Query Optimization and Execution in a Parallel Analytics DBMS
Bibliographic record
Abstract
Over the past 15 years, data warehousing and OLAP technologies have matured to the point whereby they have become a cornerstone for the decision making process in organizations of all sizes. With the underlying databases growing enormously in size, parallel DBM systems have become a popular target platform. Perhaps the most ``obvious'' approach to scalable warehousing is to combine a small collection of conventional relational DBMSs into a loosely connected parallel DBMS. Such systems, however, benefit little, if at all, from advances in OLAP indexing, storage, compression, modeling, or query optimization. In the current paper, we discuss a parallel analytics server that has been designed from the ground up as a high performance OLAP query engine. Moreover, its indexing and query processing model directly exploits an OLAP-specific algebra that enables performance optimizations beyond the reach of simple relational DBMS clusters. Taken together, the server provides class-leading query performance with the scalability of shared nothing databases and, perhaps most importantly, achieves this balance with a modest physical architecture.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.003 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".