC Build successful.
🟢 2025-10-14 20:32:42 UTC ydbd size 3.8 GiB changed* by -56 Bytes, which is <= 0 Bytes vs main: OK

ydbd size dash	main: 1673452	merge: 6c97773	diff	diff %
ydbd size	4 031 887 144 Bytes	4 031 887 088 Bytes	-56 Bytes	-0.000%
ydbd stripped size	1 497 433 600 Bytes	1 497 433 696 Bytes	+96 Bytes	+0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[github-actions]

⚪ 2025-10-14 18:10:51 UTC Pre-commit check linux-x86_64-relwithdebinfo for 6c97773 has started.
⚪ 2025-10-14 18:11:05 UTC Artifacts will be uploaded here
⚪ 2025-10-14 18:14:41 UTC ya make is running...
🟡 2025-10-14 19:53:06 UTC Some tests failed, follow the links below. Going to retry failed tests...

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
39025	36254	0	1	2744	26

⚪ 2025-10-14 19:53:14 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-10-14 20:10:49 UTC Tests successful.

Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
730 (only retried tests)	708	0	0	0	22

🟢 2025-10-14 20:10:54 UTC Build successful.
🟢 2025-10-14 20:11:12 UTC ydbd size 2.3 GiB changed* by +43.5 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 9c08324	merge: 6c97773	diff	diff %
ydbd size	2 423 377 720 Bytes	2 423 422 272 Bytes	+43.5 KiB	+0.002%
ydbd stripped size	515 870 856 Bytes	515 874 056 Bytes	+3.1 KiB	+0.001%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[dorooleg]

хм, а portion id получается ui64?

[kirillvasilenko]

Получается так. Прямо в этом классе есть метод ui64 DoGetEntityId() который возвращает SourceId. Плюс конструктор выставляет это поле вот так SourceId(portion->GetPortionId()), portion->GetPortionId() тоже возвращает ui64.