Results 1 
5 of
5
Streamable Fragments of Forward XPath
 16TH INTERNATIONAL CONFERENCE ON IMPLEMENTATION AND APPLICATION OF AUTOMATA
, 2011
"... We present a query answering algorithm for a fragment of Forward XPath on Xml streams that we obtain by compilation to deterministic nested word automata. Our algorithm is earliest and in polynomial time. This proves the finite streamability of the fragment of Forward XPath with child steps, outerm ..."
Abstract

Cited by 9 (3 self)
 Add to MetaCart
(Show Context)
We present a query answering algorithm for a fragment of Forward XPath on Xml streams that we obtain by compilation to deterministic nested word automata. Our algorithm is earliest and in polynomial time. This proves the finite streamability of the fragment of Forward XPath with child steps, outermostdescendant steps, label tests, negation, and conjunction (aka filters), under the reasonable assumption that the number of conjunctions is bounded. We also prove that finite streamability fails without this assumption except if P=NP.
XQuery and Static Typing: Tackling the Problem of Backward Axes
, 2013
"... Abstract. XQuery is a functional language dedicated to XML data querying and manipulation. As opposed to other W3Cstandardized languages for XML (e.g. XSLT), it has been intended to feature strong static typing. Currently, however, some expressions of the language cannot be statically typed with an ..."
Abstract
 Add to MetaCart
Abstract. XQuery is a functional language dedicated to XML data querying and manipulation. As opposed to other W3Cstandardized languages for XML (e.g. XSLT), it has been intended to feature strong static typing. Currently, however, some expressions of the language cannot be statically typed with any precision. We argue that this is due to a discrepancy between the semantics of the language and its type algebra: namely, the values of the language are (possibly inner) tree nodes, which may have siblings and ancestors in the data. The types on the other hand are regular tree types, as usual in the XML world: they describe sets of trees. The type associated to a node then corresponds to the subtree whose root is that node and contains no information about the rest of the data. This makes navigational expressions using ‘backward axes,’ which return e.g. the siblings of a node, impossible to type. We discuss how to solve this discrepancy and propose a compromise: to use extended types representing possibly inner tree nodes in some key parts of a program, and to cut out the subtrees from their original context in the rest. 1
Optimized XPath translation to query automata
"... Linear Temporal Logic (LTL) is one of the main tools used extensively in the field of verification, where many efficient modelchecking algorithms have been developed over the years. Recently a tree analog of LTL has been proposed, where a modification of the LTLtoAutomata translation was introduc ..."
Abstract
 Add to MetaCart
(Show Context)
Linear Temporal Logic (LTL) is one of the main tools used extensively in the field of verification, where many efficient modelchecking algorithms have been developed over the years. Recently a tree analog of LTL has been proposed, where a modification of the LTLtoAutomata translation was introduced. This made it possible to use automata techniques for reasoning about properties of XML queries and specifications such as containment of XPath expressions, optimisation of XPath expressions under schema constraints, and security properties of XML views. However, as the size of the constructed automata grows, there is a need for optimisation techniques to reduce the size of constructed automata. The goal of this report is to construct an optimised automaton and to implement the translation from XPath to automata and use it on XML reasoning tasks. i Acknowledgements I would like to thank my supervisor, Professor. Leonid Libkin for introducing me to the world of automata and their connection with database systems. I am also grateful to Tony Tan for his support and guidance throughout the project and for his patience with me!
Monadic Datalog Containment Streaming Tree Transducers 〈 /title 〉
, 2013
"... XML documents: An example 〈 conference 〉 〈 track 〉 〈 session 〉 〈 talk 〉 〈 title 〉 ..."
Abstract
 Add to MetaCart
XML documents: An example 〈 conference 〉 〈 track 〉 〈 session 〉 〈 talk 〉 〈 title 〉
Type Synthesis for the Logical Solver: an Approach based on Query Automata
, 2013
"... The logical solver used in [4] currently looks for a finite tree over which the logical formula is satisfied. As described in [1], we propose to study how to compute the set of all satisfying trees. One difficulty is to build a workable yet succinct representation for the synthesized type from the l ..."
Abstract
 Add to MetaCart
(Show Context)
The logical solver used in [4] currently looks for a finite tree over which the logical formula is satisfied. As described in [1], we propose to study how to compute the set of all satisfying trees. One difficulty is to build a workable yet succinct representation for the synthesized type from the logical model of