YQ-4857 forbidden change of external data source type if it has dependencies

[GrigoriyPA]

Changelog entry

Forbidden change of external data source type if it has dependencies

Changelog category

• Bugfix

Description for reviewers

Bugfix ticket: https://st.yandex-team.ru/YQ-4857

[github-actions]

⚪ 2025-11-03 16:14:27 UTC Pre-commit check linux-x86_64-release-asan for e9d69b6 has started.
⚪ 2025-11-03 16:14:50 UTC Artifacts will be uploaded here
⚪ 2025-11-03 16:16:13 UTC ya make is running...
🟡 2025-11-03 18:13:18 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?
15532	14968	0	244	294	26

🟢 2025-11-03 18:13:25 UTC Build successful.
🟢 2025-11-03 18:13:48 UTC ydbd size 3.8 GiB changed* by +9.7 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 802fb8a	merge: e9d69b6	diff	diff %
ydbd size	4 068 675 512 Bytes	4 068 685 416 Bytes	+9.7 KiB	+0.000%
ydbd stripped size	1 510 375 912 Bytes	1 510 378 920 Bytes	+2.9 KiB	+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}

[Copilot]

Pull Request Overview

This pull request refactors the external data source creation and alteration logic, and adds validation to prevent changing the source type when the data source is in use. The main changes include:

• Refactored CreateExternalDataSource to use modern C++ patterns (MakeIntrusive instead of new, direct assignment instead of CopyFrom)
• Added validation to prevent changing external data source type when it's referenced by other entities
• Improved code formatting and namespace organization
• Added comprehensive test coverage for the new validation logic

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
ydb/core/tx/schemeshard/schemeshard__operation_common_external_data_source.cpp	Refactored CreateExternalDataSource function to use MakeIntrusive and direct assignment for protobuf fields
ydb/core/tx/schemeshard/schemeshard__operation_alter_external_data_source.cpp	Added validation to prevent source type changes when data source is in use; improved code formatting and namespace organization
ydb/core/kqp/ut/scheme/kqp_scheme_ut.cpp	Added tests for source type change validation and CREATE OR REPLACE functionality
ydb/core/kqp/gateway/kqp_metadata_loader.cpp	Added type mismatch validation between external table and data source; improved code comments

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[github-actions]

🟢 2025-11-03 16:17:11 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-11-03 16:17:39 UTC Pre-commit check linux-x86_64-relwithdebinfo for e9d69b6 has started.
⚪ 2025-11-03 16:17:55 UTC Artifacts will be uploaded here
⚪ 2025-11-03 16:19:22 UTC ya make is running...
🟡 2025-11-03 17:54:42 UTC Some tests failed, follow the links below. Going to retry failed tests...

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
39125	36303	0	1	2791	30

⚪ 2025-11-03 17:54:54 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-11-03 18:07:40 UTC Tests successful.

Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
57 (only retried tests)	41	0	0	0	16

🟢 2025-11-03 18:07:43 UTC Build successful.
🟢 2025-11-03 18:08:01 UTC ydbd size 2.3 GiB changed* by +10.1 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 802fb8a	merge: e9d69b6	diff	diff %
ydbd size	2 429 287 080 Bytes	2 429 297 400 Bytes	+10.1 KiB	+0.000%
ydbd stripped size	516 135 944 Bytes	516 141 000 Bytes	+4.9 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}