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Record W2564774002

Access methods for xml query optimization

2006· article· en· W2564774002 on OpenAlex
Attila Barta

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.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

Venuenot available
Typearticle
Languageen
FieldComputer Science
TopicAdvanced Database Systems and Queries
Canadian institutionsUniversity of Toronto
Fundersnot available
KeywordsComputer scienceXML databaseStreaming XMLEfficient XML InterchangeXML validationQuery optimizationXQueryInformation retrievalXML EncryptionXML Schema EditorXPathQuery languageDocument Structure DescriptionDatabaseXML SignatureXMLWorld Wide Web
DOInot available

Abstract

fetched live from OpenAlex

An ever increasing number of organizations store their data using the XML data model. In this respect, the XML data model is used as encoding for information exchange, e-commerce messaging and complex data formats such as genome and protein data. These XML encoded data are stored in XML documents and a collection of XML documents is know as an XML database. In a simplified model, an XML document can be modeled as a tree. A challenge to the current database research is how to query these tree-encoded databases. The de facto XML query language is XQuery and there are many XQuery implementations ranging from simple XQuery prototypes to complex implementations that are part of database systems that provide XML support. The common denominator of these XQuery implementations is the immaturity of the XML query optimizer. The query optimization techniques proved to be the foundation of success for the object/relational database systems. We believe that without a sound query optimization technique querying large XML databases will not be feasible. In this thesis we present query optimization techniques for XML databases. These query optimization techniques are based on an original query optimization paradigm that we call two-level query optimization and in the context of this paradigm we introduce two novel optimization strategies, namely holistic path summary pruning and access-order selection. Furthermore, we propose the usage of path summaries (a concise representation of an XML instance) in the query optimizer as system catalogs. The query optimization techniques that we propose are employed at the access method selection level. An access method is a query operator that accesses a data sources. In this thesis we present three access methods: ToXStream, which works on streamed documents, TwigStackScan and ToXinScan that employ path summaries. The soundness of the optimization techniques that we propose are verified through experiments on XML query benchmarks. The experimental results suggest that, when applicable, these optimization techniques induce performance improvements up to two orders of magnitude over the state-of-the-art.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Theoretical or conceptual · Consensus signal: none
GenreCandidate signal: Methods · Consensus signal: Methods
Teacher disagreement score0.920
Threshold uncertainty score0.208

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.001
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.030
GPT teacher head0.386
Teacher spread0.356 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Quick stats

Citations1
Published2006
Admission routes1
Has abstractyes

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