Abstract
We consider the view-based query determinacy problem over graph databases for queries defined as unions of path queries. These queries select pairs of nodes in a graph that are connected through a path whose length falls in a given set. A view specification is a set of such queries. We say that a view specification V determines a query Q if, for all databases D, the answers to V on D contain enough information to answer Q. Our main result states that, given a view V, there exists an explicit bound that depends on V such that we can decide the determinacy problem for all queries that ask for a path longer than this bound, and provide first-order rewritings for the queries that are determined. We call this notion asymptotic determinacy. As a corollary, we can also compute the set of almost all path queries that are determined by V.
Highlights
View determinacy is a static analysis problem on databases that consists in deciding whether a given set of initial queries, called a view, contains enough information to answer a new query, and this on all databases
We show that, given a view V defined by unions of path queries, we can decide whether V determines a path query Q assuming Q is “big enough,” that is, Q asks for the existence of a path longer than some n0 that we can effectively compute from V
Given a view V defined by unions of path queries, we can decide determinacy of almost all path queries Q
Summary
View determinacy is a static analysis problem on databases that consists in deciding whether a given set of initial queries, called a view, contains enough information to answer a new query, and this on all databases. We show that, given a view V defined by unions of path queries, we can decide whether V determines a path query Q assuming Q is “big enough,” that is, Q asks for the existence of a path longer than some n0 that we can effectively compute from V. The finite number of small queries that we are not able to process are cases where both our criterion of determinacy and our generic counter-examples fail
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
