When Can We Answer Queries Using Result-Bounded Data Interfaces?
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Published:2022-06-02
Issue:
Volume:Volume 18, Issue 2
Page:
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ISSN:1860-5974
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Container-title:Logical Methods in Computer Science
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language:en
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Short-container-title:
Author:
Amarilli Antoine,Benedikt Michael
Abstract
We consider answering queries on data available through access methods, that
provide lookup access to the tuples matching a given binding. Such interfaces
are common on the Web; further, they often have bounds on how many results they
can return, e.g., because of pagination or rate limits. We thus study
result-bounded methods, which may return only a limited number of tuples. We
study how to decide if a query is answerable using result-bounded methods,
i.e., how to compute a plan that returns all answers to the query using the
methods, assuming that the underlying data satisfies some integrity
constraints. We first show how to reduce answerability to a query containment
problem with constraints. Second, we show "schema simplification" theorems
describing when and how result-bounded services can be used. Finally, we use
these theorems to give decidability and complexity results about answerability
for common constraint classes.
Funder
UK Research and Innovation
Publisher
Centre pour la Communication Scientifique Directe (CCSD)
Subject
General Computer Science,Theoretical Computer Science