Multiple Materialized View Selection for XPath Query Rewriting
Bibliographic record
Abstract
We study the problem of answering XPATH queries using multiple materialized views. Despite the efforts on answering queries using single materialized view, answering queries using multiple views remains relatively new. We address two important aspects of this problem: multiple-view selection and equivalent multiple-view rewriting. With regards to the first problem, we propose an NFA-based approach (called VFILTER) to filter views that cannot be used to answer a given query. We then present the criterion for multiple view/query answerability. Based on the output of VFILTER, we further propose a heuristic method to identify a minimal view set that can answer a given query. For the problem of multiple-view rewriting, we first refine the materialized fragments of each selected view (like pushing selection), we then join the refined fragments utilizing an encoding scheme. Finally, we extract the result of the query from the materialized fragments of a single view. Experiments show the efficiency of our approach.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.010 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.002 | 0.004 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".