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cleanup temporary table entry from snapshot_detached_tables during table drop#88617

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nickitat merged 2 commits intoClickHouse:masterfrom
pranavmehta94:pranav/global-in-fix
Oct 17, 2025
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cleanup temporary table entry from snapshot_detached_tables during table drop#88617
nickitat merged 2 commits intoClickHouse:masterfrom
pranavmehta94:pranav/global-in-fix

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@pranavmehta94 pranavmehta94 commented Oct 16, 2025 •
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Temporary tables are auto-created when using distributed queries with GLOBAL IN. These tables use the Memory Database engine and are passed to remote servers during distributed query processing.
In DatabaseMemory::dropTable, when a table is dropped, the cleanup steps are as follows:

  • Removes from tables map (via detachTableUnlocked)
  • Removes create query from create_queries map
  • Removes UUID mapping from UUID registry
  • Missing cleanup: detached table entry remains in snapshot_detached_tables

This residual metadata is retained indefinitely, leading to a memory leak proportional to the rate of temporary table creation.

This PR does the following:

  • Modify DatabaseMemory::dropTable to ensure complete cleanup by erasing detached table entry from snapshot_detached_tables

This PR fixes #88615

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  • Improvement

Changelog entry (a user-readable short description of the changes that goes into CHANGELOG.md):

Fixes memory leak due to GLOBAL IN (#88615)

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CLAassistant commented Oct 16, 2025 •
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@nickitat nickitat self-assigned this Oct 16, 2025
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clickhouse-gh bot commented Oct 16, 2025 •
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Workflow [PR], commit [2392a94]

Summary: ❌

job_name test_name status info comment
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python3 ./ci/jobs/scripts/workflow_hooks/new_tests_check.py failure

@clickhouse-gh clickhouse-gh bot added the pr-bugfix Pull request with bugfix, not backported by default label Oct 16, 2025
@nickitat nickitat added the can be tested Allows running workflows for external contributors label Oct 16, 2025
@nickitat nickitat added this pull request to the merge queue Oct 17, 2025
Merged via the queue into ClickHouse:master with commit c89792d Oct 17, 2025
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@robot-ch-test-poll robot-ch-test-poll added the pr-synced-to-cloud The PR is synced to the cloud repo label Oct 17, 2025
@pranavmehta94 pranavmehta94 mentioned this pull request Oct 18, 2025
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@nickitat nickitat added pr-must-backport Pull request should be backported intentionally. Use this label with great care! pr-must-backport-cloud labels Oct 18, 2025
@robot-ch-test-poll2 robot-ch-test-poll2 added pr-backports-created-cloud deprecated label, NOOP pr-must-backport-synced The `*-must-backport` labels are synced into the cloud Sync PR labels Oct 18, 2025
@robot-ch-test-poll3 robot-ch-test-poll3 mentioned this pull request Oct 18, 2025
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robot-ch-test-poll3 added a commit that referenced this pull request Oct 18, 2025
@robot-ch-test-poll3
Merge pull request #88776 from ClickHouse/cherrypick/25.3/88617
5ef07da 
Cherry pick #88617 to 25.3: cleanup temporary table entry from snapshot_detached_tables during table drop
robot-clickhouse added a commit that referenced this pull request Oct 18, 2025
@robot-clickhouse
Backport #88617 to 25.3: cleanup temporary table entry from snapshot_…
dd71252 
…detached_tables during table drop
This was referenced Oct 18, 2025
Merged
Merged
robot-ch-test-poll3 added a commit that referenced this pull request Oct 18, 2025
@robot-ch-test-poll3
Merge pull request #88778 from ClickHouse/cherrypick/25.7/88617
c862993 
Cherry pick #88617 to 25.7: cleanup temporary table entry from snapshot_detached_tables during table drop
robot-clickhouse added a commit that referenced this pull request Oct 18, 2025
@robot-clickhouse
Backport #88617 to 25.7: cleanup temporary table entry from snapshot_…
907c6dc 
…detached_tables during table drop
This was referenced Oct 18, 2025
Merged
Merged
robot-ch-test-poll3 added a commit that referenced this pull request Oct 18, 2025
@robot-ch-test-poll3
Merge pull request #88780 from ClickHouse/cherrypick/25.8/88617
17f5396 
Cherry pick #88617 to 25.8: cleanup temporary table entry from snapshot_detached_tables during table drop
robot-clickhouse added a commit that referenced this pull request Oct 18, 2025
@robot-clickhouse
Backport #88617 to 25.8: cleanup temporary table entry from snapshot_…
0e23fd0 
…detached_tables during table drop
This was referenced Oct 18, 2025
Merged
Merged
robot-ch-test-poll3 added a commit that referenced this pull request Oct 18, 2025
@robot-ch-test-poll3
Merge pull request #88782 from ClickHouse/cherrypick/25.9/88617
41060bb 
Cherry pick #88617 to 25.9: cleanup temporary table entry from snapshot_detached_tables during table drop
robot-clickhouse added a commit that referenced this pull request Oct 18, 2025
@robot-clickhouse
Backport #88617 to 25.9: cleanup temporary table entry from snapshot_…
3ecf1f3 
…detached_tables during table drop
@robot-ch-test-poll3 robot-ch-test-poll3 mentioned this pull request Oct 18, 2025
Merged
@robot-clickhouse robot-clickhouse added the pr-backports-created Backport PRs are successfully created, it won't be processed by CI script anymore label Oct 18, 2025
clickhouse-gh bot added a commit that referenced this pull request Oct 18, 2025
@clickhouse-gh
Merge pull request #88779 from ClickHouse/backport/25.7/88617
d41ee02 
Backport #88617 to 25.7: cleanup temporary table entry from snapshot_detached_tables during table drop
nickitat added a commit that referenced this pull request Oct 20, 2025
@nickitat
Merge pull request #88783 from ClickHouse/backport/25.9/88617
8c20526 
Backport #88617 to 25.9: cleanup temporary table entry from snapshot_detached_tables during table drop
nickitat added a commit that referenced this pull request Oct 20, 2025
@nickitat
Merge pull request #88781 from ClickHouse/backport/25.8/88617
ab168b0 
Backport #88617 to 25.8: cleanup temporary table entry from snapshot_detached_tables during table drop
nickitat added a commit that referenced this pull request Oct 20, 2025
@nickitat
Merge pull request #88777 from ClickHouse/backport/25.3/88617
d93d5de 
Backport #88617 to 25.3: cleanup temporary table entry from snapshot_detached_tables during table drop
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can be tested Allows running workflows for external contributors pr-backports-created Backport PRs are successfully created, it won't be processed by CI script anymore pr-backports-created-cloud deprecated label, NOOP pr-bugfix Pull request with bugfix, not backported by default pr-must-backport Pull request should be backported intentionally. Use this label with great care! pr-must-backport-synced The `*-must-backport` labels are synced into the cloud Sync PR pr-synced-to-cloud The PR is synced to the cloud repo

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GLOBAL IN causes Memory Leak

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