OptiQL: Robust Optimistic Locking for Memory-Optimized Indexes
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Modern memory-optimized indexes often use optimistic locks for concurrent accesses. Read operations can proceed optimistically without taking the lock, greatly improving performance on multicore CPUs. But this is at the cost of robustness against contention where many threads contend on a small set of locks, causing excessive cacheline invalidation, interconnect traffic and eventually performance collapse. Yet existing solutions often sacrifice desired properties such as compact 8-byte lock size and fairness among lock requesters. This paper presents optimistic queuing lock (OptiQL), a new optimistic lock for database indexing to solve this problem. OptiQL extends the classic MCS lock---a fair, compact and robust mutual exclusion lock---with optimistic read capabilities for index workloads to achieve both robustness and high performance while maintaining various desirable properties. Evaluation using memory-optimized B+-trees on a 40-core, dual-socket server shows that OptiQL matches existing optimistic locks for read operations, while avoiding performance collapse under high contention.
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Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.011 | 0.007 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it