[contrueCT]

Purpose of the PR

Topling's standalone OLAP property clear still drops and recreates the same column family. The previously reported real-JNI reproduction completes the clear task, then aborts during normal shutdown. This change clears the selected table while retaining its CF handle.

Addresses the OLAP clear/close item already tracked in #3242 and the original review. The release checklist stays open. Existing Topling and recovery PRs were checked; the merged runtime integration and snapshot-recovery fix #3293 do not cover this clear path.

Main Changes

• Clear the selected OLAP table in its owning database under the store write lock.
• Retain Topling CF handles and discard the clearing thread's pending batch before committing the clear; leave other threads' leases untouched.
• Preserve the standard RocksDB drop/create path.
• Adapt OLAP test fixtures to the shared AtomicReference owner introduced by merged fix(rocksdb): make snapshot restore retryable #3293.

Verifying these changes

• Trivial rework / code cleanup without any test coverage. (No Need)
• RocksDBSessionsTest: 29 tests pass on Java 17, with no failures/errors/skips. Coverage includes retained handle identity, recreation on each repeated standard clear, pending writes outside the stored range and in an empty table, independent OLAP routing, other-table preservation, reuse and close/reopen reads. A second-thread test verifies that a batch staged before clear can repopulate the table when committed afterward.
• Isolated negative controls fail as expected when the second standard clear skips handle recreation or when OLAP clear resets other threads' pending batches.
• Whole-repository Java 17 clean compilation, editorconfig formatting and git diff --check pass.

These tests run the Topling Java branch with the real standard RocksDB JNI. The same handle-preservation regression fails against the original master adapter. Actual Topling JNI and its reported shutdown abort were not rerun on this macOS arm64 host; current-head Linux native qualification remains necessary.

Does this PR potentially affect the following parts?

• Dependencies
• Modify configurations
• The public API
• Other affects: standalone Topling OLAP clear and native handle lifecycle
• Nope

Documentation Status

• Doc - TODO
• Doc - Done: docs/storage-lifecycle.md documents OLAP clear, handle retention and pending-write handling, including later commits from concurrent writers and the difference from graph truncate.
• Doc - No Need

Conceptual overview

Topling OLAP clear 保留 CF handle，标准 RocksDB 仍走 drop/create，实际 Topling JNI 验收仍需完成。

Conceptual illustration; not test or release-acceptance evidence.

English conceptual overview

Concept illustration of the Topling OLAP clear path: reset the clearing thread's pending batch, clear the selected table in its owning database, and retain the CF handle. Standard RocksDB retains drop/create; actual Topling JNI qualification remains required.

[codecov]

Codecov Report

❌ Patch coverage is 87.50000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 56.21%. Comparing base (87a06a9) to head (cd52723).
⚠️ Report is 102 commits behind head on master.

Files with missing lines	Patch %	Lines
.../hugegraph/backend/store/rocksdb/RocksDBStore.java	87.50%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@              Coverage Diff              @@
##             master    #3299       +/-   ##
=============================================
+ Coverage     41.92%   56.21%   +14.28%     
+ Complexity     7101      378     -6723     
=============================================
  Files           770      508      -262     
  Lines         67320    49201    -18119     
  Branches       9042     7166     -1876     
=============================================
- Hits          28226    27656      -570     
+ Misses        35879    18824    -17055     
+ Partials       3215     2721      -494     

Flag	Coverage Δ
server_memory	56.21% <87.50%> (?)

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[bitflicker64]

Blocking: no. Summary: The Topling branch clears the selected OLAP table through the existing RocksDBSessions.clearTables path under the store write lock, with balanced useSession/close and the standard drop/create path unchanged; no correctness defect found in the Java change, two small test-coverage notes inline. Real Topling JNI shutdown behaviour was not exercised by this review or by CI. Evidence: read the full diff at 34cc360 against merge base 87a06a9 plus RocksDBStore, RocksDBSessions.clearTables, BackendSessionPool, RocksDBStdSessions.StdSession and the callers (GraphTransaction.clearOlapPk, OlapPropertyKeyClearJob); RocksDBSstStore does not inherit clearOlapTable so the SST backend is unaffected; CI job build-server / server_memory (Java 17) ran UnitTestSuite at this head: 999 tests, 0 failures, 0 errors.